In ‘The Flowers that Bloom in the Spring’ from The Mikado, Gilbert and Sullivan were interpreting the seasons according to their 19^th Century climate – but do these flowers still, indeed, bloom in spring? The Meteorological Office’s traditional definitions of the seasons in the UK are:

• Summer from June to August
• Autumn from September to November
• Winter from December to February
• Spring from March to May

Increasingly, climate change is blurring these distinctions, and gardeners are seeing autumn stretching well towards January. Winters in maritime Great Britain are now most severe in February and March, and summer extends into September. The effects of prolonged warm autumns include accelerated growth emergence and flowering of plants which have been thought of as the harbingers of spring.

Phenological studies in the late 20^th and early 21^st Centuries established that the then-termed ‘early-spring flowering plants’ had accelerated blossoming by as much as four weeks. Now, in the second decade of the 21^st Century, it seems this is an underestimate.

Pictured above: Iris unguicularis (styllosa); the Algerian iris

Iris unguicularis (styllosa), the Algerian iris, is renowned as an early flower of spring. It now comes into bloom in late November and very early December, making it an autumn and winter flowering plant. It originates from Algeria, Greece, Turkey, Western Syria, and Tunisia and requires freely draining, light soils with minimal nutrient value. Planted in a south facing border, Iris unguicularis is an undemanding and very colourful addition to the garden. Many early-flowering plants have highly coloured flowers which attract the widest spectrum of insect pollinators.

Pictured above: Cyclamen hederifolium

Similarly, Cyclamen hederifolium (hera meaning “ivy”, folium meaning “leaf”), now flowers vigorously from mid-December, providing colour in the garden in those darkest days prior to the winter solstice. It originates from woodland, shrubland, and rocky areas in the Mediterranean region from southern France to western Turkey and on Mediterranean islands. Once the corms are established it naturalises freely, spreading by self-seeding from explosive seed capsules which cast progeny widely in borders of light, sandy nutrient-free soil.

Pictured above: alyssum (A. saxatile)

The common rockery plant alyssum (A. saxatile), is a perennial herbaceous plant, which rapidly colonises borders and will spread down onto walls providing colour from early January. It is one of the ornamental members of the cabbage family (Brassicaceae) with bright cruciform flowers.

Each of these plants is responding to climatic warming, indicating the loss of traditional seasonality. This impairs relationships between flowering plants and animal pollinators that have carefully evolved for mutual benefit over millennia. The full consequences of these losses will be apparent in years and decades to come.

Professor Geoff Dixon is author of Garden practices and their science, published by Routledge 2019.

Composts are artificial mixtures in which seeds germinate, cuttings root and whole plants grow. Their key feature is reliability of composition. The first such composts were formulated by the John Innes Centre in the 1900s. Researchers needed preparations which allowed reliable growth of plants for experiments. The main ingredients were loamy soil, sand and lime plus nutrients. John Innes composts subsequently became the mainstay of horticulturists and gardeners.

Colourful flowering in artificial composts.

Variability in the loam and its weight were major disadvantages. Scientists at the University of California solved these problems by preparing mixtures of peat, sand and nutrients. Air fill porosity characteristics of ‘UC mixes’, as they became known, allow healthy seed germination, root production, growth and flowering. Lighter weight is of major significance, allowing the easy movement of plants. Arguably, simplified transport also resulted in the advent of garden centres and freer international plant trading. As a result, the garden centre industry has become a regular social feature.

A peat extraction site.

Peat, while of major importance, is now seen as the ‘achilles heel’ of these composts. Peat bogs are very significant reservoirs for carbon dioxide and major participants in the drive for reducing the impact of climate change. The compost industry strips peat from the bogs and then mixes it into specialised formulations for seed germination or plant growth. The bogs can be reclaimed and will restart the processes of CO₂ absorption, but there is still a significant environmental penalty. Social and political pressures are driving peat reduction and its elimination from garden and commercially used composts. Peat substitutes must have the key properties of adequate air fill porosity, light weight and minimal or net zero carbon demand.

A renovated peat extraction site.

One suggestion is using coir – waste arising from coconut harvesting. Like peat, this is a natural, biodegradable product. When shredded it forms a useful peat substitute, an alternative is well composted bark and fine wood chippings, which are mixed with sand. Both are valuable composts for growing ornamental plants and germinating their seedlings. Some manufacturers are also adding loamy soil into these formulae. Problems continue, however, with finding peat-free formulae for use in commercial transplant propagation. Germinating vegetable seedlings for large scale crops requires absolute regularity and reliability. Uniform, vigorous seedlings result in mature high-quality crops suitable for once over harvesting and scheduling which meets supermarkets’ specifications.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

As we speak, apples and pears are ripening on the trees. But how do you grow apple and pear trees from scratch and keep them alive? Our resident gardening expert, Professor Geoff Dixon, investigates.

Autumn is the ‘season of mists and mellow fruitfulness’, as John Keats said in his Ode to Autumn. It is a time for harvesting temperate tree fruits, especially apples and pears in gardens and orchards.

This fruit is distinctive and delicious. The ‘Sunset’ apple cultivar, derived from the Cox’s Orange Pippin, produces red and gold striped fruit and sweet tasting flesh, while the French pear cultivar doyenne du comice has the most superb taste if caught at peak ripeness.

The sunset apple.

Both apples and pears ripen after harvesting, emitting ethylene and passing through a climacteric, or critical biological stage. When respiration reaches a peak, the fruits’ flavour is most satisfying.

Both apples and pears are best planted in late autumn or during winter when the trees are dormant, either as container-grown or preferably bare root trees. Place each tree in a hole that is large enough for the entire root system, ensuring that the graft union sits well above the soil level.

Each tree consists of two parts: the rootstock, selected originally from wild species, and the scion, which is the fruiting cultivar. Apple cultivars mostly dwarf Malling no. 9, and pear scions are grafted onto quince rootstocks. A stake should be driven into the hole before putting the tree in place.

Pour ample water into the hole, keeping the roots wet. Do so again once soil is replaced and firmed round the tree. As the tree establishes and produces leaves and flowers, water well and regularly, especially during dry periods.

French pear cultivar doyenne du comice

Feed with fertilisers that contain large amounts of potash and phosphate but minimal nitrogen. This encourages vigorous root growth. Sprinkling compost or farmyard manure around the tree helps retain soil moisture.

Climate change is having significant deleterious impacts on all members of the Rosaceae family, including apples and pears. Australian studies indicate that temperatures are reaching higher than the evolutionary maximum for these species.

This stresses the plants. It adversely affects their health and performance and reduces their ability to store carbon and produce fruit crops.

The pear scab Venturia pirina

Levels of pest and disease infections are increasing. In particular, sap-sucking woolly aphids (Eriosoma lanigerum) have increased from minor to major apple pests in the last decade. Pear scab Venturia pirina has become a major cause of defoliation.

Chemical control options for both are limited, but regular drenching sprays with seaweed extracts may reduce their impact. Seaweed extracts additionally provide some foliar absorbed nutrients and increase the visual quality of fruit.

Professor Geoff Dixon is author of Garden practices and their science, published by Routledge 2019.

Which species can you plant to increase the nutrients in your soil and boost biodiversity, and which pathogen tackles some of those pesky weeds? Our resident gardening expert, Professor Geoff Dixon, tells us more.

The term ‘sustainability’ for gardening means replacing what you take out of the soil and supporting localised biodiversity. Harvested crops, for example, take out nutrients and water from the soil. Replacements should be supplied that aid biodiversity and have minimal impact, or zero impact, on climate change.

Seaweed (Ascophyllum) has been recognised as a valuable fertiliser source in British coastal areas for centuries. Now, proprietary seaweed extracts are gaining popularity either when applied directly as liquid feeds or sprays, or when added into composts.

Classed as biostimulants, seaweed extracts contain several micro-nutrients and a range of valuable plant stimulatory growth regulators. They encourage pest and disease tolerance, increase frost tolerance, stimulate germination, increase robust growth, and add polish to fruit such as apples and pears.

Seaweed bolsters some of the nutrients lost through gardening. Image from Geoff Dixon.

Benefits of borage

Some plants are very effective supporters of biodiversity. Borage (Borago officinalis), known also as starflower or bugloss, is a robust annual plant of Mediterranean origin with pollinator-attractive blue flowers.

It is very drought resistant and suitable for dry gardens. Although an annual, it is self-seeding and could spread widely. It is very attractive to bees as it produces copious light – and delicately flavoured honey.

Its flowers and foliage are edible with a cucumber-like flavour, making it suitable in salads and as garnishes, while in Germany it is served as grűne soße (green sauce). When used as a companion plant for crops such as legumes or brassicas, it will also help to suppress weeds.

Borage is good for bee and belly. Image from Geoff Dixon.

Weeding out the problem

Weeds are a continuous problem for gardeners and their prevalence varies with the seasons. Groundsel (Senecio vulgaris), also known as ‘old man in the spring’, persists whatever the weather.

It is ephemeral but can seed and regrow several times per year. As a result, once established, it is difficult to control without very diligent hand weeding and hoeing out young seedlings before the flowers form.

There is, however, a form of biological control that can aid the gardener. Groundsel is susceptible to the fungal rust pathogen (Puccinia lagenophorae). This pathogen arrived in Great Britain from Australia in the early 1960s. Since then, it has become well established and outbreaks on groundsel start to become obvious in mid- to late-summer, especially in warm dry periods.

A fungal pathogen can kill groundsel, a weed that comes through several times a year. Image from Geoff Dixon.

Severe infections weaken, and eventually kill, groundsel plants. Gardeners should take advantage of the infection and remove the diseased weeds before any seeds are produced.

>> How else has climate change changed the way our gardens grow, and what can be done to alleviate its effects? Geoff Dixon investigates.

Professor Geoff Dixon is author of Garden practices and their science, published by Routledge 2019.

Written by Professor Geoff Dixon. You can find more of his work here.

Image by Damien Walmsley.  

The Commonwealth Games has landed in Birmingham. Before the Games began, viewers were treated to an extraordinary opening ceremony (featuring a giant mechanical bull) and its artistic director, Iqbal Khan, was lauded for his ingenuity.

But such ingenuity shouldn’t surprise any of us, for Birmingham has long been a place of outsized invention. For more than 300 years, the inhabitants of this industrial powerhouse have churned out invention after invention; and its great pragmatists have turned patents into products.

Chemistry, too, owes a debt to the UK’s second city. Whether it’s the first synthesis of vitamin C, the invention of human-made plastic, adventures in mass spectrometry, or electroplated gold and silver trinkets, Birmingham has left a lasting legacy.

Here are five chemists whose innovations may have made an appearance in your life.

Alexander Parkes – man of plastic

Plaque commemorating Alexander Parkes in Birmingham, England. Image by Oosoom

Look around you. Look at the computer screen, the mouse button you click, and the wire casings everywhere. Someone started it all. That man was Alexander Parkes, inventor of the first human-made plastic.

The son of a brass lock manufacturer from Suffolk Street, Birmingham, Parkes created 66 patents in his lifetime including a process for electroplating delicate works of art. However, none were as influential as the 1856 patent for Parkesine – the world’s first thermoplastic.

Parkes’ celluloid was based on nitrocellulose that had been treated by different solvents. In 1866, he set up the Parkesine Company at Hackney Wick, London, but it floundered due to high cost and quality issues. The spoils of his genius would be enjoyed by the rest of us instead.

Sir Norman Haworth – the vitamin seer

Sir Norman Haworth

Sir Norman Haworth may have been born in Chorley, Lancashire, but his finest work arguably came after he became Director of the Department of Chemistry in the University of Birmingham in 1925. Haworth is famous for his groundbreaking carbohydrate investigations and for being the first to synthesise vitamin C.

By 1928, Haworth had confirmed the structures of maltose, cellobiose, lactose, and the glucoside ring structure of normal sugars, among other structures. Apparently, his method for determining the chain length in methylated polysaccharides also helped confirm the basic features of starch, cellulose, and glycogen molecules.

However, Haworth is most famous for determining the structure of vitamin C and for becoming the first to synthesise it in 1932. The synthesis of what he called ascorbic acid made the commercial production of vitamin C far cheaper – the benefits of which have been felt by millions of us.

For his achievements in carbohydrates and vitamin C, Haworth received the Nobel Prize for Chemistry in 1937 (shared with Paul Karrer). He was the first British organic chemist from the UK to receive this honour. Haworth even had a link to SCI, having been a pupil of William Henry Perkin Junior in the University of Manchester’s Chemistry Department.

Francis William Aston – adventures in mass spectrometry

Blue plaque for Francis William Aston. Image from Tony Hisgett

Another Nobel Prize-winning chemist from Birmingham is Francis William Aston. The Harborne native won the 1922 prize for discovering isotopes in many non-radioactive elements (using his mass spectrograph) and for enunciating the whole number rule.

For a time, academia almost lost Aston, as he spent three years working as a chemist for a brewery. Thankfully, he returned to academic life and obtained concrete evidence for the existence of two isotopes of the inert gas neon before the first World War.

After working for the Royal Aircraft Establishment during the Great War (1914-18), he resumed his studies. The invention of the mass spectrograph proved pivotal to his discoveries thereafter. Using this apparatus, he identified 212 naturally occurring isotopes.

George Elkington and John Wright – all that glitters

George Elkington patented the electroplating process developed by John Wright. Image from Spudgun67

It isn’t surprising that George Elkington should become an SCI favourite, as he blended both scientific ingenuity with business. The son of a spectacle manufacturer patented the first commercial electroplating process invented by Brummie surgeon John Wright in 1840.

