ISCF WAVE 1 AGRI TECH Development of a diagnostic tool to assess risk levels of pea foot rot pathogens in soils

Foot rot diseases in pea crops cause root and stem rots which result in substantial yield losses and reduction in the quality of the peas, decreasing their value by £12.5M per annum. The diseases are caused by several soilborne pathogens which cannot be controlled with fungicides, and severity of losses is determined by pathogen levels in soils, soil structure and weather conditions. Currently crop rotations whereby peas are not grown for several years are the only means of mitigating the problem. However, measuring pathogen levels in soil before planting peas holds the potential to identify fields where disease risk is low. This project will develop molecular tools to quantify foot rot pathogens in soils and link levels to potential yield loss. This will provide a risk assessment tool for pea growers helping them to choose fields with healthy soils for growing high quality peas. Efficiency of pea production in the UK will be increased and the use of land, water, energy and fertilisers will be reduced.

Peas are valuable crops for the environment, crop rotation, diet and human health. Production in the UK is worth £69M but is severely threatened with yield decline due to footrot pathogens which include Fusarium oxysporum f.sp pisi, Fusarium solani f.sp pisi, Didymella pinodella and Aphanomyces euteiches. This costs the industry £12.5M per annum and the situation is exacerbated by the fact that frozen peas are grown in restricted areas due to climate and the need to be close to processing facilities. Mitigation of footrot is limited to rotational planning but yield losses could be further avoided by quantification of pathogen levels before planting. Although PGRO already offer soil tests for F. solani, D. pinodella and A. euteiches, these are based on morphological identification of fungal colonies on agar or on disease symptoms on pea roots and hence are time consuming, expensive and prone to error. The main aim of this project is to develop molecular diagnostic tools to assess risk of foot rot disease development in pea crops. This will involve developing quantitative PCR tests for the main foot rot pathogens, optimising DNA extraction protocols from soil and relating qPCR test results to disease levels and pea yields. This will allow PGRO to offer new commercial tests providing a rapid, reliable and accurate test for multiple footrot pathogens and an increased estimated income of £5,000-10,000 per annum. Growers will benefit from a cheaper, more efficient and accurate service that will enable more precise assessment of disease potential in field. This will result in more efficient rotations and greater sustainability and economic returns for the UK pea industry. The approaches taken and the protocols developed will benefit work on detection/quantification of soilborne plant pathogens in other cropping systems. The project brings together a multidisciplinary team comprising PGRO and academics with expertise in fungal biology and molecular diagnostics.

This project aims to help alleviate the severe decline in UK pea yields caused by the increased prevalence of the footrot complex of soilborne plant pathogens through the provision of rapid, accurate and quantitative molecular soil tests. The UK produced 148,700 tons of frozen peas in 2015 (Source: British Growers Association) worth £44.6M and 176,000 tons (Source: Eurostat) of combinable peas worth £24.64M per annum (at current prices) and, depending on disease pressure, soil conditions and weather, yield decline losses are estimated at a minimum of £12.5M per annum. Mitigation is limited to crop rotation strategies and hence knowledge of pathogen soil inoculum potential and associated predicted yield losses would greatly improve this approach. The corresponding reduction in yield decline will have a major economic impact and safeguard against further decline of UK pea yields. One of the main beneficiaries of this research will be PGRO, as they will have access to new tools to better identify/quantify the presence of footrot pathogens on behalf of growers. These tests will be faster, more reliable and cheaper generating an increased estimated income of £5,000-10,000 per annum for PGRO. The other major beneficiary will be pea growers who will benefit from a cheaper, more accurate and wide-ranging foot rot test. This will save them approximately £72 per sample which equates to £21,600 per annum for the ten major grower groups. However, the major benefit will be in allowing the growers to make much better informed decisions about their rotations and which fields have the lowest risk of disease when they plant. This will lead to increased yield, less waste and decreased economic losses through the overall reduction in disease as well as more even maturity at harvest and more reliable factory throughput. Following the project, pea growers will therefore be able to maintain and potentially increase production for both home and export consumption with associated economic benefits.