Late Season Insect Control in Canola, 1993A

A large block was seeded on 7 inch centers at 7 lb/acre using a plot drill on 11 May at the University of Idaho Plant Science Farm in Moscow, ID. Individual 12 × 23 ft plots were later tilled-out of the block. Insecticide treatments were arranged in a RCBD with 4 replications each. Treatments were applied on 27 Jul when about 10% of the plants were still in bloom. Temperatures at the time of spray application were 82°F. Insecticides were applied using a CO2-pressurized backpack sprayer equipped with 80° fan nozzles on a 6-ft boom that delivered 20 gal/acre at 20 psi. Pretreatment and posttreatment counts of DBM were made by dislodging larvae into a 5 gal plastic bucket with a beat of the hand at each end of the plot. The proportion of aphid-infested canola terminals was assessed by randomly selecting 50 terminals in each plot and recording the presence or absence of aphids. Plot yields were obtained by making one pass along the center of each plot with a smallplot combine (4.6 ft header). Seed was cleaned and weighed. All data were subjected to analysis of variance and protected LSD tests.