Spray Application Problems: LXXVII Insecticide Spraying Trials in Willow Beds Using a Shoulder-Mounted Mistblower

Abstract

The following is virtually the authors' summary. The performance of a shoulder-mounted mistblower fitted with a double nozzle was examined in south-western England for applying insecticides on basket willows. An operator can spray 10 acres per day, applying 3 gal. spray per acre, by walking at 2-3 miles per hour through each tenth row. Dilute sprays containing a mixture of 0.0216 % γ BHC and 0.025 % DDT and concentrated ones containing 0.108 and 0.125%, respectively, gave moderate control of aphids, of which the principal species on willow are Aphis farinosa Gmel., Cavariella pastinacae (L.) and Pterocomma pilosum Buckt. Control of the willow leaf beetle (Pyrrhalta (Galerucelld) lineola (F.)) was satisfactory at both concentrations if the spray was applied more than once. A single spray applied at the beginning of July gave control for about three weeks. It is essential that the beetle should be controlled at the beginning of the infestation, and the results suggest that two sprays a fortnight apart may provide adequate protection. The proportion of clean straight rods in the sprayed blocks was double that in the unsprayed one.