February 7, 2017

Countering the Courgette Crisis

It seems we are facing a Courgette Crisis. Although it’s really just a bit of a run on green vegetables, it does remind us that actually, courgettes – and now iceberg lettuce – shouldn’t be ‘February vegetables’. This raises some important issues about what we as consumers have learned to expect when it comes to food.

Not long ago, we used to pickle, preserve, freeze and store our fruit and vegetables to see us through the winter. These days you can pick up a rainbow of internationally-grown, out-of-season fresh produce anytime. If you want a strawberry on Christmas day, you can have one.

“Now we, the public, expect soft fruit, salad crops and many vegetable varieties to be readily available on supermarket shelves in the depths of the British winter, it has come as a bit of a shock not to be able to buy a courgette or an iceberg lettuce when we want one,” explains Dr Rosemary Collier, director of the Warwick Crop Centre and academic lead on food – one of the University of Warwick’s Global Research Priorities.

“The reason these particular vegetables and others, like baby spinach, tomatoes and certain types of broccoli, have been in short supply is because the growing regions of Spain and Italy are experiencing unusually cold weather at the moment,” says Dr Collier

“Britain actually imports about 50-60 per cent of our vegetables and about 20 per cent of our fruit, but this proportion is higher in the winter when our own production is less. We grow brassicas – like purple sprouting broccoli, cauliflower, cabbages and sprouts – as well as carrots and parsnips, for harvest during the winter months and are virtually self-sufficient in these. But it is hard for the UK to produce salad on a large commercial scale in winter as the species we eat – at present – are not very cold tolerant. So now, as political and trade systems are in flux and the impacts of climate change are becoming ever more real, perhaps we should look at our food system and consider what we want from it,” she adds.

Maybe we should be eating more ‘winter veg’ in the winter months, particularly if we can make it even more sustainable. Applied research at the Warwick Crop Centre, a specialist hub of Warwick’s School of Life Sciences’ based at the University’s Wellesbourne Campus, is looking at ways of improving existing UK vegetable and fruit crops as well as looking for completely new ones.

Grown improvement

One of the areas where the Crop Centre is involved in is the Brassica, Rapeseed and Vegetable Optimisation (BRAVO) project. The new five-year venture, in which Warwick is a key player, aims to make some of the UK’s traditional and most valuable crops more resilient. Oilseed rape and brassica vegetable crops have a combined UK market value in excess of £1 billion, but suffer yearly losses of up to £230 million, primarily due to increasingly unfavourable and unpredictable weather patterns.

Funded by the Biotechnology and Biological Sciences Research Council (BBSRC), scientists aim to combat losses of oilseed rape and brassica vegetable crops by unravelling the processes that control key aspects of plant development. The knowledge gained from the programme will be applied to help develop new types of brassica crops that will be more robust and reduce waste.

The Warwick Crop Centre is also a lead partner in the Vegetable Genetic Improvement Network (VeGIN) which is funded by Defra. The Network brings together research focused on the genetic improvement of leafy vegetables, salads, onion and carrot, and encourages collaborations between industry and researchers to improve crop varieties.

Good breeding

Dr Charlotte Allender, part of the VegIN group and director of the UK Vegetable Genebank explains: “Genetic improvement of vegetable varieties can contribute to a sustainable increase in food production to help meet the twin challenges of food security and climate change.

“Genetic improvement is not genetic engineering. It’s breeding. Our modern crops have been selectively bred, by crossing different varieties to get the best traits – like bigger fruit or quicker growth rates. This has been done slowly over centuries, starting from the original wild plant and ending in what we recognise as the modern crop now. But this process means our crops are not very diverse in terms of genetics. When you choose a plant because it is bigger, you may reduce its ability to suffer frost, flood or insect attack.

“So our crops are generally susceptible to pests and disease, and with greater volumes being produced the requirement for water and fertilizer increases. To accommodate increasing environmental pressure, our current crops will need to be adapted to give higher yields to feed a growing population.

“In crop genetic improvement we aim to address this by using crop genepool diversity conserved in collections like the UK Vegetable Genebank,” she adds.

The UK Vegetable Genebank is a globally significant collection of around 14,000 seed samples of a range of vegetable crops housed at the University of Warwick. The UK Vegetable Genebank has a remit for the collection, conservation, characterization, documentation and study of these vegetable crops and their wild relatives. This seed is also made available to breeders and scientists.

Dr Allender continues: “By looking into the past at older varieties and wild species, we can identify genes and gene combinations that can be introduced into modern crops using conventional breeding techniques, but speeding the whole process up by using cutting edge tools for selection and analysis.

“So where traditional plant breeding used selection based on the appearance (phenotype) of the crop, where the best plants would be kept and used for subsequent crosses, we can now apply modern genetics to select plants based on their DNA profile (genotype). To do this we use molecular markers that indicate the location on chromosomes of small differences in the DNA sequence between individuals. This so-called marker-assisted selection can speed up the breeding process, while saving on costs, and can be more accurate for characteristics that show wide variation depending upon their growth environment.”

Professor Eric Holub is one of the leading BBSRC funded researchers in the area. He explains: “We are currently using biodiversity from plant genebanks and marker-assisted selection to enable mustard crops to defend against a global disease called white rust. Different varieties of mustard are adapted to the climate in different geographic regions for food production. However, we can breed the same disease resistance into these regional varieties. This helps both UK growers to continue producing traditional England mustard and smallholders in India produce their staple crop of oilseed mustard.”

Drilling the beans

So if we can use this technology to improve our existing crops, what about novel crops. Would it be possible to grow a whole raft of newly adapted varieties in the UK in the future?

One project currently underway at Warwick is to develop haricot or common dry bean as a short season pulse crop for UK growers. Professor Holub explains: “We currently consume vast quantities of this pulse in the form of British-style baked beans. However, this popular convenience food is neither baked or British, as it is processed by pressure cooking in a tin from ingredients that are entirely imported from other countries.

“Our aim is to produce haricot bean varieties for UK growers which are better adapted to our climate. So, we’re working to make them less sensitive to cold soil in the spring, resistant to seed transmitted diseases, and ready for harvest in early September. With modern genetic methods, we are improving the ability to select new varieties that combine these key production characteristics for farmers with the culinary properties expected by British consumers.”

Bringing new varieties to market is still quite a slow and steady process which involves evidence-based scientific work as well as large-scale field trials with farmers to see if a new variety has what it takes to be produced on a commercial scale.

So in the meantime, is there anything we can do to stave off a vegetable catastrophe?

“Seasonality will have to come back into play,” concludes Dr Rosemary Collier. “With Brexit pretty much sealed, changes in trade and labour laws on the horizon and seasonal weather changes having such a disastrous and unpredictable effect, we may see certain products becoming too expensive or difficult to supply in the UK in the middle of winter. We may need to return to eating what is in season while we look at improving the production of our most sustainable crops.”

Article source: University of Warwick