Wright discovered that a solution of silver in potassium cyanide was useful for electroplating metals. Elkington and his cousin Henry purchased and patented Wright’s process before using it to improve gold and silver plating.

The Elkingtons opened an electroplating works in the city’s now famous Jewellery Quarter where they electroplated cutlery and jewellery. And they didn’t do too badly out of it. By 1880, the company employed 1,000 people in seven factories.

Alfred Bird – winging it

1906 advertisement for Birds Custard powder. Image from janwillemsen

In 1837, Alfred Bird was in a pickle. He wanted to serve his dinner party guests custard, but his wife was allergic to eggs and yeast, and egg was the main thickening agent of this delicious gloop.

Instead of serving something else, the chemist shop owner invented his own egg-free custard by substituting cornflour for eggs. His guests found it delicious and Bird’s Custard was born.

Not content with this innovation, Bird is also credited with being the father of modern baking powder. Once again, his wife’s allergies were said to be the inspiration, as he wanted to create a yeast-free bread for her. In bread and custard, true love always finds a way.

In his winning essay in SCI Scotland’s Postgraduate Researcher competition, Angus McLuskie, Postgraduate Researcher at the University of St Andrews, explains his work in replacing non-renewable and toxic feedstocks with novel sustainable catalytic processes to produce useful chemicals.

Each year, SCI’s Scotland Regional Group runs the Scotland Postgraduate Researcher Competition to celebrate the work of research students working in scientific research in Scottish universities.

This year, four students produced outstanding essays in which they describe their research projects and the need for them. In the first of this year’s winning essays, Angus McLuskie outlines his work in improving the production of urea derivatives and polyureas.

Would you risk your life for plastics and agrochemicals? You might not have to…

Urea derivatives hold a substantial global market, which is dominated by their use as fertilisers in the agrochemical sector, in addition to smaller-scale technical applications as glues, resin precursors, dyes and pharmaceutical drugs. Furthermore, polyureas are important protective coatings, with a global market exceeding £800 million a year.

Currently, urea derivatives and polyureas are produced on an industrial scale using highly toxic chemicals such as phosgene, (di)isocyanates and carbon monoxide. These reagents are detrimental to human health, as evidenced by the release of methyl isocyanate gas from the Bhopal Union Carbide factory in 1984, which led to thousands of deaths and a global outcry.

Phosgene was itself used as a battlefield chemical weapon in World War I, and is sourced from fossil-fuel-derived carbon monoxide. The result is a process with significant health and environmental impacts.

As part of a global drive to tackle climate change and move towards a circular economy, the objective of our research is to replace non-renewable and toxic feedstocks with novel sustainable catalytic processes to produce useful chemicals and materials.

>> More information about the Scottish Postgraduate Researcher competition.

In pursuit of greener methods, we have recently discovered synthetic methodologies, using a catalyst of manganese, to couple dehydrogenatively (1) methanol and (di)amines and (2) formamides and amines to make symmetrical (poly)ureas and unsymmetrical urea derivatives respectively (ACS Catal., DOI:10.1021/acscatal.2c00850).

Angus with his poster on Mn-Catalysed Dehydrogenative Synthesis of Urea Derivatives and Polyureas.

The only process byproduct, molecular hydrogen, is valuable in itself, and the non-toxic reagents of methanol or formamide can be sourced from renewable feedstocks. For example, Carbon Recycling International, an Iceland-based company, has developed methods to generate methanol industrially through the direct hydrogenation of CO2 (ATZextra Worldw., DOI:10.1007/S40111-015-0517-0). Formamides can be made from formic acid, which may be produced from biomass or CO2.

Synthesis approach

The synthesis of urea derivatives using this approach has been reported previously using iron and ruthenium catalysts, but these present individual limitations. Iron catalysts result in poor yields and substrate scope, while ruthenium catalysts are expensive and raise sustainability concerns due to ruthenium’s low abundance in Earth’s crust (Chem. Sci. J., doi.org/10.1039/C8SC00775F and Org. Lett., doi.org/10.1021/acs.orglett.5b03328).

The synthesis of polyureas via this approach has only been achieved before using a ruthenium catalyst. With a manganese-based pincer catalyst, we succeeded in making a broad variety of symmetrical and unsymmetrical urea derivatives as well as polyureas at high yields and under a low catalytic loading of 0.5-1 mol%. As the third most abundant transition metal in Earth’s crust, manganese is much cheaper than ruthenium, which improves the economic viability of the process for industrial applications.

Breaking new ground?

This is the first example of the synthesis of polyureas from diamines and methanol using a catalyst of an Earth-abundant metal. We have demonstrated for the first time the synthesis of a potentially 100% renewable polyurea from methanol and a renewable diamine Priamine, which is commercialised by Croda. This could be of interest to emerging businesses for making bio/renewable plastics.

Angus hopes his research will help us develop urea-functionalised agrochemicals and pharmaceutical drugs in a more efficient, greener way.

This initial proof of concept is exciting, but there are challenges to overcome for commercialisation. Evidently, the cost is important, and since the catalyst is much more expensive than reactants, such as amines and methanol, the cost is directly linked to the catalyst’s activity; a homogeneous catalyst that is non-recyclable and offers a turnover number of 100-200 makes the process expensive.

We are now focusing our efforts on enhancing the efficiency of the catalyst to increase cost-effectiveness, which will also allow us to make commercially important urea-functionalised pharmaceutical drugs and agrochemicals with greater efficiency and reduced impact on the environment, human health, and economy.

>> Interested in joining the SCI Scotland Group?

The wild weather fluctuations wrought by climate change are stressing out our plants. Our resident gardening expert, Professor Geoff Dixon, explains how.

Pests and diseases are familiar causes of plant damage and loss. Less familiar, but becoming more frequent, are stresses resulting from environmental causes.

These are termed abiotic stresses because no living organism is involved. This means there are no visible signs of pests or pathogens. Diagnosis and treatment are, therefore, less straightforward. These causes are a result of interactions between the plant genotype and the prevailing or changing environment.

Damage may only become apparent after harvesting and at the point of consumer use. A typical example of this is internal browning or breakdown of Brussels sprouts. Larger sprouts are more susceptible to stress, with dense leaf packing in the bud, particularly in early and midseason cultivars.

The internal browning of Brussels sprouts is a consequence of plant stress.

A suggested cause is water condensing within the bud, which restricts calcium transport and leads to marginal leaf necrosis (death). This resembles the exudation, or perspiration, of water from leaf edges when growing plants absorb excessive water, flooding the vascular systems following very heavy rainfall and hot weather.

Moisture damage

Oedema is another moisture-induced disorder. Symptoms include unattractive wart-like swellings coalescing on leaves and stems, particularly on Brussels sprouts, cabbages, and cauliflowers. These may rupture, becoming corky with a yellowish or brownish appearance.

Moisture-induced damage to cabbage leaves.

These symptoms result from high soil moisture content and high relative humidity associated with hot days and cool nights. Both internal browning and oedema can be minimised by improving soil structure, encouraging rapid drainage by deep cultivation or growing plants on raised beds.

Improving soil structure is becoming an important way to control salt accumulation. Soil structure can be badly damaged by flooding that brings in polluted water. In subsequent vegetable and fruit crops, plant water uptake, nutrient use efficiency, and photosynthesis are all impaired. The effects are seen in poor germination, burnt leaf margin, stunting, and wilting. This damage will be particularly severe with highly organic soils.

Salt accumulation in onion crops. Improving soil structure is one way of addressing this problem.

Abiotic disorders are becoming more common in commercial crops and this is likely to be reflected in gardens and allotments. That is an effect of climatic change, with generally hotter and wetter conditions interspersed by droughts and freezing events.

As a result, plant growth is erratic and exhibits abiotic disorders. Plant breeders, especially in Asia, are actively seeking genetic solutions that will create crops capable of withstanding erratic environments. In parallel,the agro-chemical industry is producing environmentally sustainable compounds and biostimulants to help combat these problems.

>> How else has climate change changed the way our gardens grow, and what can be done to alleviate its effects? Geoff Dixon explored this issue further.

Professor Geoff Dixon is author of Garden practices and their science, published by Routledge 2019.

What is so special about rainbow chard pigments, and what does this tasty plant have in common with cacti? The SCI Horticulture Group explains all, ahead of their appearance at BBC Gardeners’ World Live in Birmingham from 16-19 June.

The origins of chard

Chard (Beta vulgaris, subspecies vulgaris) is a member of the beetroot family and is grown for its edible leaf blades and leaf stems. Chard, sugar beet, spinach and beetroot have all been domesticated from the same wild ancestor species – sea beet (Beta vulgaris, subspecies maritima). Another food crop from the same botanical family is quinoa.

The term chard comes from the 14th century French word carde, which means artichoke thistle.

Nutritional properties

Chard's leaves are a valuable source of mineral nutrients, with a normal serving of 100g containing: 24% of our daily magnesium needs, 17% of iron, 16% of manganese, and 12% of both potassium and sodium. The same portion can provide 22% of our daily vitamin C needs, 13% of vitamin E, and 100% of our vitamin K.

>> What gives chillis their heat? The SCI Horticulture group has explored the weird and wonderful world of chillis.

The edible petioles (leaf stems) of Swiss chard are typically white, yellow, or red. Lucullus and fordhook giant are cultivars with white petioles. Canary yellow has yellow petioles and red-ribbed forms include ruby chard and rhubarb chard. Rainbow chard is a mix of coloured varieties, often mistaken for a variety unto itself.

The pigments that produce these colours belong to a special group – known as the betalains. These pigments are found only in species of one small section of the plant kingdom called caryophyllales. The pigments in the rest of the plant kingdom have different chemical structures, made up of only carbon, hydrogen and oxygen, whereas the betalain chemical structures also contain nitrogen.

Rainbow chard contains betalains, as do cacti, pokeweed, and (above) bougainvillea.

The many uses of chard pigments

The colourful pigments in plants not only contribute to the beauty of our gardens – they advertise the presence of flowers to pollinators or fruits to dispersal agents. Others deter herbivores by tasting bitter or act as a sunscreen to protect from strong ultraviolet light.

The vivid pigments found in chard are particularly useful. Betanin is the best-known pigment from this group and gives rise to the striking colour of beetroot. It is used commercially as a natural food dye, can help preserve food, and contains antioxidant properties.

Betanin, the pigment that makes beetroot (and poop) red.

Some people are unable to metabolise betanin, which gives rise to a phenomenon known as beeturia – where human waste is coloured red by the betanin.

Cooking with chard

When cooking with chard, it can be treated as two separate vegetables – the leafy part and the crunchy petiole. Blitva is a traditional Croatian dish made from the leafy part, often cooked along with potatoes and served with fish.

Blitva is made with chard, potato, olive oil, and garlic.

Chard stalks sautéed with lemon and garlic forms another popular side-dish, while lovers of Italian cuisine can turn rainbow chard into a pesto with pine nuts, parmesan and basil.

Find us at BBC Gardeners’ World Live

From 16-19 June, the SCI Horticulture Group will tell the public all about the hidden chemistry behind their favourite fruit and vegetable plants at the National Exhibition Centre in Birmingham for BBC Gardeners’ World Live. If you’re curious to learn all about rainbow chard, chillis, and strawberries, pop by and say hello!.

>> Written by the SCI Horticulture Group and edited by Eoin Redahan. Special thanks to Neal Price from Chillibobs, Martin Peacock of ZimmerPeacock, Hydroveg, and The University of Reading Soft Fruit Technology Group for supporting the work of the SCI Horticulture Committee at BBC Gardeners’ World Live.

>> The SCI Horticulture Group brings together those working on the wonderful world of plants.

Which molecules give strawberries their distinctive smell, how are experts using different types of light to grow them all year round, and just how many of them do we eat? The SCI Horticulture Group told us all about this beloved fruit ahead of their appearance at BBC Gardeners’ World Live in Birmingham from 16-19 June.

Where did strawberries originate?

The woodland strawberry (Fragaria vesca) was first cultivated in the 17th century, but the strawberry you know and love today (Fragaria x ananassa) is actually a hybrid species. It was first bred in Brittany, France, in the 1750s by cross-breeding the North American Fragaria virginiana with the Chilean Fragaria chiloensis.

The strawberry is a member of the rose family, as are many other popular edible fruits such as apples, pears, peaches, and plums. It is the most commonly consumed berry crop worldwide.

People in the UK consume an average 3kg of strawberries every year. Perhaps a certain sporting event has something to do with it…

How many do we eat?

A staggering 9 million tonnes of strawberries are produced globally each year, and their popularity certainly extends to UK shores, and not just during Wimbledon. In the UK alone, the average per capita consumption of strawberries is about 3kg a year!

Domestic strawberry production provides almost all the required fruit for the UK market from March to November; and in 2020, 123,000 tonnes of strawberries were produced within the UK.

This stands in stark contrast to the 50,000 tonnes produced in 1985, when UK strawberries were only produced during June and July. Researchers are currently trying to extend the UK growing season to all year round.

She certainly likes the smell of strawberries, but what gives them that distinctive aroma?

What about the chemistry of their distinctive smell?

The characteristic strawberry aroma consists of many different volatile organic chemicals – more than 360 have been observed in fresh strawberries. Which molecules are present, and in what concentrations, depends on the particular cultivar and how mature or ripe it is.

The most common kinds of chemical are furanones and esters. Esters (such as methyl butanoate) account for more than one third of the observed molecules and 25–90% of the volatiles from any one cultivar.

These molecules are responsible for the fruity and floral notes of the aroma. The most characteristic furanone that gives rise to the characteristic strawberry odour is DMHF.

