For the good of our health - and that of the planet - we should eat more pulses.
Last year the EAT-Lancet Commission on Food, Plant and Health recommended that dried legumes such as beans, peas and lentils should feature more as an essential part of a healthier diet which will also help us improve the future sustainability of our planet. But where would the increased supply of pulses for UK consumers come from? Our favourite pulse, the common dry bean or haricot bean, is imported because the current commercial varieties are poorly adapted for growing as a crop in the UK climate. But now, thanks to scientists working at the University of Warwick’s Wellesbourne campus, there’s hope for change.
In late summer 2019, a combine harvester took in the first food production trial of a new variety of haricot bean developed by a team scientists – past and present – at the University of Warwick’s Crop Centre, part of its School of Life Sciences. The white bean, named Capulet, was grown in a mixed crop with a large yellow-brown heritage variety. Both varieties are adapted to grow especially well in UK conditions.
Why is this exciting? Well, white haricot beans are probably lurking in every kitchen cupboard in Britain as they are the main ingredient in the nation’s favourite comfort food and emergency tea – baked beans. Although more than two million tins are opened in Britain every day, none of the beans in the big brands are grown by UK farmers. They are imported entirely from the US, Canada, Ethiopia and China.
Now, new varieties of haricot bean are being bred to grow successfully in British sunlight – with a vision to take these home-grown beans beyond the can.
Investing in beans
The research into developing a variety of white haricot bean that was suitable for growing and canning in the UK started in the 70s and 80s. The Ministry of Agriculture Food and Fisheries (MAFF) funded a team of scientists at Wellesbourne, formerly the National Vegetable Research Station, to investigate the physiology, pathology and agronomy of haricot beans to underpin breeding of varieties for UK farmers.
By the mid-1980s, three varieties were produced, named Edmund, Marcus and Adrian after Shakespeare characters. Edmund was Nationally Listed for UK farmers, and grown in field-scale trials across England. But at this time the fledgling pulse crop could not compete with pressures from commodity market pricing, and concern about climate change and healthier eating were largely unrecognised by governments and society as a whole. As a consequence, investment for UK haricot bean research fell away and the project material was put into cold storage.
But in 2011, Professor Eric Holub from Warwick’s Life Sciences department resurrected the NVRS research programme and began evaluating stored seed material with a renewed perspective.
A ‘millenial’ white haricot bean
Professor Holub explains: “I began by talking with the retired NVRS scientists, and then deciding how we could build on their previous work by thinking about the versatility of haricot beans outside of the tin and ‘beyond beans on toast’. Our first step was to evaluate potentially better breeding lines that were generated in the late-80s using Edmund as one of the two parents. One descendent line stood out. It looks like Edmund as a bean and retained its resistance to three common seed transmitted diseases, but was more erect as a plant and importantly is ready to harvest seven to ten days earlier. Keeping with the Shakespeare theme, we named it Capulet.”
In 2015, a seed sample of Capulet was sent to the European facility in Germany for common bean variety testing, and in 2018 it received approval for registration and National Listing as a new variety for UK farmers.
A low-input crop in British sunshine
Disease resistance in Capulet is important to reduce the need for chemical control of harmful microbes. Harnessing beneficial microbes is also important, especially for legumes. In 2018, Holub’s team discovered a useful bacterium in root nodules of beans from their field trial, possibly surviving in the soil since the last NVRS field trial in 1987 of Rhizobium-inoculated beans. Rhizobium resides in root nodules and helps a legume like haricot beans to capture nitrogen from air and fix into a biologically essential form used in amino acids. This beneficial symbiosis can reduce the need for application of fertilizer and help improve soil nutrition.
Another advantage of Capulet is that it makes efficient use of British sunshine. It can be drilled in early May and harvested as a dry grain before the middle of September. In the hot summer of 2018, Capulet was ready to harvest from one field trial by mid-August - just 97 days after drilling. This is important for UK farmers, as a short season legume would provide an excellent break crop option in between growing cereals.
Last year, with the help of tenant farmer, Derrick Clarke, the first food production trial of Capulet was grown and harvested at the Warwick Crop Centre farm on the University’s Wellesbourne Campus. Professor Holub explains:
“We drilled the crop in the first week of May and harvested dry beans in mid-September using Derrick’s conventional combine harvester. We added another bean variety as a mixture with Capulet because it’s slightly taller and sturdier. We harvested nearly four tonnes of beans from the 1.6 hectare field. There’s room for improvement but it’s a promising first attempt.”
The team is now working with an agronomy partner to work on scaling up production of Capulet as a single commercial crop for UK farmers for the British market. They have also sent off two new lines (a blonde-coloured bean called Godiva, and a black bean called Olivia) for evaluation to register as new varieties.
Towards a healthier British diet
Last summer’s harvest was the first of a sufficient quantity which now enables Professor Holub to start to work with local community cafeterias and restaurants. A PhD researcher, Rosanne Maguire, is working with him on understanding consumer interest for using haricot beans as an ingredient for different uses in the British diet.
Professor Holub explains: “It’s clear that we need to think collectively as a society about self-sufficiency and our ability to feed ourselves. With this in mind, we launched an initiative called 2Bhealthy in a Greener Britain.
“The aim is to help us build a wider narrative for using home-grown ingredients in a healthier British diet that includes eating British-grown pulses. Haricot beans are already our favourite pulse in the form of canned baked beans, but their versatility means we can fill another place in our diet alongside other British vegetables and fruit, cereals, and high quality animal-based products like dairy, eggs and meat.
“All of the beans that we are breeding for UK production will be fast cooking. They only need to soak for about an hour – so when you make a cup of tea in the morning you can pour boiling water on the beans. After they are soaked it takes just 15 mins of boiling to cook them. Compare this to a kidney bean for example, which will take an hour and a half cooking before it starts to get soft.
“After that there is an endless range of food choices. I love them in a bean mash – like refried beans, cooked with British beer or cider. They are also great in blended soup or as whole beans in a casserole.
“Ultimately, it’s about adding a missing ingredient to our diet of British produce. Haricot beans can add more prebiotic dietary fibre, more iron and more protein as our society’s diet shifts to become more plant-based.
"The time is right for us to really start investing in a novel British pulse crop, with people looking more actively at their diet and also their own impact on climate. Varieties like Capulet provide a good option for British farmers, benefiting the nation’s soil and providing a tasty and healthy plant protein for British consumers."
6 February 2020
Professor Eric Holub trained in legume pathology and plant breeding in the US, completing research that catalysed a public-commercial partnership with regional seed companies for release of multiple disease resistance in alfalfa forage varieties. His interests in tackling challenges of food insecurity includes research to improve disease resistance in brassicas and the haricot bean research programme, working to adapt this crop for UK production.
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