TY - JOUR T1 - Flower Debris Removal Delays Grape Bunch Rot Epidemic JF - American Journal of Enology and Viticulture JO - Am. J. Enol. Vitic. DO - 10.5344/ajev.2015.15019 SP - ajev.2015.15019 AU - Daniel Molitor AU - Lucien Hoffmann AU - Marco Beyer Y1 - 2015/06/19 UR - http://www.ajevonline.org/content/early/2015/08/04/ajev.2015.15019.abstract N2 - Field trials investigating the impact of removing flower debris (necrotic flower caps, filaments, anthers, aborted unfertilized ovaries, aborted berries), which usually remain partly attached to grape clusters after bloom, on the epidemic of grape bunch rot caused by Botrytis cinerea were conducted in the white Vitis vinifera cultivars Pinot gris (four experiments) and Riesling (two experiments) in Luxembourg in the years 2011 to 2014. Grape clusters remained either untreated (control), flower debris was removed from the clusters (brush), clusters were treated with a botryticide (active ingredient fenhexamid) botryticide) or clusters were brushed with a brush soaked in a botryticide suspension (botryticide-soaked brush) at growth stage BBCH 73. On average for all six trials, bunch rot epidemics (day of the year when a disease severity level of 5% was reached) were significantly (p < 0.045) delayed compared to the untreated control by 3.7 (brush), 4.3 (botryticide) or 5.7 (botryticide-soaked brush) days, respectively; whereas no significant differences (concerning the delay of the epidemic) were observed between the three treatments. Consequently, flower debris removal might contribute to a reduction or partial replacement of pesticide use in viticulture. Efficient technical solutions to automatically remove flower debris need to be developed. ER -