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Relationship between cereal disease resistance ratings and disease yield loss and its use a tool in VCU evaluation - VS0121

consideration of a candidate cereal variety`s disease resistance is a major factor in the decision to accept or reject it for national listing. This reflects the national importance attached to reducing fungicide inputs by a gradual improvement in the genetic disease resistance of varieties available to UK farmners. In reaching its decisions, the NL Commitee has to take a balanced view of the agronomic characters of a candidate in relation to varieties already on the list. For disease resistance, there is currently no objective means of weighting ratings; for example, to address the question of whether a rating of 3 should be regarded as an equivalent weakness for both mildew and septoria, or whether one should carry more weight than the other.
VCU and RL trials provide a balanced set of fungicide-treated and untreated trials. Fungicide treated trials give an estimate of the ield when disease is allowed to develop freely. The difference in yield between treated and untreated trials indicates the yield at risk from disease, which varies between varieties according to their disease resistance and the diseases present in the trials. Preliminary invetigations of the VCU/RL database have already provided evidence that the relationship between disease resistance rating and "yield at risk" varies distinctly between diseases. For example, a rating of 3 for wheat mildew is associated with yield loss of around 10%, whereas the same rating for septoria has a "yield risk equivilant" of nearer 25%. This suggests that a rating of 3 for Septoria might justifiably be regarded as a greater weekness than the same rating for mildew.
this proposal is to investigate the trials database to establish yield risk equivilants for resistance ratings for all major diseases of all ceral crops. these will provide an objective basis for weighting disease resistance ratings, thereby assisting NL decision-making by providing a quantifiable basis for evaluating varietal strengths and weeknesses in disease resistance.
1. To assess the suitability if a range of statistical methods for this application.
2. To investigate relationships between varietal disease resistance and yield loss due to disease, using data from VCU.RL cereal variety trials.
3. To establish yield risk equivalents for disease resistance ratings for all major diseases of all cereal crops.
4. To make recommendations for the use of yield risk equivalents in NL decision-making.
Project Documents
• Final Report : Relationship between cereal disease resistance ratings and disease yield loss and its use a tool in VCU evaluation   (8284k)
Time-Scale and Cost
From: 2001

To: 2001

Cost: £25,469
Contractor / Funded Organisations
National Institute of Agricultural Botany
Crop Diseases              
Plant Varieties and Seeds              
Plants and Animals              
Variety Testing              
Fields of Study
Plant Varieties and Seeds