Suppression of Flea Beetles in Canola, 1992

Canola plots were established at the MSU Hort Farm in Bozeman, MT. Two tests measuring 10 x 30 ft, were planted on 3 Jun. Insecticides were applied on 18 Jun with a CO2-powered backpack sprayer calibrated to deliver 10.5 gal/acre at 20 psi. The hand held spray boom had Teejet 8001 flat fan nozzles and a 10 ft spray swath. Treatments were arranged in a randomized complete block with 3 replicates per treatment. Treatments were evaluated by assessing FB plant damage using a numerical rating of 0 to 6, where 0 = no damage, 1 = minor leaf abrasion, 2 = 1-3 shot holes with some pitting, 3 = 3-5 shot holes with 25% of cotyledon destroyed, 4 = 5-10 shot holes with 25-50% of the cotyledon destroyed, 5 = > 50% of cotyledon destroyed, and 6 = no cotyledons. In test 1, pre- and posttreatment ratings were made by randomly selecting 10 plants in each replicate. In test 2, 10 plants in each replicate showing minimal FB damage were flagged shortly after emergence and rated prior to treatment and each selected DAT. Data were analyzed using ANOVA and means separated by LSD test.