Pictures like this only increase demand for strawberries out of season.

How to produce strawberries all year...

To optimise strawberry growing conditions, researchers are investigating the influence of temperature, photo-period (response to daily, seasonal, or yearly changes in light and darkness), growth hormones, night-break lighting and CO2 enrichment on flowering and fruiting timing, yield, and quality.

Optimal chilling models are also being developed for both June-bearers and ever-bearers. Critically, a careful and detailed evaluation of the environmental and economic costs of producing winter UK strawberries compared to imports is being undertaken.

Extending the growing season in the UK would have a number of benefits, such as; meeting the increasing demand for out-of-season strawberries while increasing food security, reducing food miles, contributing to public health, providing continued employment, and supporting sustainable farming.

>> Are you a keen gardener? Our resident gardening expert, Geoff Dixon, provides plenty of gardening tips for you on the SCIBlog.

Improving the fruit's nutrient profile

The nutrient content of strawberries is dependent in part on the plant’s growing conditions. The interaction between light intensity and root-zone water deficit stress is being examined to improve berry nutrient content. Researchers are also investigating how to apply this to commercial strawberry production in total environment-controlled agriculture systems.

See how a college in Finland is harnessing LEDs to power a vertical strawberry farm!

LED light colour and strawberry growth

Light emitting diode (LED) lighting increases yields in out-of-season strawberry production. LEDs have a higher energy efficiency than traditional horticultural lighting and come in a range of single colours with varying efficiencies and effects on plant growth.

Red LEDs convert energy into light (and drive photosynthesis) most efficiently, followed by blue, green, and far-red, respectively. However, red light alone is not sufficient for optimum plant growth. Blue light controls flowering, promotes stomatal opening (pores found in various parts of the plant), inhibits stem elongation, and increases secondary metabolites (organic compounds produced by the plant), thereby improving flavour.

Additional green LEDs, which appear white, improve visibility for workers. These lights can also penetrate deeper into the plant canopy, improving photosynthesis. Far-red light produces shade avoidance responses such as canopy expansion and earlier flowering, which can be beneficial for increased light capture and earlier fruiting.

Confirmed strawberry.

Who is carrying out strawberry research in the UK?

The Soft Fruit Technology Group at the University of Reading is just one of the institutions providing research to support the UK strawberry industry. The main areas of research are plant propagation, crop management, and production systems.

Find us at BBC Gardeners’ World Live

From 16-19 June, the SCI Horticulture Group will tell the public all about the hidden chemistry behind their favourite fruit and vegetable plants at the National Exhibition Centre in Birmingham for BBC Gardeners’ World Live. If you’re curious to learn all about strawberries, chillis, and chard, pop by and say hello!

>> Written by The SCI Horticulture Group. Special thanks to Neal Price from Chillibobs, Martin Peacock of ZimmerPeacock, Hydroveg, and The University of Reading Soft Fruit Technology Group for supporting the work of the SCI Horticulture Committee at BBC Gardeners’ World Live.

What makes chilli peppers so spicy and how do they help with pain relief? The SCI Horticulture Group explained all ahead of their appearance at BBC Gardeners’ World Live in Birmingham from 16-19 June.

This June, the SCI Horticulture Group will tell the public all about the hidden chemistry behind their favourite fruit and vegetable plants. One of the main plants they will feature at the National Exhibition Centre is the humble chilli pepper – and these famous fruit-berries conceal more secrets than you might think…

Where does the chilli originate?

The chilli pepper (Capsicum spp.) is a member of the Solanaceae, the plant family that includes edibles such as potatoes, tomatoes, aubergines, but also poisonous plants such as tobacco, mandrake, and deadly nightshade.

Who brought the chilli pepper to these shores?

The chilli was brought to Europe in the 15^th century by Christopher Columbus and his crew. They became acquainted with it on their travels in South and Central America and, shortly thereafter, to India via the Portuguese spice trade.

How varied is the genus?

Of the 42 species in the capsicum genus, five have been domesticated for culinary use. Capsicum annuum includes many common varieties such as bell (sweet) peppers, cayenne and jalapenos. Capsicum frutescens includes tabasco. Capsicum chinense includes the hottest peppers such as Scotch bonnet. Capsicum pubescens includes the South American rocoto peppers, and capsicum baccatum includes the South American aji peppers.

From the five domesticated species, humans have bred more than 3,000 different cultivars with much variation in colour and taste. The chilli and bell peppers that we eat are the fruit – technically berries – that result from self-pollination of the flowers.

>> The SCI Horticulture Group brings together those working on the wonderful world of plants.

And we eat a lot of them?

Today, chilli peppers are a global commodity. In 2019, 38 million tonnes of green chilli peppers were produced worldwide, with China producing half of the total. Spain is the largest commercial grower of chillies in Europe.

Capsaicin helps give chilli peppers their heat

What makes chillies hot?

Capsaicin is the main substance in chilli peppers that provides the spicy heat. It binds to receptors that detect and regulate heat (as well as being involved in the transmission and modulation of pain), hence the burning sensation that it causes in the mouth.

In humans, these receptors are present in the gut as well as the mouth (in fact, throughout the peripheral and central nervous systems) – hence the after-effects of eating too much chilli. Capsaicin, however, is not equally distributed in all parts of pepper fruit. Its concentration is higher in the area surrounding the seeds.

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How do you measure chilli heat?

The Scoville Heat Unit Scale is used to classify the strength of chilli peppers. Scoville heat units (SHU) were named after American pharmacist Wilbur Scoville who devised a method for rating chilli heat in 1912.

The ludicrously hot Dragon’s Breath chilli

This method relied on a panel of tasters who diluted chilli extract with increasing amounts of sugar syrup until the heat became undetectable. The greater the dilution to render the sample’s heat undetectable, the higher the SHU rating. Pure capsaicin measures 16,000,000 SHU.

The capsaicin content of chilli peppers varies wildly, as is reflected in the SHUs of the peppers below:

1. Bell (Sweet peppers) = 0 SHU
2. Jalapeno = 5,000 SHU
3. Scotch Bonnet = 100,000 SHU
4. Naga Jolokia = 1,040,000 SHU
5. Carolina Reaper = 1,641,183 SHU
6. Dragon’s Breath = 2,480,000 SHU

Dispersal vs. protection – why do chillies contain capsaicin?

The seeds of chillies are dispersed in the wild by birds who do not have the same receptors as mammals and, therefore, are unaffected by capsaicin. Perhaps chillies have evolved to prevent mammals from dispersing their seeds?

Capsaicin has also been shown to protect the plant against fungal attack, thus helping the fruit to reach maturity and the seeds to be dispersed before succumbing to rot. This antifungal property can also be put to good use in helping to preserve foods for human consumption.

How did chilli help win a Nobel Prize?

Capsaicin was pivotal in the research that led to the award of the 2021 Nobel Prize in physiology and medicine to David Julius and Ardem Patapoutian for their discoveries of receptors for temperature and touch.

The two US-based scientists received the accolade for describing the mechanics of how humans perceive hot, cold, touch, and pressure through nerve impulses. The research explained at a molecular level how these stimuli are converted into nerve signals, but the starting point for the study was work with capsaicin from the humble chilli pepper.

Capsaicin in medicine

Capsaicin is used as an analgesic (a pain reliever) in topical ointments, nasal sprays, and patches to relieve chronic and neuropathic pain. Clinical trials continue to investigate the potential of capsaicin for a wide range of additional pain indications and as both an anti-cancer and anti-infective agent.

>> Special thanks to Neal Price from Chillibobs, Martin Peacock of ZimmerPeacock, Hydroveg, and The University of Reading Soft Fruit Technology Group for supporting the work of the SCI Horticulture Committee at BBC Gardeners’ World Live.

>> Our resident gardening expert, Geoff Dixon, provides plenty of gardening tips on the SCIBlog.

How do green spaces, gardens as well as fruit and vegetables impact our health and wellbeing? Professor Geoff Dixon tells us more.

‘We are what we eat’ is an aphorism that is becoming much better understood both by the general public and by healthcare professionals. Similarly, ‘we are where we live’ is gaining greater appreciation. Both these pithy observations underline the social and economic importance of horticulture and the allied art of gardening.

An exuberant display of flowers – what can be better for the soul?

Few things stimulate the human spirit more than a fine, colourful display of well grown and presented flowers. Seeing and working with green and colourful plants is increasingly recognised for its psychological power, reducing stress and increasing wellbeing. In our increasingly urbanised society, with myriads of high-rise housing blocks, the provision of well-tended parks and gardens is not a luxury – it is essential.

Hospital patients recover more quickly when they can see and sit in green spaces. Equally, providing access to gardens and gardening for schools should be a vital part of the children’s environment. They gain an understanding of biological mechanisms and the equally important need for conserving biodiversity and controlling the rate of climate change.

The recently published National Food Strategy emphasised the importance of fruit and vegetables as a major part of our diets. Both fruit and vegetables provide essential vitamins, nutrients and fibres which consumed over time diminish the incidence of cancers, coronary, strokes and digestive diseases.

Apricots are high in catechins.

Eating varying types of fruit and vegetables increases their value – apricots, for example, are high in catechins which are potent anti-inflammatory agents. Members of the brassica (cabbage) family are exceptionally valuable for mitigating diseases of ‘modern society’. All contain glucosynolates, which evolved as means for combating pest and pathogen attacks and co-incidentally provide similar services for humans. Watercress – an aquatic brassica – is rich in vitamins A, C and E, plus folate, calcium and iron. Its high water content means portions consumed fresh or as soups are low in calories.

Watercress – an aquatic brassica boasts numerous health benefits.

These messages and facts are now being recognised both publicly and politically, and not before time. For the past 50 years the universal panaceas have been pharmaceutical drugs. In moderation, these have been of immense value. Use to excess is both counterproductive and needlessly expensive health-wise and financially.

Returning to Grandma’s advice, ‘an apple a day keeps the doctor away’, supports both individual and planetary good health.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

There was a happening in York recently – a Hemp Happening – organised by SCI’s Agrisciences Group and Biovale. It took place at York’s STEM Centre and explored the issues around growing and using industrial hemp. Despite these issues, there is a growing demand for hemp fibre and shiv as we look to use sustainable natural fibres and move to a low-carbon economy.

In 10 years’ time, you’ll walk out of your hemp-insulated home, wearing your hemp fibre t-shirt, polishing off the last of your hemp and beet burger, before heading to work in your hemp seed oil-powered car.

Is this scenario fantastical? Yes, obviously, but as delegates attending Hemp Happening explained on 6 April, all of these products exist right now. The sheer breadth of them underlines what a useful and versatile material hemp is. If enabled through policy, hemp could play a big part in our low-carbon future. Here are five ways it could make a significant difference.

1. Carbon sequestration

Hemp has much-vaunted carbon-sequestering potential which, given our climate change travails, could prove extremely useful. Some experts say it is even better at capturing atmospheric carbon than trees. According to SAC Consulting, industrial hemp absorbs nine to 13 tonnes of CO₂ per hectare. To put hemp’s absorption capacity into context, hemp market specialists Unyte Hemp said it absorbs 25 times more CO₂ than a forest of the same size.

Of course, that’s all very well, but how do you make sure this carbon remains sequestered?

2. A future heavyweight champion?

One fitting home for hemp (and the carbon it has captured) is in construction, especially given the carbon-intensive nature of the industry. So, with the pressure intensifying to replace and retrofit the UK’s inefficient building stock, hemp is well placed to reduce emissions and improve building performance.

Hemp is not just used in insulation materials due to its excellent thermal performance characteristics. It is also used in rendering buildings and for non-load bearing blocks in construction. Indeed, hempcrete blocks, which are made from hemp shiv, lime, and sand or pozzolans, have a net carbon negative footprint.

Hemp is used in everything from food supplements to medicines, cosmetics, and construction products.

3. Farmer’s friend

Hemp also helps the earth. As flash flooding strips our soils, the plant’s root density and deep structure protects against soil erosion and mitigates compaction. Hemp also provides nutrients to help maintain soil health, making it useful in crop rotation.

As insect populations dwindle, the role of pesticides and herbicides are coming into sharper relief. In that respect, hemp has a natural advantage over other crops as it doesn’t require pesticides and fertilisers.

4.The Swiss Army knife of materials

We have long heard of the health benefits of hemp-derived products such as cannabidiol oil (or CBD oil), but pretty much the whole plant can be used. Its seeds are rich in omega-3, omega-6, and fatty acids, and help fend heart problems.

As mentioned above, the fibrous part of the plant sequesters carbon and produces low-carbon materials for construction, while its roots are used to treat joint pain and for deep tissue healing.

And then we have hemp for bioethanol production and even hemp seed veggie burgers. The list goes on; so, there are many ways for farmers to make money from it.

>> What can be done to make our soils healthier? Take a look at our blog on solving soil degradation.

Hemp has excellent insulation properties.

5. Non-thirsty textiles

I bet you know at least one person with a bamboo t-shirt or socks. Hemp has similar textile potential to its super material cousin. As the fashion industry interrogates its wayward past, the pressure will increase to lighten the footprint of clothing materials. Estimates vary, but hemp is said to need less than half the water required to cultivate and process than cotton textiles and its toughness is handy in long-lasting carpeting.

Mr Elephant, could you step through please?

Hemp has been heralded as a wonder material for decades but there is that elephant in the room. The restricted uses of hemp-related materials curb the extent to which it can be grown in the UK. At the event, delegates noted that outdated legislation, lack of government support, and education are among the factors holding back the growth of hemp on an industrial scale.

