No abstract

No abstract

Potatoes were planted 19 May, at the University of Minnesota Northwest Experiment Station, Crookston, MN and the Red River Valley Potato Growers Association Research Farm, Grand Forks, ND. Research plots were of variable length with 36-inch row spacing, randomized in complete blocks with 3 replications. Pretreatment counts were made by counting all 2nd through 4th instar larvae on sufficient plants to yield a minimum of 200 larvae per replication. One insecticide spray was applied 30 Jun, with a C02 powered hand sprayer deUvering 36 gal of water/acre. Percent control was based on pretreatment counts for the first evaluation, and in comparison to the untreated control plots for the second evaluation.

Potatoes were planted 24 May, at the University of Minnesota Agricultural Experiment Station, Rosemount MN. Plots were 40 ft long, with 40 inch row spacing, randomized in complete blocks with 3 replications. Insect numbers were estimated by counting nymphs on the underside of 30 leaves per plot. Foliar sprays were applied using a C02 powered hand-sprayer delivering 36 gal of water/acre at 35 psi. Treatments were applied 27 Jul, and evaluations were made 7 days posttreatment.

Potatoes were planted 18 May, at the Red River Valley Potato Growers Research Farm (RRVPGA), Grand Forks, ND. Plots were of variable length with 38-inch row spacing, randomized in complete blocks with 3 replications. All beetle larvae were counted on every plant in each replication until a minimum of 200 larvae were found. Insecticide treatments were applied using a CO2 powered hand-sprayer delivering 50 gal water/acre at 35 psi. Treatments were applied 7 Jul and evaluated 24 h later on 8 Jul. Subsequent evaluations were not possible because of the aerial application of insecticide to the entire field on 9 Jul.