The use of forecasting model iMETOS® for strawberry grey mould management

Abstract

Fungicide application according to the recommendations of the forecasting model iMETOS® allows reduction of plant protection costs, especially when the conditions for the spread of diseases are not favourable. Traditionally, management of strawberry (Fragaria × ananassa Duch.) diseases is based on chemical control; however, because of the high cost of pesticides and their adverse environmental effects, it is essential to determine the correct application timing. Disease forecasting models calculate optimal conditions for disease development, therefore model-based applications of fungicides are more precise. This study aimed to evaluate how to apply fungicides more precisely by using grey mould (Botrytis cinerea Pers.: Fr.) risk forecasting model iMETOS® in order to reduce the number of applications, to obtain yield increase and ensure the safety and quality of strawberries. Field experiments were carried out at Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry during 2008–2014 on a strawberry cultivar ‘Elkat’. The experimental treatments were: 1) untreated, 2) conventional disease management system and 3) using forecasting model iMETOS®. The experimental data indicated that the most favourable conditions for the spread of strawberry grey mould occurred in the 3rd–4th week of May and in the 1st week of June. The application time as determined by the forecasting model iMETOS®, gave yield increases in 2008–2014 of 0.9, 9.5, 1.0, 2.8, 4.3 and 3.2 t ha-1, respectively, compared to the control treatment. In 2008–2014, the yield increase in the conventional disease management treatment was 3.2, 7.0, 3.5, 2.8, 2.7 and 2.7 t ha-1 higher compared to the control treatment. In 2009, the yield increases in the iMETOS® treatment were 2.5 t ha-1, in 2013 – 1.6 t ha-1 and in 2014 – 0.5 t ha-1 compared with the conventional disease management treatment. In 2011, there was no yield increase; the yield was similar in both treatments. In the iMETOS® treatments, the amount of rotten fruit was 0.7, 2.3, 0.7, 0.1, 0.2 and 0.6 t ha-1 lower than in the control treatment.