And yet, there is growing demand for natural materials that tackle climate change, especially those that sequester carbon. With pension funds increasingly divesting from fossil fuels, and the ever growing importance of corporate sustainability in business, sustainable materials such as hemp are now more attractive.

Arguably the most exciting contribution of the day was the mention of zero-cannabinoid industrial hemp. Even though the THC content levels present in hemp are low (compared to the high levels found in marijuana) and it’s unattractive as a THC source, hemp is still very strictly regulated in the UK compared to North America and the rest of the EU.

One participant mentioned that hemp genes could be edited to remove the cannabinoid – and, if that were to be achieved, it could change everything. Then we would really see hemp happening in the UK.

>> Interested in more events like this one? Visit our Events pages.

Crop rotation, seaweed extracts, lime, and a range of organic materials can all improve soil health and crop yields. Professor Geoff Dixon shows you several ways to improve your soil.

Rapidly rising costs of living are affecting all aspects of life. Increasing costs of fertilisers are affecting food production, both commercially and in gardens and allotments.

Wholesale prices of fertilisers have jumped four-fold from £250 to £1,000 per tonne within six months. All forms of garden fertilisers are now much more expensive. Crops, especially vegetables, only thrive if provided with adequate nutrition (see nitrogen-deficient lettuce below). Consequently, fertiliser use must become more efficient.

Nitrogen deficiency in lettuce.

Healthy, fertile soils achieved through good management are key to this process. That ensures roots can take up the nutrients needed in quantities that result in balanced, healthy growth.

Soil pH is a major regulator of nutrient availability for roots. Between pH 6.5 to 7.5, the macro nutrients, nitrogen, phosphorus, and potassium are fully available for root uptake. Below and above these values, nutrient absorption becomes less efficient.

>> How much soil cultivation do you need for your vegetables? Find out more in Prof Dixon's blog on cultivation.

As a result, soluble nutrients are wasted and washed by rainfall below the root zones. Acidic soils can be improved by liming in the autumn. Sources of lime derived from crushed limestone require up to six months to cause changes in soil pH values. Lime should be used in ornamental gardens with caution as it can result in micronutrient deficiencies.

Iron deficiency in wisteria.

Soil health and fertility are greatly increased by adding organic materials such as farmyard manure and well-made composts. Increasing soil carbon content helps mitigate climate change while raising fertiliser use efficiencies.

Beneficial soil biological life such as earthworms, insects, benign bacteria and fungi are greatly encouraged when you increase soil humus content. Using crop rotations, which include legumes, raises natural levels of soil nitrogen. This is a result of legumes’ symbiotic relationships with nitrogen-fixing bacteria.

Leafy vegetables such as brassicas require large amounts of nitrogen and, hence, should follow legumes in a rotation. Avoiding soil compaction encourages adequate aeration, benefiting root respiration and providing oxygen for other organisms.

Organic materials are of great value in ornamental gardens when applied as top dressings in late autumn or early spring. This provides two benefits: a slow release of nutrients into the root zones as decomposition occurs, and prevention of weed growth.

Inorganic fertiliser use can be further minimised by using proprietary seaweed extracts. These contain macro- and micro-nutrients plus several natural biostimulant compounds that aid healthy ornamental plant growth and flowering (illustration no 3 rose Frűhlingsgold).

Rose frűhlingsgold

Written by Professor Geoff Dixon, author of Garden practices and their science.

How do flowers use fragrance to attract pollinators, and how do pollution and climate change hamper pollination? Professor Geoff Dixon tells us more.

‘Fragrance is the music of flowers’, said Eleanour Sophy Sinclair Rohde, an eminent mid 20^th century horticulturist. But they are much more than that. Scents have fundamental biological purposes. Evolution has refined them as means for attracting pollinators and perpetuating the particular plant species emitting these scents.

There are complex biological networks connecting the scent producers and attracted pollinators within the prevailing environment. Plants flowering early in the year are generalist attractors. By late spring and early summer, scents attract more specialist pollinators as shown by studies of alpines growing in the USA Rocky Mountains. This is because there is a bigger diversity of pollinator activity as seasons advance. Scents are mixtures of volatile organic compounds with a prevalence of monoterpenes.

Environmental factors will affect scent emission. Natural drought, for example, changes flower development and reduces the volumes and intensity of scent production. The effectiveness of pollinating insects, such as bees, moths, hoverflies and butterflies is reduced by aerial pollution.

Pheasant’s eye daffodils (Narcissus recurvus).

Studies showed there were 70% fewer pollinators in fields affected by diesel fumes, resulting in lower seed production. Pollinating insects do not find the flowers because nitrogenous oxides and ozone change the composition of scent molecules.

Extensive studies of changes in flowering dates show that climate change can severely damage scent–pollinator ecologies. Over the past 30 years, blooming of spring flowers has advanced by at least four weeks. Earlier flowering disrupts the evolved natural synchrony between scent emitters and insect activity and their breeding cycles. In turn that breaks the reproductive cycles of early flowering wild herbs, shrubs and trees, eventually leading to their extinction.

The lilac bush, known for its evocative scent.

Heaven scent

Scents provide powerful mental and physical benefits for humankind. Pleasures are particularly valuable for those with disabilities especially those with impaired vision. Even modest gardens can provide scented pleasures.

Bulbs such as Pheasant’s eye daffodils (Narcissus recurvus) (illustration no 1), which flower in mid to late-spring, and lilacs (illustration no 2) are very rewarding scent sources.

Sweetly perfumed annuals such as mignonette, night-scented stocks, candytuft and sweet peas (illustration no 3) are easily grown from garden centre modules, providing pleasures until the first frosts.

Sweet peas are easily grown from garden centre modules.

Roses are, of course, the doyenne of garden scents. Currently, Harlow Carr’s scented garden, near Harrogate, highlights the cultivars Gertrude Jekyll, Lady Emma Hamilton and Saint Cecilia as particularly effective sources of perfume. For larger gardens, lime or linden trees (Tilia spp) form profuse greenish-white blossoms in mid-season, laden with scents that bees adore.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

The plant-based meat alternative market is growing rapidly, and cell-cultured meats could be coming soon to your dinner plate once they receive regulatory approval. Gavin Dundas, Patent Attorney at Reddie & Grose, provides his expert perspective on the state of the meat alternative market.

Which is receiving more emphasis based on patent activity: lab-grown meat or plant-based meat alternatives?

Comparing cultivated meat to plant-based meat is a bit like comparing apples and oranges.
Plant-based meat is here - it’s in shops, and it’s in growing numbers of restaurants and fast-food outlets. Even McDonald’s – arguably the world’s most well-known hamburger outlet – released its first plant-based burger in the UK on 13 October 2021: the aptly-named McPlant. The McPlant has been accredited as vegan by the Vegetarian Society, and includes vegan sauce, vegan cheese and a plant-based burger co-developed with Beyond Meat.

Cell-cultured meat is a very different prospect, as cellular agriculture is more high-tech, so companies entering that sector require a higher degree of specialised technical expertise. Companies delving into cultivated meat also require a fair bit of funding, as cultivated meat has not been approved for sale in any country other than Singapore, so it is not yet possible to sell their products to consumers.

The reality at the moment is that plant-based meat alternatives have a huge head-start in the marketplace, while cultivated meat is not yet on sale in most countries. So, for most new companies looking to make money in the alternative protein market, plant-based products are likely to be the easier way to start.

On the other hand, this means that the plant-based meat market is more crowded already, while cultivated meat companies are investing in the hope of getting a bigger share of that market once it matures.

In which food types have you seen a particular surge in patent applications, for example plant-based meat alternatives or lab-grown meat?

Based on searches using patent classification codes commonly used for plant-based meats and lab-grown meat (known as ‘cell-cultured meat’ or ‘cultivated meat’), it appears that there are significantly more patent applications in the field of plant-based meats, but that patent filings relating to cultivated meat are growing more quickly.

Of all the patent publications relating to plant-based meats, 15.2% were published since the start of 2020. Of the patent publications relating to cultivated meats, 27.6% were published since the start of 2020.

This outcome is probably not surprising. Plant-based meats have been around much longer and are now widely established in the market, so many more companies have had time and opportunity to file patent applications for innovations in this area. Cultivated meats are at an earlier stage in their development, but with a large number of new companies having been formed in this area in the last few years, it is not surprising that this has resulted in a high growth rate of patent applications as cultivated meat gets closer to commercial reality.

Beyond Meat’s plant-based meat substitutes have reached the mainstream. | Jonathan Weiss/Shutterstock

How much movement has there been on the equipment and other innovations that will facilitate large-scale meal alternative manufacturing?

There is a huge difference between small-scale production of cultivated meat in a laboratory, and the large-scale manufacturing that would be needed to supply supermarkets and restaurants throughout whole countries and - eventually - the whole world.

Growing meat using cellular agriculture involves the use of animal cell lines to grow animal products in bioreactors, where the cells are immersed in a growth medium that feeds nutrients to the cells as they develop. Over the last decade there have been huge advances in these processes, but as demand for cultivated meat grows there will definitely be continued innovation to improve efficiency and scale-up manufacturing capacity.

Commercial growth medium is currently costly, so the development of more cost-effective growth media is likely to be an area of much research. Another ongoing challenge is the development of high-quality cell lines and scaffold materials that are suitable for high-quality, large-scale production.

Bioreactor design is also expected to be a big area of innovation - up until now, bench-top bioreactors have in most cases been sufficient to meet the demands of cultivated meat R&D, but as demand increases bigger and better bioreactors will be needed. A particular challenge will be to design bioreactors capable of growing thick tissue layers on a commercially viable scale.

While there is scope for innovation in all of these areas, some companies are already ready to manufacture their cultivated meat products on a large scale. Future Meat Technologies, for example, opened its first industrial cultivated meat production facility in June 2021 in Rehovot, Israel - that facility is reportedly capable of producing 500kg of cultivated meat products every day. In November 2021, Upside Foods opened its first large-scale cultivated meat production plant in Emeryville, California, with the capacity to produce 22,680kg of cultured meat annually.

At the moment, however, a lack of regulatory approval is holding back cultivated meat production. While there are a number of companies that apparently have products ready for market, many will be unwilling to plough huge amounts of money into large-scale manufacturing facilities until they have regulatory approval that lets them actually sell their products.

Thinking of filing a chemistry patent in 2022? Here’s what you need to know.

The UK has cutting-edge companies in the cultivated meat field.

Have any innovations or areas of innovation struck you as particularly exciting? If so, could you tell us more about them?

I am a meat-eater trying to cut down on my consumption of meat, due to a mixture of environmental and ethical motivations. So, as a consumer I’ve been very excited to see the arrival of plant-based meat into the mainstream.

I am particularly excited to try cultivated meat once it is approved for sale. Not long ago ‘lab-grown’ meat seemed like science-fiction, so to get to a point where you can go out and buy it will be incredible. So many people are unwilling to cut down on meat because they like the taste, and because their favourite meals are meat-based, so cultivated meat might hopefully give that same experience with fewer of the drawbacks of animal meat.

I am also excited to see the diversity of cultivated meat products. Cultivated meat chicken nuggets and beef burgers are the products that spring to mind when cell-cultured meat is mentioned, but there are companies out there developing cultivated bacon, pork belly, salmon and tuna, to name a few.

What are the chemistry challenges for those creating plant-based meat alternatives? Find out here.

Given what you know about the patent landscape, where do you think the meat alternative industry is heading, and at what sort of pace do you foresee significant change?

I think the meat alternative industry is only going to continue to grow, as concern over the environmental impact of our eating habits is growing, and the quality and availability of meat alternatives is getting better.

The plant-based meat industry is already doing well, and I expect it to continue on its upward trajectory. I expect companies in this field to continue to file patent applications for their innovations, and eventually we might see some of those patents being enforced to safeguard valuable market shares for the patent owners.

Cultivated meat is the sector that seems to be poised for the most significant change. At the moment, the lack of regulatory approval seems to be the thing holding it back, but if that hurdle is removed there are UK companies aiming to get cultivated meats into shops by 2023. The UK is lucky enough to be home to a number of cutting-edge companies in the field, and a recent report by Oxford Economics researchers forecast that cultivated meat could be worth £2.1 billion to the UK economy by 2030.

The idea of cultivated meat is unlikely to appeal to everyone, so I imagine that it will start out as something of a novelty, but I’d expect to see the availability and range of cultivated meat products grow significantly over the next decade.

Edited by Eoin Redahan. You can read more of his work here.

How much soil cultivation do you need for your vegetables? Professor Geoff Dixon explains all.

Cultivating soil is as old as horticulture itself. Basically, three processes have evolved over time. Primary cultivation involves inversion which buries weeds, adds organic matter and breaks up the soil profile, encouraging aeration and avoiding waterlogging.

Secondary cultivation prepares a fine tilth as a bed for sowing small seeded crops such as carrots or beetroot. In the growing season, tertiary cultivation maintains weed control, preventing competition for resources (illustration no. 1) such as light, nutrients and water while discouraging pest and disease damage.

Lettuce and seed competition

The onset of rapid climate change encouraged by industrialisation has focused attention on preventing the release of carbon dioxide into the atmosphere. Ploughing disturbs the soil profile and accelerates the loss of carbon dioxide from soil.

It is also an energy intensive process. Consequently, many broad acre agricultural crops such as cereals, oilseed rape and sugar beet are now drilled directly without previous primary cultivation. An added advantage is that stubble from previous crops remains in situ over winter, offering food sources for birds. The disadvantages of direct drilling are: increased likelihood of soil waterlogging and reduced opportunities for building organic fertility by adding farmyard manure or well-made composts.

