Control of Alfalfa Looper Larvae on Pea, 1975

All insecticides were applied at 4.2 kg/cm2 (air pressure) and 380 l/ha through D2-13 “TEEJET” hollowcone nozzles mounted 28 cm apart on a rear-mounted boom sprayer fitted to a JD-420 tractor travelling at 4.4 km/hr. The boom height was adjusted to provide maximum coverage of the foliage as the plants grew. There were 4 replications of each treatment. Treatments were applied to 1.5 x 6 m, 8-row beds (18 cm interrow spacing). The crop was planted on April 2 and was sprinkler irrigated (2.5 cm/irrigation) weekly until June 1. Treating was begun on May 30. Temperatures ranged from 10 to 30°C during the test period. The afternoon prior to each treatment, two, 1.2 x 1.5 m sites at the ends of each bed were stocked with 2nd to 5th stage larvae from the laboratory culture to ensure populations of uniform size and stage. The percentage control obtained at harvest on June 15 was determined by cutting and examining the foliage, and the soil beneath at each site.