PT  - JOURNAL ARTICLE
AU  - Daniel Molitor
AU  - Lucien Hoffmann
AU  - Marco Beyer
TI  - Flower Debris Removal Delays Grape Bunch Rot Epidemic
AID  - 10.5344/ajev.2015.15019
DP  - 2015 Jun 19
TA  - American Journal of Enology and Viticulture
PG  - ajev.2015.15019
4099  - http://www.ajevonline.org/content/early/2015/06/12/ajev.2015.15019.short
4100  - http://www.ajevonline.org/content/early/2015/06/12/ajev.2015.15019.full
AB  - 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.