Overall, primary and secondary cultivation benefit vegetable growing. The areas of land involved are far smaller and the crops are grown very intensively. Vegetables require high fertility, weed-free soil, good drainage and minimal accumulation of soil-borne pests and diseases.

Frost action breaking down soil clods

Digging increases each of these benefits and provides healthy physical exercise and mental stimulation. Frost action on well-dug soil breaks down the clods (illustration no. 2). Ultimately, fine seed beds are produced by secondary cultivation (illustration no. 3), which encourage rapid germination and even growth of root and salad crops.

Tertiary cultivation to prevent weed competition is also of paramount importance for vegetable crops. Competition in their early growth stages weakens the quality of root and leafy vegetables, destroying much of their dietary value. Regular hoeing and hand removal of weeds are necessities in the vegetable garden.

Raking down soil producing a fine tilth

Ornamental and fruit gardens similarly benefit from tertiary cultivation. Weeds not only provide competition but are also unsightly, destroying the visual image and psychological satisfaction of these areas.

Lightly forking over these areas in spring and autumn encourages water percolation and root aeration. Once established, ornamental herbaceous perennials and soft and top fruit areas benefit greatly from the addition of organic top dressings. Over several seasons these will augment fertility and nutrient availability.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

A sprig of thyme to fight that cold… Turmeric tea after exercising… An infusion of chamomile to ease the mind… As we move with fresh resolution through January, Dr Vivien Rolfe, of Pukka Herbs, explains how a few readily available herbs could boost your health and wellbeing.

The New Year is a time when many of us become more health conscious. Our bodies have been through so much over the last few years with Covid, and some of us may need help to combat the January blues. So, can herbs and spices give us added support and help us get the new year off to a flying start?

The oils in chamomile have nerve calming effects.

Chamomile and lavender

We may wish to ease ourselves into the year and look for herbs to help us relax. The flowers from these herbs contain aromatic essential oils such as linalool from lavender (Lavandula) and chamazulene from German chamomile (Matricaria recutita) that soothe us when we inhale them (López et al 2017). Chamomile also contains flavonoids that are helpful when ingested (McKay & Blumberg 2006).

If you have a spot to grow chamomile in your garden, you can collect and dry the flowers for winter use. Lavender is also a staple in every garden and the flowers can be dried and stored. Fresh or dry, these herbs can be steeped in hot water to make an infusion or tea and enjoyed. As López suggests, the oils exert nerve calming effects. Maybe combine a tea with some breathing exercises to relax yourselves before bed or during stressful moments in the day.

Thyme is a handy herbal remedy. Generally, the term herb refers to the stem, leaf and flower parts, and spice refers to roots and seeds.

>> The plant burgers are coming. Read here about the massive growth of meat alternatives.

Andrographis, green tea and thyme

Many people may experience seasonal colds throughout the winter months and there are different herbal approaches to fighting infection. Andrographis paniculata is used in Indian and traditional Chinese medicine and contains bitter-tasting andrographolides, and in a systematic review of products, the herb was shown to relieve cough and sore throats symptoms in upper respiratory tract infection (Hu et al 2017).

Gargling with herbal teas is another way to relieve a sore throat, and the benefits of green tea (Camellia sinensis) have been explored (Ide et al 2016). I’m an advocate of garden thyme (Thymus vulgaris) which contains the essential oil thymol and is used traditionally to loosen mucus alongside its other cold-fighting properties.

You could experiment by combining thyme with honey to make a winter brew. I usually take a herbal preparation at the sign of the very first sneeze that hopefully then stops the infection progressing.

Shatavari and ashwagandha

We may start the new year with more of a spring in our step and wishing to get a little fitter. As we get older, we may lose muscle tissue which weakens our bones and reduces our exercise capability. Human studies have found that daily supplementation with shatavari (Asparagus racemosus) can improve strength in older women, and ashwagandha (Withania somnifera) can enhance muscle strength and recovery in younger males (O’Leary et al 2021; Wankhede et al 2015).

These herbs are known as adaptogens and traditionally they are used in tonics or to support fertility. The research to fully understand their adaptogenic activity or effects on muscle function is at an early stage. Other herbs such as turmeric may help muscle recovery after exercise. I brew a turmeric tea and put it in my water bottle when I go to the gym.

>> How is climate change affecting your garden? Find out here.

Easy on the body. Easing the mind

Depending on your resolutions, you could use herbs and spices to add lovely flavours to food to try and reduce your sugar and salt intake. Liquorice is a natural sweetener, and black pepper and other herbs and spices can replace salt.

You could also bring joy to January by growing herbs from seed on a windowsill or in a garden or community space. Mint, lemon balm, lavender, thyme, and sage are all easy to grow, although mint and balm may take over!

All make lovely teas or can be dried and stored for use, and research is also showing that connecting with nature – even plants in our homes – is good for us.

You can read more about medicinal and culinary properties of herbs at https://www.jekkas.com/.

If you wish to learn more about the practice of herbal medicine and the supporting science, go to https://www.herbalreality.com/.

>> Dr Viv Rolfe is head of herbal research at Pukka Herbs Ltd. You can find out more about Pukka’s research at https://www.pukkaherbs.com/us/en/wellbeing-articles/introducing-pukkas-herbal-research.html, and you can follow her and Pukka on Twitter @vivienrolfe, @PukkaHerbs.

Edited by Eoin Redahan. You can find more of his work here.

Greenhouse gas emissions statistics can be misleading. At a recent SCI webinar on the Future of Agriculture, the Agrisciences Committee put its finger on some glaring gaps in the figures.

If all of the cows in the world came together to form a country, that nation state would be the second highest emitter of greenhouse gas emissions in the world.

McKinsey Sustainability’s statistic was certainly startling. However, Agrisciences Group Chair Jeraime Griffith mentioned other equally striking figures in his wrapup of the social media discussion generated at COP26.
In his talk as part of the Agrisciences Committee’s COP26 – What does it mean for the future of agriculture? webinar on 7 December, Griffith also noted that:

1. farming accounts for more than 70% of the freshwater used worldwide, according to the Organisation for Economic Co-operation and Development (OECD)
2. and 31% of human-caused greenhouse gas emissions come from agrifood systems, according to the Food and Agriculture Organisation.

On the face of it, these figures are sobering; yet, like many agriculture-related figures, they don’t tell the full story.

Insane in the methane

Kathryn Knight felt that agriculture received negative press at COP26 in relation to greenhouse gas emissions. ‘It doesn't seem to take into account carbon sequestration (capturing and storing atmospheric carbon dioxide),’ said the Research & Technology Manager of Crop Care at Croda. ‘Why isn’t that being brought into the equation when we’re talking about carbon and agriculture?’
Martin Collison expanded on this point. He emphasised the need to separate carbon emissions by system – such as extensively grazed livestock animals and those fed on grain – and to account for systems that sequester carbon in the soil. The co-founder of agricultural consultancy Collison & Associates also pointed out the problem with bundling all our greenhouse gases as one.

Greenhouse gas emissions are sometimes unhelpfully bundled together, instead of being separated by gas and agricultural system.

‘We count methane in the same way we emit carbon,’ he said. ‘When we emit carbon, it’s in the atmosphere for 1,000 years, but with methane it’s 12 years. The methane cycle is a lot, lot shorter.’

And the difficulties with the statistics don’t end there. For example, countries often announce impressive emission reductions without taking trade into account. This, of course, gives the figures a greener gloss.

‘To me, there's a need to be more up front with a lot of the data because agriculture and food are traded around the world,’ he added. ‘A lot of the emissions data ignore what we trade.

‘In the UK, we make big claims about how fast we’ve progressed with carbon emissions, but if you look at what we consume, the progress is much much slower. The things we produce less of, we import.’

>> SCI was at COP26 too! Read about the role of chemistry in creating a greener future.

Full of hot air?

Emissions trading also serves to blur the picture. For Jeraime Griffith it is an unsatisfactory solution. ‘In terms of carbon trading, we have cases where the higher emitters continue producing in the way they’ve always been producing,’ he said.

‘It doesn't bring in any restrictions on the amount of carbon they emit; it just shifts the problem somewhere else. I don't know how carbon trading benefits us getting to Net Zero. It just seems to be kicking the ball farther down the road.’

Is emissions trading part of the solution or part of the problem?

So, when you take into account 1. emissions trading, 2. the absence of food imports in data sets, 3. the bundling together of different greenhouse gases in emissions figures, and 4. the failure to take carbon sequestration into account, it’s clear that many of the statistics we receive are incomplete.

‘There’s lots of complexity behind the numbers and we tend to lump all of it together,’ Collison said. ‘There’s a need to go much much further.’

>> SCI’s Agrisciences Group is a unique multidisciplinary network covering the production, protection and utilisation of crops for food and non-food products. It has 250 members including academic and industry leaders, researchers, consultants, students, and retired members. If you’re interested in joining the group, go to: www.soci.org/interest-groups/agrisciences

Gardens in December should, provided the weather allows, be hives of activity and interest. Many trees and shrubs, especially Roseaceous types, offer food supplies especially for migrating birds.

Cotoneaster (see image below) provides copious fruit for migrating redwings and waxwings as well as resident blackbirds. This is a widely spread genus, coming from Asia, Europe and northern Africa.

Cultivated as a hedge, it forms thick, dense, semi-evergreen growth that soaks up air pollution. In late spring, its white flowers are nectar plants for brimstone and red admiral butterflies and larval food for moths. Children and pets, however, should be guided away from the attractive red berries.

Cotonester franchetti | Image credit: Professor Geoff Dixon.

Medlars (Mespilus germanica) offer the last fruit harvest of the season (see image below). These small trees produce hard, round, brownish fruit that require frosting to encourage softening (bletting).

Its soft fruit can be scooped out and eaten raw and the taste is not dissimilar to dates. Alternatively, medlar fruit can be baked or roasted and, when turned into jams and jellies, they are delicious, especially spread on warm scones.

Like most rosaceous fruit, medlars are nutritionally very rich in amino acids, tannins, carotene, vitamins C and B and several beneficial minerals. As rich sources of antioxidants medlars also help reduce the risks of atherosclerosis and diabetes.

Medlar fruit (Mespilus germanica) can be turned into jams and jellies | Image credit: Professor Geoff Dixon.

Garden work continues through December. It is a time for removing dead leaves and stems from herbaceous perennials, lightly forking through the top soil and adding granular fertilisers with high potassium and phosphate content.

Top fruit trees gain from winter pruning, which opens out their structure, allowing air circulation when fully laden with leaves, flowers and fruit. Fertiliser will feed and encourage fresh root formation as spring progresses.

The vegetable garden is best served by digging and incorporating farm yard manure or well-rotted compost, which adds fertility and encourages worm populations. The process of digging is also a highly beneficial exercise for the gardener (see illustration no 3).

Turning the soil isn’t only good for your garden - it boosts your wellbeing | Image credit: Professor Geoff Dixon.

Developing a rhythm with this task supports healthy blood circulation and, psychologically, provides huge mental satisfaction in seeing a weedy plot transformed into rows of well-turned bare earth.

When the weather turns wet, windy and wintery it provides opportunities for cleaning, oiling and sharpening tools, inspecting stored fruit and the roots of dahlias kept in frost-proof conditions.

Finally, there is always the very relaxing and pleasant task of reading through seed and plant catalogues and planning what may be grown in the coming seasons.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

How has climate change changed the way our gardens grow and what can be done to alleviate its effects? Professor Geoff Dixon tells us more.

Climate has changed on Earth ever since it solidified and organic life first emerged. Indeed, the first photosynthesising microbes changed the atmosphere from carbon dioxide rich to oxygen rich over millions of years. What we now face is very rapid changes brought about by a single organism, mankind, through industrialisation.

The effects of change are very evident in gardens. Over a generation, leaf bud breaking and flowering by early spring bulbs, herbaceous plants, shrubs and trees has advanced by at least four weeks (see main image of Cyclamen hederifolium).

Latter spring displays have advanced by at least two weeks. This is caused by milder, wetter winter weather, encouraging growth. The danger lies in the increasing frequency of short sharp spells of severe frost and snow. These kill off precocious flowers and leaves which trees especially cannot replace.

Desiccated, cracked soil.

Increasingly, the summer climate is becoming hotter and drier. Since the Millennium there has been a succession of hot droughts. These seriously limit scope for growing vegetables, fruit and ornamentals unless irrigation is regularly available. Drought also damages soil structure especially where there is a high clay content by causing cracking and the loss of plant cover (see image of desiccated, cracked soil above).

Cracking disrupts and destroys the root systems of trees and shrubs in particular. The effects of root damage may not become evident until these plants die in the following years. 

Climate change is apparently advantageous for microbes. Detailed surveys show that fungal life cycles are speeding up, increasing the opportunities for diseases to cause damage. Even normally quite resilient crops such as quince are being invaded during milder, damper autumns (See image of brown rot on quince fruit below). Throughout gardens, the range and aggressiveness of pests and disease is increasing.

Brown rot (Monilia laxa) on quince fruit.

However, each individual garden or allotment, no matter its size, can contribute to reducing the rate of climate change. Simple actions include the removal of hard landscaping, and planting trees and shrubs reduces carbon emissions.

Using electric-powered tools and machinery in place of petrol or diesel has similar advantages. Tumbling down parts of a garden into native flora, and perhaps encouraging rarer plants such as wild orchids or fritillarias, mitigates climate change. Such areas may also form habitats for hedgehogs or slow worms, increase populations of bees, butterflies and moths and encourage bird life. 

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

All images from Professor Geoff Dixon.

