2018 ASHS Annual Conference

Botrytis cinerea is a large problem during cut rose production and in the postharvest environment. Cultural practices that take place during rose production in greenhouses can lead to spore dispersal that increases the infection risk. The objective of this research was to evaluate the relationship between Botrytis spore density and cultural practices in commercial greenhouses of cut rose production, additionally changes on Botrytis spore density were evaluated across weeks. To achieve this, two spore samplers were placed in commercial greenhouses to collect daily air samples, and a daily report of all the cultural practices performed at the greenhouse was obtained. After 300 days of data collection, analysis of variance was used to determine the correlation between each cultural practice on the Botrytis spore density. The results showed that mechanical removal of plant debris from the rose canopy, plant growth regulator application (which involves removal of plant debris from the surface of the growing media, movement of the top layer of growing media, and drench application of the growth regulator), sweeping of floors, realigning the canopy (returning errant shoots to the plant canopy) and harvesting were more closely correlated to the spore density data. Variations on the spore density were determined between weeks. Additionally, Wednesday, Thursday and Friday (days with more cultural practices) presented a consistently higher spore density while Sunday (day with the less or none cultural practices) showed the significantly lowest spore density.