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This was a cooperative study with Agrigenetics on their research station at Breckinridge, MN. Coated seed was made available from Grow Tec, Ltd in Nisku, Alberta, Canada. Plots were established in clay type soils and individual plots were 6 rows, 0.9 m on center, 6.10 m in length. Treatments were replicated 4 times, in a randomized complete block. Granular applications were mixed with the seed and planted on Apr 30. The at-plant broadcast liquids were applied immediately post plant and raked in lightly. First foliar applications at germination were made on 21 May. Uneven germination made it difficult to properly time these applications. Final foliar applications were made on 16 Jul.

Certified B-size potatoes were planted 21 May at the University of Minnesota Agricultural Experiment Station, Rosemount. The field, a Waukegan silt loam, had been in soybeans the previous year. Treatments were 2 rows, 40 ft long with 40-inch row spacing. Treatments were randomized in complete blocks with 4 replications. Granular insecticides were applied at planting in furrow with a planter-mounted granular applicator and at emergence over the rows on 2 Jul and sidedressed on 23 Jul. An additional treatment consisted of 3 foliar sprays of Pydrin at 0.1 lb/acre on 16 Jul, 15 Aug, and 30 Aug. Plots were evaluated by counting CPB larvae by instar on 10 randomly selected plants in each plot on 7 Jul, 28 Jul, 11 Aug, 18 Aug, 23 Aug, 31 Aug, and 9 Sep. Plots were also evaluated for PLH by sampling 35 mid-plant leaves in each plot. Temik and Thimet plots were not sprayed with any foliar insecticide. On 15 Oct potatoes were harvested and sorted by grade. Two-way ANOVA was used to test for treatment differences in PLH and CPB densities.

An irrigated trial was located in a commercial field at Kay Farms near Brooten, Minn. The field was planted 22 Apr with a 6-row commercial planter. Insecticide applicators were disconnected while the experimental area was being planted and then reconnected to complete field rows. The main field was treated with 3 lb (AI)/ acre of Thimet. Fertilizer, weed control, etc., were constant throughout the experimental and production field. Plots were 4 38-inch rows 30 ft long, replicated 3 times, and arranged in a randomized complete block design. The plot area was located 6 rows from the pivot road and extended 150 ft from the field edge into the main field. The soil was a sandy loam. At-plant treatments were applied on 23 Apr and lightly covered. Emergence treatments were applied 20 May. Foliars were applied on 22 Jun, 10 and 22 Jul, and 10 and 20 Aug. Foliars following emergence granular applications were applied on 3 and 22 Jul. Foliars were applied using a hand-held CO2 sprayer using 40 psi pressure and 12 gal total material/acre. Yields were taken by digging the 2 center plot rows, grading into #ls and B-size, and recording.

‘C-elete’ lima beans were planted 1 to 1.5 inches deep, in single row plots, 17 ft in length and 6 ft in width, on Jul 16. The treatments were arranged in a randomized split block design with 3 replications. The insecticide treatments were applied at planting time with a single spout electric drive Gandy (Model 901-2). Sidedress treatments were applied 2 inches to the side of the row and 2 inches below the seed. Dribble treatments were allowed to flow freely from the tube directly over the row behind the furrow press - wheel and followed by a drag chain. Band treatments were applied in a 6 inch wide band over the row behind the furrow press - wheel and followed by a drag chain.

The trial was located at the Northwest Experiment Station, Crookston, Minn. The major objective of the 1987 insecticide trials was to compare at-plant-and-time-of-emergence soil systemic treatments in dryland sites (Crookston, Minn., and Grand Forks, N. Dak.) and irrigated locations (Park Rapids and Brooten, Minn.). Soil systemic treatments were present at each site with various combinations of foliars. CPB are at least 100-fold resistant to Pydrin and 40-fold resistant to Ambush + Pounce at this location. Plots were 4 40-inch rows 25 ft long. Treatments were replicated 4 times and were arranged in a randomized complete block design. B-size Norchip seed was planted on 5 May and planting treatments of Temik and Thimet applied over the row. The soil was a clay type, permitting granules to fall into soil openings along the planting ridge. Soil moisture was very good. Emergence treatments were applied on 29 May when potato plants were 2 inches high. Soil was cultivated over the emergence treatment. Wintering CPB adults were present in higher than normal numbers on this date. Foliars were applied on 20 and 28 Jun, 10 and 22 Jul, and 8 Aug according to an experimental plan of 1, 3, and 5 foliars. Foliars applied over the emergence soil systemic were applied 20 Jun and 8 Aug. Adult emergence from an adjacent potato plot threatened to overwhelm these studies in July (note adult defoliation column in table). Thus, we waited for modest second-generation oviposition and then treated the entire study with 0.5 lb (AI)/acre of Penncap-M on 24 Jul. Three applications of fungicide were applied independently of insecticides. Yields were taken from the center 2 plot rows, graded #1 and B-size, weighed, and recorded.