Lilies provide gloriously beautiful and well scented flowering border plants. Choose flowering size bulbs in the garden centre or from a catalogue. Grow these through the winter potted in a general garden compost placed in an unheated greenhouse or cold frame. By March or early-April, substantial green shoots will have formed from the bulbs and they can be transplanted into the garden.

Lilies need a sunny border and very fertile soil to encourage vigorous root growth capable of supporting the flowering spike and ancillary bulbs as they are initiated. This produces magnificent flowers and an increasing colony of bulbs that will spread and become established over future seasons.

Lilium longiflorum, often called the Easter lily | Image credit: Professor Geoff Dixon.

Regular watering and feeding with nutrients are needed, especially potassium, which encourages root and shoot growth. Stake the flower spike as it grows, giving support for the flowers because they are heavy when fully open and easily damaged by winds.

Rewards come in mid-summer with magnificent colourful flowers and wonderful perfumes on warm evenings. Apart from severe winters, lilies are hardy garden plants unless they are from groups specified as tender and requiring protection. In the autumn, simply cut down the flowering spike and remove any fallen foliage.

Buds developed on lily scales after culturing | Image credit: Professor Geoff Dixon.

The Lilium genus has about 100 species originating worldwide mainly from north temperate areas of Europe, Asia and America. The colour range includes white, yellow, orange, pink, red and purple. Plant breeders in The Netherlands, Japan and North America have produced a huge range of multi-coloured hybrids.

Taxonomically, Lilium is divided into divisions, of which the Turk’s Caps, Martagons and American hybrids are popular. The most destructive pest is the scarlet lily beetle (Lilioceris lilii) which devours foliage, flowers and bulbs. The first signs of trouble are shot holes in the foliage. Picking off beetles and larvae is an effective means of dealing with low-level infestations.

Comparison of lily bulbils growing from scale leaves, immature bulb and flowering size bulb | Image credit: Professor Geoff Dixon.

Asexual propagation is a simple and enjoyable occupation. Divide a good-sized bulb into its scales. Choose healthy scales from the outer rings and place these in a plastic box containing damp kitchen paper and place in an airing cupboard. After about 10-12 weeks, small bulbils will have formed on each scale.

Select the boldest mother scales and bulbils and plant in a tray of seedling compost and grow in the greenhouse. After two or three months the most vigorous young plants can be potted individually. Eventually these are planted in the garden and will develop into flowering size bulbs after two or three years.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

If you’re a vegan, do you really want to eat a ruby-red slab of plant protein that looks like lamb? If you are a health obsessive, would you opt for an ultra-processed, plant-based product if you knew it didn’t contain many vitamins and micro-nutrients? And why, oh why, are we so obsessed with recreating the taste and appearance of the humble hamburger?

These questions and more were posed by Dr David Baines in the recent ‘No meat and two veg – the chemistry challenges facing the flavouring of vegan foods’ webinar organised by SCI’s Food Group. The flavourist, who owns his own food consultancy and is visiting Professor at the University of Reading, painted a vivid picture of our changing culinary landscape – one in which 79% of Millennials regularly eat meat alternatives.

And this shift in diet isn’t just the preserve of the young. According to Dr Baines, 54% of Americans and 39% of Chinese people have included more plant-based foods and less meat in their diets. Furthermore, 75% of Baby Boomers – those born between 1946 and 1964 – are open to trying cultivated meat.

There are many reasons for this gradual shift. The woman biting into Greggs’ famous vegan sausage roll and the woman who carefully crafts her bean burger may have different reasons for choosing meat alternatives. For some, it’s an ethical choice. For others, it’s environmental or health-related. And then there are those of us who are simply curious.

Pea protein powder is used in plant-based meat alternatives.

Either way it’s an industry that, if you’ll excuse the pun, is set to mushroom. According to Boston Consulting Group and Blue Horizon research, the global meat-free sector will be worth US$290 billion by 2035. They also claim Europe will reach peak meat consumption by 2025, and Unilever is aiming to sell US$1 billion-worth of plant-based meat and dairy alternatives by 2025-27.

In his entertaining talk, Dr Baines outlined the extrusion processes that turn wheat and pea proteins into large ropes of fibrous material and how soy isolates are spun into textured proteins using looms like those used in the cotton industry. He explained how calcium is used to imitate the chewable texture of chicken and how Impossible Foods is using the root nodules of bean plants to produce the red colour we recognise so readily in meat.

>> For more interesting SCI webinars on battery developments, medicinal chemistry and more, check out our events page.

So, how close are we to products with the appearance, taste and texture of, let’s say, beef? ‘I think that will come from cultured meat to start with,’ he said. ‘Where the protein is produced, it will still need to be flavoured, but the fibres will have formed and the texture is already present in some of those products.

‘It’s a big ask and it’s been asked for a long time. It’s going to be a long time before you put a piece of steak on one plate and a plant-based [product] on another and they will be visually, texturally and taste(-wise] identical.’

And what appetite do people even have for these plant-based facsimiles? ‘There are people who want plant proteins not to look like meat, and there are people who want them to look like meat,’ he added. ‘The driver at the moment is to make them look like meat, and the driver is to make it taste like meat too.’

Baines wondered aloud about the bizarre fixation some have with recreating and eating foods that look and taste like beef burgers. In contrast, he pointed to the examples of tofu and soy-based products that have been developed in South East Asia – distinct foods that do not serve as meat substitutes.

Plant-based proteins are undoubtedly part of our culinary future, but these products have other barriers to surmount beyond taste and texture. There is no getting around the fact that plant-based proteins are ultra-processed in a time when many are side-stepping processed foods. Baines also explained that these protein- and fibre-rich foods tend to have lower calorific content, but lack vitamins and micronutrients. ‘Will they be supplemented?’ Baines asked. ‘How much will the manufacturers of these new products start to improve the nutritional delivery of these products?’

We have now entered the age of the gluten-free, vegan sausage roll.

But it’s easy to forget that the leaps made in recent years have been extraordinary. Who would have predicted back in 1997 – when Linda McCartney was at the vanguard of the niche, plant-based meat alternative – that a vegan sausage roll would capture the imaginations of a meat-hungry nation? Who would have foreseen fast-food manufacturers falling over each other to launch plant-based burgers and invest in lab-grown meat?

As Dr Baines said: “This is a movement that is not going away.”

>> Our soils provide 97% of our food. Read more about how they are undervalued and overused here.

Main image: Pea crop | Image credit: Geoff Dixon

Peas are a very rewarding garden crop. Husbandry is very straightforward, producing nutritious yields and encouraging soil health by building nitrogen reserves for future crops.

Rotations usually sequence cabbages and other nitrogen-demanding crops after peas. This is a sustainable way to use the organic nitrogen reserves left by pea roots resulting from their mutually beneficial association with benign bacteria. These microbes capture atmospheric nitrogen, producing ammonia, nitrites and nitrates in a sequence of natural steps.

Peas originated in the Mediterranean. They were cultivated continuously by ancient civilisations and through medieval times, and are now the seventh most popular vegetable.

Illustration 1: Pea seeds | Image credit: Geoff Dixon

In bygone centuries, peas provided a protein source for the general population as cooked meals of pea soup and pease pudding helped keep famine at bay before the introduction of potatoes. In the 18th century, French gardeners working for the aristocracy produced fresh peas using raised and protected beds of fermenting animal manure. The composting processes produced heat and released carbon dioxide, stimulating rapid growth.

Generally, however, eating fresh peas only gained popularity in the 20th century as canned and then quick-frozen foods were invented, and large-scale technological development enabled mechanised and automated commercial precision cropping. In recent times, retail market demand has returned for unshelled podded peas – a manually picked crop known colloquially as ‘pulling peas’.

How to grow peas

Seeds can be sown directly (illustration 1) or transplants (illustration 2) can be raised under protection, giving an early boost for growth and maturity. Peas are cool season crops. They grow best at 13-18°C and mature about 60 days after sowing.

Illustration 2: Pea seedlings | Image credit: Geoff Dixon

Some cultivars such as Meteor can be grown over winter, preferably protected with cloches for very early cropping. The spring sown The Sutton cultivar group (CV) gives rapid but modest returns, and main crop CVs, such as Hurst Green Shaft, deliver the heaviest returns (illustration 2). This cultivar forms several long, well-filled pods at the fruiting nodes.

Sugar peas or mange tout – where the entire immature pod is eaten – is a popular fresh crop, while quick-growing pea shoots that mature in 20 days from sowing are excellent additions for salads or as garnishes for warm cuisine.

Human health benefits significantly by including peas in the diet. As well as being an excellent protein source, they produce a range of vitamins and nutrient elements. Their coumestrol content aids the control of blood sugar levels, helping combat diabetes, heart diseases and arthritis.

So, it’s certainly worth finding a spot for this versatile vegetable in your garden.

Written by Professor Geoff Dixon, author of Garden practices and their science.

Think of Earth as an apple and the soil as the peel. Now, imagine that more than 70% of this apple’s surface is covered in water. That veneer of peel suddenly seems very small indeed.

Dig beneath the surface and you realise that the world’s soil resources aren’t as plentiful as you first thought. When you take into account all of the uninhabitable, non-arable land on our planet, including the snow-bound poles and deserts, you’re left with just 3% of total landmass to grow all the fruit and vegetables we eat.

After reminding her listeners of some stark facts at the Soil resources in the UK: overlooked and undervalued? webinar, Jane Rickson, Professor of Soil Erosion and Conservation at Cranfield University, reminded us that soil is a precious, finite resource. “We’re dealing with a very thin resource that has to deliver all of these goods and services.”

You just need to think of your breakfast, lunch, and dinner to realise just how important soil is. Of all the food we eat, 97% comes from terrestrial sources. However, in recent decades, the many benefits brought by soil have been taken lightly. Apart from providing food, animal fodder, and a surface for football, it plays a vital role in climate change mitigation.

‘Soil is excellent for climate change mitigation,’ said Professor Rickson, recipient of the prestigious Dr Sydney Andrew Medal for 2021. ‘We know that healthy soils can support vegetation and crops and plants in taking out atmospheric CO2.’

A cross section of soil layers. Unless you live on fish and seaweed, it’s likely that almost all of your food sources will come from terrestrial sources.

However, she and her colleagues at Cranfield University have unearthed some unsettling facts about the state of our soils. She mentioned that 12 million hectares of agricultural land worldwide is lost each year due to soil degradation. In the UK, soil erosion rates can be as high as 15 tonnes per hectare per year, with soil formation rates only compiling at a rate of 1 tonne per hectare per year; and, based on current rates of erosion, some soils could disappear completely by 2050.

So, what is being done to arrest this problem? The obvious mammoth in the room is climate change, with extreme weather events such as flash floods precipitating a huge amount of soil erosion. Obviously, climate change mitigation measures on a national scale would help, but adjustments to farming practices could also improve soil resilience on a more local level.

A lot of work is also being done to reduce the intensity of farming to improve soil health. The aim, according to Rickson, is to maintain a fertile seedbed while retaining maximum resistance to soil degradation. There are lots of different ways to do this.

One approach being taken is cover cropping, whereby a crop is grown for the protection and enrichment of the soil rather than for immediate sale. This enriches the soil and helps prevent soil erosion. Another approach is strip-tillage – a minimum tillage system that disturbs only the portion of the soil that contains the seed row, with the soil between rows left untilled. She also mentioned the benefits of soil improvement, with poultry manure and mushroom compost used to improve soil health by Benedict Unagwu among others.

Cover crops such as vetch and oats improve the structure and fertility of the soil.

It is difficult not to have sympathy for farmers at the moment. Climate change falls heavily upon their lands, and they must battle flooding and drought to keep their farms financially viable. Professor Rickson often speaks to the farming community about soil health, with the focus placed on realistic solutions. As one farmer told her: ‘It's hard to be green when you’re in the red.’

Perhaps soil doesn’t capture the imagination the same way as an oak forest or a field ablaze with wildflowers, but its mismanagement is costing us a fortune. She estimated that the combined annual economic cost of soil degradation in England, Scotland, and Wales is £1.5 billion.

According to Professor Rickson, the US is probably the home of soil conservation following the harsh ecological lessons learnt from the Dust Bowl disaster of the 1930s. However, she believes the UK has plenty of knowhow in the area.

‘The UK has an opportunity to be world-leading in this,’ she said. ‘I think we are as good as anyone. Our scientific community understands soil and is really pushing the boundaries in terms of soil science.’

Which technologies will propel industry forward and give companies that competitive advantage? According to digital consultancy McKinsey Digital’s Tech Trends Index, several technologies will have a profound and disruptive impact on industries including the chemical sector. So, which ones will have the biggest effect on the way you work in the coming decade?

1: Automation

By 2025, more than 50 billion devices around the world will be connected to the Industrial Internet of Things (IIOT) and about 600,000 industrial robots a year will be in place from 2022. The combination of these, along with industrial processes such as 3D and 4D printing, will speed up processing and improve operational efficiency.

According to McKinsey, 50% of today’s work practices could be automated by 2022 as ever more intelligent robots (in physical and software form) increase production and reduce lead times. So, how does this change look in the real world?

According to the McKinsey Tech Trends Index, 10% of today’s manufacturing processes will be replaced by additive manufacturing by 2030.

According to the Tech Trends Index, one large manufacturer has used collaborative robots mounted on automatic guided vehicles to load pallets without human involvement, while an automotive manufacturer has used IIOT to connect 122 factories and 500 warehouses around the world to optimise manufacturing and logistics, consolidate real-time data, and boost machine learning throughput.

