The effect of spray volume and quality on handgun delivery of pesticides to greenhouse plants

Abstract

Greenhouse pesticide labels lack specific recommendations on the spray volume and spray droplet sizes which will provide the most efficacious pest management. A greenhouse trial was established to determine differences in spray retention in a poinsettia canopy between applications using three different spray volumes and three different spray qualities using single nozzle handgun applicators. For the same areas of the canopy, there were few differences in spray deposit between treatments. Fronts and upper areas of the canopy received more deposits than the backs and lower areas of the canopy. There were no significant differences in recovery of fungicide from leaves between treatments. The high volume application produced the highest deposits on artificial targets across all spray qualities. There were no significant differences in overall spray deposit between the low and medium volume treatments.