16AGRITECHCAT5: Integrating Control strategies Against soil-borne Rhizoctonia solani in OilSeed rape (ICAROS)

Increased oilseed rape (Brassica napus, OSR) cropping frequency and incidence of soil-borne diseases have been recently identified as major threats and contributory causes to the current 'yield plateau' in UK OSR crops. Rhizoctonia solani, anastomosis group (AG) 2-1 is strongly associated with the presence of its main host, OSR, and the pathogen is implicated in the yield decline of the crop grown with increased frequency in the rotation. Severe damping off disease caused by AG2-1 has been shown to significantly impact on several root system architecture traits of OSR. The epidemiology and control of AG2-1 and Rhizoctonia diseases in UK OSR crops have not previously been investigated.
The aim of this project is to develop new integrative strategies for disease control through work packages designed to i) identify resistance/tolerance traits and novel resistance loci which can be utilised in crop breeding; ii) elucidate disease epidemiology in relation to soil environment and host; iii) quantify yield losses due to damping off diseases caused by R. solani and iv) develop methods for control using varietal resistance and seed treatment for improved disease management and yield of OSR. This project will develop a high-throughput disease screen for phenotyping a range of Brassica napus lines, including conventional varieties, hybrids, diversity sets and mapping populations to identify novel loci for resistance against R. solani. Future strategies for effective disease management will be established through multidisciplinary studies integrating disease modelling, computed tomography and molecular biology to determine the epidemiology of R. solani in relation to its host and the environment, quantify yield losses and determine responses to seed treatment for Rhizoctonia disease. A major output at completion will be integrated guidelines incorporating novel seed treatments and varietal resistance/tolerance for improved disease management and protection of OSR yield.

Increased oilseed rape (Brassica napus, OSR) cropping frequency and incidence of soil-borne diseases have been recently identified as major threats and contributory causes to the current 'yield plateau' in UK OSR crops. Rhizoctonia solani, anastomosis group (AG) 2-1 is strongly associated with the presence of its main host, OSR, and the pathogen is implicated in the yield decline of the crop grown with increased frequency in the rotation. Severe damping off disease caused by AG2-1 has been shown to significantly impact on several root system architecture traits of OSR. The epidemiology and control of AG2-1 and Rhizoctonia diseases in UK OSR crops have not previously been investigated.
The aim of this project is to develop new integrative strategies for disease control through work packages designed to i) identify resistance/tolerance traits and novel resistance loci which can be utilised in crop breeding; ii) elucidate disease epidemiology in relation to soil environment and host; iii) quantify yield losses due to damping off diseases caused by R. solani and iv) develop methods for control using varietal resistance and seed treatment for improved disease management and yield of OSR. This project will develop a high-throughput disease screen for phenotyping a range of Brassica napus lines, including conventional varieties, hybrids, diversity sets and mapping populations to identify novel loci for resistance against R. solani. Future strategies for effective disease management will be established through multidisciplinary studies integrating disease modelling, computed tomography and molecular biology to determine the epidemiology of R. solani in relation to its host and the environment, quantify yield losses and determine responses to seed treatment for Rhizoctonia disease. A major output at completion will be integrated guidelines incorporating novel seed treatments and varietal resistance/tolerance for improved disease management and protection of OSR yield.

Control of Rhizoctonia diseases in oilseed rape (OSR) is currently only possible through the exclusive use of fungicides, which increases input costs and is unsustainable crop management practice in the long term. Furthermore, there are currently no seed treatments registered against Rhizoctonia diseases in UK OSR, highlighting the lack of information on yield loss and contribution of the disease to current establishment losses estimated at £30M in the worst years. The ultimate economic impact of the project will be the recovery of loss in establishment failure or yield due the disease through improved control strategies thus stabilising farming incomes. The ultimate impact is envisaged as increased competitiveness of UK OSR industry through acceleration of novel trait discovery such as disease resistance/tolerance to R. solani realised through commercial crop breeding and benefiting UK OSR production. The identification of novel resistance or tolerance traits and genes in OSR against R. solani, AG 2-1 will allow integration with more targeted crop protection approaches such as low dose seed treatment.
Expected environmental impact of this project is to rationalise the use, effectiveness and response to seed treatments in OSR varieties against damping off disease caused by R. solani and avoid the use of unnecessary or ineffective fungicide treatment where varietal resistance/tolerance can be deployed. Protecting the root system of OSR during establishment should result in lower greenhouse gas emissions and minimise nitrate leaching through more effective nutrient and water uptake by the crop and improved yield.
Improved yield protection in OSR will be crucial to meet production demand whilst minimising pressure for land use change and maintaining food security. Achieving effective control of soil-borne disease such as Rhzoctonia on currently utilised land for crop production will allow land use diversification thus increasing overall biodiversity.