2: Next generation computing

An almost incredible 368,000 patents were granted in next generation computing in 2020. Advanced computing will speed up the processing of reams of data to optimise research and cut development times for those in the chemicals and pharmaceuticals industries, accelerate the use of autonomous vehicles, and reduce the barriers to industry for many eager entrants.

‘Next-generation computing enables further democratisation of AI-driven services, radically fast development cycles, and lower barriers of entry across industries,’ the index notes. ‘It promises to disrupt parts of the value chain and reshape the skills needed (such as automated trading replacing traders and chemical simulations, reducing the need for experiments).’

According to McKinsey, AI will also be applied to molecule-level simulation to reduce the empirical expertise and testing needed. This could disrupt the materials, chemicals, and pharmaceuticals industries and lead to highly personalised products, especially in medicine.

3: The Bio-revolution

It doesn’t take much investigation before you realise that the bio-revolution has already begun. Targeted drug delivery and smart watches that analyse your sweat are just two ways we’re seeing significant change.

The Tech Trends Index claims the confluence of biological science and the rapid development of AI and automation are giving rise to a revolution that will lead to significant change in agriculture, health, energy and other industries.

In the health industry, it seems we are entering the age of hyper-personalisation. The Index notes that: ‘New markets may emerge, such as genetics-based recommendations for nutrition, even as rapid innovation in DNA sequencing leads ever further into hyper personalised medicine.’ One example of this at work in the agri-food industry is Trace Genomics’ profiling of soil microbiomes to interpret health and disease-risk indicators in farming.

4: Advanced materials

It’s no secret that we will need to develop lighter materials for transport, and others that have a lighter footprint on our planet. According to McKinsey, next generation materials will enhance the performance of products in pharma, energy, transportation, health, and manufacturing.

For example, molybdenum disulfide nanoparticles are being used in flexible electronics, and graphene is driving the development of 2D semiconductors. Computational materials science is another area of extraordinary potential. McKinsey explains: ‘More new materials are on the way as computational-materials science combines computing power and associated machine-learning methods and applies them to materials-related problems and opportunities.’

5G networks will help take autonomous vehicles from tentative - to widespread use.

So, which sorts of advanced materials are we talking about? These include nanomaterials that enable more efficient energy storage, lighter materials for the aerospace industry, and biodegradable nanoparticles as drug carriers within the human body.

These are just four of the 10 areas explored in the fascinating McKinsey Digital’s Tech Trends report. To read more about the rest, visit: https://www.mckinsey.com/business-functions/mckinsey-digital/our-insights/the-top-trends-in-tech

The iris family (Iridaceae) provides gardeners with a glorious array of colourful and frequently well scented flowers. Originating from both tropical and temperate regions, some such as freesias are best cultivated under protection. Others such as gladioli and crocus are reliable garden plants.

Iris, or fleur-de-lis, is one of the larger genera, offering colour and interest from the very earliest springtime through to May and June. The earliest and always most welcome is Iris unguicularis (previously Iris stylosa). Flowers (see illustration 1) emerge in the darkest days of December, encouraged by the warming effects of climate change.

Illustration 1: Iris unguicularis (syn Iris stylosa) / Image credit: Geoff Dixon

Originating from North Africa, it thrives in south facing dry borders, preferably under a wall where winter sunshine encourages proliferous flowering. Every few years, lift and divide the clump of small rhizomes after flowering has finished. Remove older growth and replant younger roots with a modest handful of compost and water well. Established clumps can be cut back, removing dead leaves during late spring.

By contrast Iris pseudacorus, the water flag, thrives in wet, boggy places or even when immersed in water. Found across Europe, it is a British native plant producing vivid yellow flowers that are rich sources of nectar. In parts of Scotland it forms large expanses of natural growth that are favoured by nesting corncrakes. It can be cultivated as part of water purification programmes since nitrogen and phosphorus are extracted by the vigorous root systems.

Illustration 2: Iris germanica / Image credit: Geoff Dixon

The prima donna is Iris germanica, the flag or bearded iris. These are stately plants, producing flower spikes up to one metre high and furnished with multicoloured flowers (illustration 2). Upright standard petals can contrast completely with the falls which bear a beard of yellow pollen bearing stamens. Fertiliser should be applied as the flower spikes appear. It should be applied again after flowering, stimulating root growth in anticipation of a colourful display in the next season.

Illustration 3: Rhizome ready for division / Image credit: Geoff Dixon

The rhizome is a large swollen ground-creeping stem from which side shoots develop with a terminal area of older tissue (illustration 3). Every four or five years, the rhizomes should be lifted and divided by removing the terminal tissue and splitting off side shoots with a sharp knife. These and the main rhizome should be replanted carefully, ensuring that they rest on the soil surface with their fibrous roots buried beneath them. Multiplication eventually provides a border filled with very colourful displays that can persist for a month since flowers frequently emerge along most of the spike.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

Watching plants grow in a hydroponic contraption is an education. The plants sit in foam under UV light while their roots feed on water fortified by plant feed. There is no soil. No thirst. No room for death by lazy gardener. The results, as any hydroponic enthusiast will tell you, are startling.

So, what if we were to adopt this targeted, optimised approach to our own nutrition? What would happen if he were to ditch that delicious Sunday roast in favour of a shake that contains all the vitamins and minerals your body needs? Admittedly, it sounds terrible, but people do something similar already. Many gym obsessives take protein shakes religiously to feed their bodies’ impressive musculature, while others skip meals entirely in favour of such drinks and supplements.

An organic hydroponic vegetable cultivation farm

A recent study conducted by the Cherab Foundation, which featured in the Alternative Therapies journal, concludes that nutritional supplements may also help boost our brain function. After giving 77 people a vitamin and meal replacement product called IQed Smart Nutrition, the researchers from the non-profit organisation found that the supplement boosted brain function in a range of areas and could help people with autism, apraxia, and ADHD.

Almost 84% of participants reported deficits in speech and communication prior to taking the nutritional supplements. After taking the product, more than 85% said their expressive speech had improved while 67% of respondents reported improvements in other areas including focus, language understanding, oral motor skills, and physical and behavioural health.

Overall, 64% of participants reported positive changes within two weeks. According to the Cherab Foundation, the research aims “to guide future research into the dietary interventions and potential management of neurological conditions using natural food products, vitamin and mineral supplements”.

So, what ingredients are in the supplement-infused chocolate shake that will replace the wood-fired pizza you’re due to have next Friday evening? According to IQed, its powdered chocolate offering contains everything from brown rice, apple fibres, turmeric, and green tea, to copper gluconate, amalaki, cayenne pepper, and chia seeds.

Turmeric, cayenne pepper, and chia seeds have hopped onto the superfood bandwagon in recent years.

Some will dismiss these supplements as hocus-pocus, but the potential benefits of optimised nutrition are exciting nonetheless. If some wince-inducing elixir makes us healthier, stronger and live longer, perhaps it’s worth investigating further?

The Cherub Foundation works to improve the communication skills, education, and advocacy of children on the neurological spectrum. To read more about its study, visit: https://pubmed.ncbi.nlm.nih.gov/32088673/

Farmers today are under pressure to produce more food with fewer resources and without damaging the environment around them. Faced with factors such as land pressures, soil fertility, pest management and agricultural policy, farming today is all about efficiency, time and energy saving technology, and the drive to make solutions as sustainable as possible.

This obviously poses the question: what can the agrochemical industry do to increase output on one hand and protect the environment and improve applicator safety on the other?

Formulation technology is becoming increasingly important in answering this question. By designing innovative formulations, agrochemical products can become more effective as well as safer. Without the right formulation, even the best active substance is worth nothing.

Most pesticidal active ingredients are not water soluble or water dispersible, yet the most common mode of delivery is via spray applications of aqueous dilutions. It is necessary to create a formulation of the active ingredient in a way that makes it easily dispersible in water and able to maintain stability over the application time period. Changing what goes into this formulation alongside the active ingredient is crucial in how effectively that material is delivered to where it needs to be.

Demonstration of an EC formulation.

Two of the most common types of agricultural formulations that tackle this issue are emulsifiable concentrates (ECs) and suspension concentrates (SCs). EC formulations are suited to active ingredients that are oil soluble and have low melting points. As they are purely a solubilised active ingredient in an oil or solvent with the presence of emulsifiers, they are simple to manufacture and relatively easy to stabilise. The presence of an oil also enhances the biological activity of the application, making them more efficacious in the field.

SC formulation, with an indication of what occurs upon dilution into the spray tank prior to application.

SC formulations, on the other hand, are suitable for insoluble active ingredients and those with higher melting points. Crucially, as water is the continuous phase, they are also typically safer and more convenient in use for the operator; there is an absence of dust, flammable liquids, and volatile organic compounds.

Built into each of these formulations alongside the active ingredient are formulation additives. Formulation additives, referred to as inert ingredients, are critical to provide the long-term stability to agrochemical products and their ability to mix effectively in the spray tank, making them suitable for [field spray] applications.

While the formulation type targeted is often dictated by the chemical characteristics of the active ingredient, the formulator has the ability to change every element of the spray quality characteristics and agrochemical delivery through selection of formulation additives. Changing both the formulation type and the additives within will habitually have a dramatic effect on the field efficacy of that application and subsequent yield and quality of the crop. Selecting the correct formulation additives is essential in creating a successful formulation, arguably making them as significant as the active ingredient itself.

How formulators learn to map the complex effects within formulations for improved crop protection is just one facet of today’s agriculture challenge.

Interested in learning more about how the formulation of agrochemicals plays its part in feeding the world? Visit: www.crodacropcare.com

Perennial bush soft fruits are among the crown jewels of gardening. Gooseberries, red currants and blackcurrants when well established will annually reward with crops of very tasty ripe fruit which provide exceptional health benefits. These bushes will mature into quite sizeable plants so only relatively few, maybe one to five of each will be sufficient for most home gardeners or allotment owners.

Header image: Gooseberries | Image credit: Geoff Dixon

The art of successful establishment lies in initial care and planting. Buy good quality dormant plants from reputable nurseries or garden centres. Plunge the roots deeply in a bucket of water and plant as quickly as possible. These crops need rich fertile soil which is weed free and has recently been dug over with the incorporation of farmyard manure or well-rotted compost. Each bush requires ample growing space with at least a one metre distance within and between rows.

Take out a deep planting hole and soak with water. Place the new bush into the hole, spreading out the root system in all directions. Add mycorrhizal powder around and over the roots, which encourages growth promoting fungi. These colonise the roots, aiding nutrient uptake and protecting from soil borne pathogens. Carefully fold the soil back around the roots, shaking the plant. That settles soil in and around the roots and up to the collar which shows where the plant had grown in the nursery. Tread around the collar to firm the plant and add more water. Normally, planting is completed in late winter to early spring before growth commences.

Redcurrants | Image credit: Geoff Dixon

As buds open in spring, keep the plants well-watered. It is crucially important that the young bushes do not suffer drought stress, especially during the first summer. Supplement watering with occasional applications of liquid feed which contains large concentrations of potassium and phosphate plus micro nutrients. Remove all weeds and flowers in this first year. That concentrates all the products of photosynthesis into root, shoot and leaf formation for future seasons. Clean up around the plants in autumn, removing dead leaves that might harbour disease-causing pathogens.

These plants will flower and fruit from the first establishment year. Each bush will produce fruit which is a succulent and rewarding source of health-promoting vitamins and nutrients.

Blackcurrants | Image credit: Geoff Dixon

Blackcurrants are a fine source of vitamin C and have twice the antioxidant content of blueberries. Redcurrants are sources of flavonoids and vitamin B, while gooseberries are rich in dietary fibre, copper, manganese potassium and vitamins C, B5 and B6.

Blackbirds also like these fruits so netting or cages are needed! Continuing careful husbandry will yield a succession of expanding and rewarding crops.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

To some, the almond is a villain. This admittedly tasty nut takes an extraordinary amount of water to grow (1.1 gallons per nut) and some in California say almond cultivation has contributed to drought.

And so it is no surprise to see the almond lined up in the rogue’s gallery of the thirstiest foods. In a study in the journal Nature Food, University of Michigan (U-M) and Tulane University researchers assessed how the food we eat affects water scarcity.

Meat consumption was found to be the biggest culprit in the US, with the hooves and feet of livestock accounting for 31% of the water scarcity footprint. Within the meat category, beef is the thirstiest, with almost six times more water consumption than chicken.

Almond crops in California have come under heavy criticism due to their heavy water consumption

However, the picture is a little more nuanced. Lead author Martin Heller, of U-M's School for Environment and Sustainability, explains: “Beef is the largest dietary contributor to the water scarcity footprint, as it is for the carbon footprint. But the dominance of animal-based food is diminished somewhat in the water scarcity footprint, in part because the production of feed grains for animals is distributed throughout less water-scarce regions, whereas the production of vegetables, fruits and nuts is concentrated in water-scarce regions of the United States, namely the West Coast states and the arid Southwest.”

Certain types of diets drain the water supply. People who eat large quantities of beef, nuts such as the infamous almond, walnut, and cashew, and a high proportion of water-intense fruits and vegetables including lemon, avocado, asparagus, broccoli, and cauliflower take a heavy toll on the water footprint.

The Brussels sprout is not just for Christmas… it is a less water intense option for your dinner table.

“The water-use impacts of food production should be a key consideration of sustainable diets,” adds study co-author Diego Rose of Tulane University. “There is a lot of variation in the way people eat, so having a picture with this sort of granularity – at the individual level – enables a more nuanced understanding of potential policies and educational campaigns to promote sustainable diets.”

