Sustainable strawberry production including the use of a rule based prediction system for controlling Strawberry Powdery Mildew

Abstract

UK strawberry production could be viewed as an example of sustainable intensification through the precision use of varieties, nutrients and polythene tunnels. Powdery mildew, Podosphaera aphanis, is a major fungal disease affecting strawberry production worldwide. Serious epidemics can reduce crop yields for up to 70% as a result of inadequate ripening of fruits, fruit deformation, poor flavour development and reduced storage time. The pathogen infects strawberries in nearly all organs and is specific to this crop. A rule based prediction system based on temperature and humidity has been developed to predict High Risk Days to alert the grower when fungicide spraying is necessary. A field trial was carried out under a tunnel growing strawberries at a commercial farm in 2013 aimed to assess the efficacy of the prediction system on disease control. Weekly disease assessments were carried out from April to June. Results suggested that though the disease was reduced by spraying with fungicides, there were considerable differences between beds in the tunnel, which should be partly explained by differentiations of micro-climate between beds. The study also calculated Greenhouse Gas (GHG) emissions of all pesticides used in the tunnel. Fungicides represented the largest contribution to GHG emissions. Results shows that Fenomenal and Trianosan DG produce higher level of GHG emissions compared to the other fungicides used. The hypothesis is that use of a precision prediction system would enable disease control with fewer fungicide sprays, thus reducing overall GHG emission.