So, what do you do the next time you feel a pang of water guilt? According to the researchers, you could swear off asparagus and that crushed avocado on your toast and replace them with less water intense foods such as fresh peas, Brussels sprouts, cabbage, and kale (but maybe not on your toast). Those beef steaks and hamburgers could make way for other protein sources, such as chicken, pork, and soybeans, and you could graze on peanuts and seeds instead of those honey roasted almonds you love so dearly. Just think of all those gallons of water you’ll save.

For more on this study, visit: https://www.nature.com/articles/s43016-021-00256-2

Variously known as zucchini, courgette, baby marrows and summer squash, this frost tender crop is a valuable addition for gardens and allotments. Originating in warm temperate America, the true zucchini was developed by Milanese gardeners in the 19th century and popularised in the UK by travellers in Italy. It quickly matures in 45 to 50 days from planting out in open ground by early May in the south and a couple of weeks later farther north.

Alternatively, use cloches as frost protection for early crops. Earliness is also achieved by sowing seed in pots of openly draining compost by mid-April in a greenhouse or cold frame. Courgettes have large, energy-filled seeds. Consequently, germination and subsequent growth are rapid.

Sow seed singly in 10cm diameter pots and plant out when the first 2-3 leaves are expanding (illustration number 1). Alternatively, garden centres supply transplants. These should be inspected carefully, avoiding those with yellowing leaves or wilting foliage. Each plant should have white healthy-looking roots without browning.

Illustration 1: Courgette seedlings germinated in a greenhouse.

Courgettes grow vigorously and each plant should be allocated at least 1 metre spacing within and between rows. They require copious watering and feeding with a balanced fertiliser containing equal quantities of nitrogen, phosphorus and potassium.

Botanically, they are dioecious plants, having separate male and female flowers, (illustration number 2). They are beloved by bees, hence supporting biodiversity in the garden. Slugs are their main pest, causing browsing wounds on courgette fruits; mature late-season foliage is usually infected by powdery mildew fungi that cause little harm.

Illustration 2: Bee-friendly (and tasty) courgette flower.

Quick maturing succulent courgettes are hybrid cultivars, producing harvestable 15-25 cm long fruit (berries) before the seeds begin forming (illustration number 3). Harvest regularly at weekly intervals before the skins (epicarps) begin strengthening and toughening. Skin colour varies with different cultivars from deep green to golden yellow. The choice rests on gardeners’ preferences.

Courgettes are classed and cooked as vegetables and their dietary value is retained by steaming thinly sliced fruits. Courgettes are a low-energy food but contain useful amounts of folate, potassium and vitamin A (retinol). The latter boosts immune systems, helping defend against illness and infection and increasing respiratory efficiency. Eyesight is also protected by increasing vision in low light.

Illustration 3: Courgette fruit ready for the table.

Courgettes are, therefore, valuable dietary additions year-round. Courgette flowers are bonuses, used as garnishes or dipped in batter as fritters or tempura. Overall, the courgette is a most useful plant that provides successional cropping using ground vacated by over-wintered vegetables such as cabbage, Brussels sprouts or leeks.

Written by Professor Geoff Dixon, author of Garden practices and their science, published by Routledge 2019.

Broad beans are an undemanding and valuable crop for all gardens. Probably originating in the Eastern Mediterranean and grown domestically since about 6,000BC, this plant was brought to Great Britain by the Romans.

Header image: a rich harvest of succulent broad beans for the table

Capable of tolerating most soil types and temperatures they provide successional fresh pickings from June to September. Early crops are grown from over-wintered sowings of cv Aquadulce. They are traditionally sown on All Souls Day on 2 November but milder autumns now cause too rapid germination and extension growth. Sowing is best now delayed until well into December. Juicy young broad bean seedlings offer pigeons a tasty winter snack, consequently protection with cloches or netting is vital insurance.

From late February onwards dwarf cultivars such as The Sutton or the more vigorous longer podded Meteor Vroma are used. Early cropping is promoted by growing the first batches of seedlings under protection in a glasshouse. Germinate the seed in propagating compost and grow the resultant seedlings until they have formed three to four prominent leaflets. Plant out into fertile, well-cultivated soil and protect with string or netting frameworks supported with bamboo canes to discourage bird damage.

Young broad bean plants supported by string and bamboo canes

More supporting layers will be required as the plants grow and mature. Later sowings are made directly into the vegetable garden. As the plants begin flowering remove the apical buds and about two to three leaves. This deters invasions by the black bean aphid (Aphis fabae). Winged aphids detect the lighter green of upper foliage of broad beans and navigate towards them!

Allow the pods ample time for swelling and the development of bean seeds of up to 2cm diameter before picking. Beware, however, of over-mature beans since these are flavourless and lack succulence. Broad beans have multiple benefits in the garden and for our diets. They are legumes and hence the roots enter mutually beneficial relationships with nitrogen fixing bacteria. These bacteria are naturally present in most soils. They capture atmospheric nitrogen, converting it into nitrates which the plant utilises for growth. In return, the bacteria gain sources of carbohydrates from photosynthesis.

Broad bean root carrying nodules formed around colonies of nitrogen fixing bacteria

Broad beans are pollinated by bees and other beneficial insects. They are good sources of pollen and nectar, encouraging biodiversity in the garden. Nutritionally, beans are high in protein, fibre, folate, Vitamin B and minerals such as manganese, phosphorus, magnesium and iron, therefore cultivating healthy living. Finally, they form extensive roots, improving soil structure, drainage and reserves of organic nitrogen. Truly gardeners’ friends!

Professor Geoff Dixon, author of Garden practices and their science (ISBN 978-1-138-20906-0) published by Routledge 2019.

Thinking of popping to your nearest specialist store for some sesame oil, turmeric, or soy? Some things haven't changed in 3,700 years, it turns out...

At least, that's what a growing new field of research, palaeoproteomics, suggests. Human mouths are full of bacteria, which continually petrify and form dental calculus — which can entrap and preserve tiny food particles. These remnants can be accessed and analysed thousands of years later, providing remarkable insight into the dietary habits of our ancestors.

Philip Stockhammer, an archaeologist at the Ludwig Maximilian University of Munich (LMU), has worked with Christina Warinner, a molecular archaeologist at Harvard University and the Max Planck Institute for the Science of Human History, and a team of researchers to apply this new method to the eastern Mediterranean, including the Bronze Age site of Megiddo and the Early Iron Age site of Tel Erani.

“Our high-resolution study of ancient proteins and plant residues from human dental calculus is the first of its kind to study the cuisines of the ancient Near East,” said Warinner, explaining its significance. “Our research demonstrates the great potential of these methods to detect foods that otherwise leave few archaeological traces. Dental calculus is such a valuable source of information about the lives of ancient peoples.”

High-resolution analyses of ancient dental calculus have given us a whole new perspective on the diets of Bronze Age people.

The research team took samples from a range of individuals and analysed which food proteins and plant residues were preserved in their teeth. “This enables us to find traces of what a person ate,” said Stockhammer. “Anyone who does not practice good dental hygiene will still be telling us archaeologists what they have been eating thousands of years from now!”

Of course, it's not quite as simple as looking at the teeth of those who didn't thoroughly clean them nearly four millennia ago and hoping the proteins survived. “Interestingly, we find that allergy-associated proteins appear to be the most stable in human calculus”, remarked Ashley Scott, LMU biochemist and lead author. That might be because of the known thermostability of many allergens. For instance, the researchers were able to detect wheat via wheat gluten proteins, which they independently confirmed with a different method using a type of plant microfossil known as phytoliths.

This substance has previously been used to identify millet and date palm in the same area during the Bronze and Iron Ages but phytoliths are not plentiful or even present in many foods, which is why this research is so exciting — palaeoproteomics means foods that have left few other traces, such as sesame, can now be identified.

Research suggests that the humble banana was eaten throughout the Mediterranean far earlier than first thought.

The method has allowed the team to identify that people at these sites ate, among other things, sesame, turmeric, soy, and bananas far earlier than anyone had realised. “Exotic spices, fruits and oils from Asia had thus reached the Mediterranean several centuries, in some cases even millennia, earlier than had been previously thought,” explained Stockhammer.

The finds mean that we have direct evidence for a flourishing long-distance trade in fruits, spices, and oils, from East and South Asia to the Levant via Mesopotamia or Egypt as early as the second millennium BCE.

More than that, the analyses "provide crucial information on the spread of the banana around the world. No archaeological or written evidence had previously suggested such an early spread into the Mediterranean region,” according to Stockhammer (although the sudden appearance of bananas in West Africa a few centuries later has previously led archaeologists to believe that such a trade might have existed, this is the first evidence).

The team acknowledged that other explanations are possible, including that the individuals concerned had travelled to East or South Asia at some point but there is evidence for other trade in food and spices in the Eastern Mediterranean — for instance, we know Pharaoh Ramses II was buried with peppercorns from India in 1213 BCE.

But it certainly seems like some foods might have been popular in the Mediterranean for much longer than we realised, which might be an interesting thought to accompany you next time you add some spices or bananas to your shopping basket.

More people are looking at their nutritional intake, not only to improve wellbeing but also reduce their environmental impact. With this, comes a move to include foods that are not traditionally cultivated or consumed in Europe.

Assessing whether this growing volume of so called ‘novel foods’ are safe for human consumption is the task of the European Food Safety Authority. The EFSA points out, ‘The notion of novel food is not new. Throughout history new types of food and food ingredients have found their way to Europe from all corners of the globe. Bananas, tomatoes, tropical fruit, maize, rice, a wide range of spices – all originally came to Europe as novel foods. Among the most recent arrivals are chia seeds, algae-based foods, baobab fruit and physalis.’

Under EU regulations any food not consumed ‘significantly’ prior to May 1997 is considered to be a ‘novel food’. The category covers new foods, food from new sources, new substances used in food as well as new ways and technologies for producing food. Examples include oils rich in omega-3 fatty acids from krill as a new source of food, phytosterols as a new substance, or nanotechnology as a new way of producing food.

Providing a final assessment on safety and efficacy of a novel food is a time consuming process. At the start of 2021 the EFSA gave its first completed assessment of a proposed insect-derived food product. The panel on Nutrition, Novel Foods and Food Allergens concluded that the novel food dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption.

Dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption, according to the EFSA.

Commenting in a press statement, as the opinion on insect novel food was released, Ermolaos Ververis, a chemist and food scientist at EFSA who coordinated the assessment said that evaluating the safety of insects for human consumption has its challenges. ‘Insects are complex organisms which makes characterising the composition of insect-derived products a challenge. Understanding their microbiology is paramount, considering also that the entire insect is consumed,’

Ververis added, ‘Formulations from insects may be high in protein, although the true protein levels can be overestimated when the substance chitin, a major component of insects’ exoskeleton, is present. Critically, many food allergies are linked to proteins so we assess whether the consumption of insects could trigger any allergic reactions. These can be caused by an individual’s sensitivity to insect proteins, cross-reactivity with other allergens or residual allergens from insect feed, e.g. gluten.’

EFSA research could lead to increased choice for consumers | Editorial credit: Raf Quintero / Shutterstock.com

The EFSA has an extensive list of novel foods to assess. These include dried crickets (Gryllodes sigillatus), olive leaf extract, and vitamin D2 mushroom powder. With the increasing desire to find alternatives to the many foods that we consume on a regular basis, particularly meat, it is likely that the EFSA will be busy for some time to come.

Gardens and parks provide visual evidence of climate change. Regular observation shows us that our flowering bulbous plants are emerging, growing and flowering. Great Britain is particularly rich in long term recordings of dates of budbreak, growth and flowering of trees, shrubs and perennial herbaceous plants. Until recently, this was dismissed as ‘stamp collecting by Victorian ladies and clerics’.

The science of phenology now provides vital evidence that quantifies the scale and rapidity of climate change. Serious scientific evidence of the impact of climate change comes, for example, from an analysis of 29,500 phenological datasets. This research shows that plants and animals are responding consistently to temperature change with earlier blooming, leaf unfurling, flowering and migration. This scale of change has not been seen on Earth for the past three quarters of a million years. And this time it is happening with increased rapidity and is caused by the activities of a single species – US – humans!

Iris unguicularis (stylosa). 

Changing seasonal cycles seriously affects our gardens. Fruit trees bloom earlier than previously and are potentially out of synchrony with pollinators. That results in irregular, poor fruit set and low yields. Climate change is causing increased variability in weather events. This is particularly damaging when short, very sharp periods of freezing weather coincide with precious bud bursts and shoot growth. Many early flowering trees and shrubs are incapable of replacing damaged buds, as a result a whole season’s worth of growth is lost. Damaged buds and shoots are more easily invaded by fungi which cause diseases such as dieback and rotting. Eventually valuable feature plants fail, damaging the garden’s benefits for enjoyment and relaxation. 

Plant diseases caused by fungi and bacteria benefit from our increasingly milder, damper winters. Previously, cooling temperatures in the autumn and winter frosts prevented these microbes from over-wintering. Now they are surviving and thriving in the warmer conditions. This is especially the case with soil borne microbes such as those which cause clubroot of brassicas and white rot, which affects a wide range of garden crops.

Hazel (Coryllus spp.) typical wind-pollinated yellow male catkins, which produce pollen.

Can gardeners help mitigate climate change? Of course! Grow flowering plants which are bee friendly; minimise using chemical controls; ban bonfires – which are excellent sources of CO2; establish wildlife-friendly areas filled with native plants and pieces of rotting wood, and it is amazing how quickly beneficial insects, slow worms and voles will populate your garden.

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Professor Geoff Dixon is the author of Garden Practices and their Science, published by Routledge 2019.