Potatoes were planted 24 Apr at the MSU Montcalm Potato Research Farm. Plots were 3 rows wide (34-inch row spacing) by 40 ft long. Two unsampled rows were left between adjacent plots. Treatments were arranged in a randomized complete block design with 4 blocks per treatment. Treatments were applied as foliar sprays with a tractor-mounted boom sprayer at 30 gal/acre, 40 psi, with a cluster of 3 nozzles over each row. The middle nozzle directed spray down over the top of the plant, and the other nozzles directed the spray at the sides of the plant. Treatments for control of first-generation Colorado potato beetle were applied on 15 and 22 Jun (with the exception of the DPX-EY059 treatment, which was applied only on the first date). Insects were counted on 10 Jun (pretreatment count), 18 Jun (after first treatment), and 25 Jun (after second treatment). Randomly selected plants from the middle row of each plot were sampled (3 plants/plot on the first date; 2 plants/plot for each of the postspray dates). Damage ratings per plot and plant (2 plants per plot) were made on 25 Jun. Damage ratings were based on a scale of 1 to 5, where 1 indicated no damage (per plant or per plot), 2 indicated 0-5% defoliation (per plant or per plot), 3 indicated 5-25% defoliation, 4 indicated 25-50% defoliation, and 5 indicated 50-100% defoliation. Beetle numbers were low in first-generation plots on 25 Jun, but rose sharply again in July (due to emergence of second-generation beetles). To maintain differences in yield and foliage damage levels due to first generation beetles, these plots were sprayed with Furadan 4F (1 lb [AI]/acre) on 16 Jul and again on 18 Aug. Damage ratings were again taken of first-generation plots on a per-plot basis on 28 Jul (about 1 mo after last treatment application). New growth of badly damaged plants had made the previously used damage scale unusable, so damage ratings were made on the basis of percentage of soil visible in plots (1, no soil visible—least damage; 2, 1-5% of soil visible; 3, 5-25% of soil visible; 4, 25-50% soil visible; and 5, 50-100% of soil visible— most damage). Treatments for control of second-generation Colorado potato beetle were applied on 17 Jul and 17 and 23 Jul (again, with the exception of the DPX-EY059 treatment, which was applied only on the first date). Insects were counted on 2 randomly selected plants from the middle row of each plot on 14 Jul (pretreatment count), 21 Jul (after first treatment), and 28 Jul (after second treatment). Furadan 4F was sprayed on second-generation plots on 23 Jun to suppress first-generation beetles. Nonetheless, damage occurred to these plots before treatments were applied. To check for significant differences in damage between plots before the first treatment, a plot damage rating was made on 14 Jun. Damage ratings were also made on a per-plot and per-plant basis, according to the scale described previously, on 28 Jul (after second treatment). Furadan 4F was again sprayed on all second-generation plots on 18 Aug. Potatoes were harvested from middle row of each plot and weighed (first- and second-generation plots) on 7 Oct. Data (insect numbers, damage ratings, and harvest weight) were analyzed by a two-way analysis of variance at P = 0.05. Tukey's test was used to test for nonadditivity. Multiple comparisons (SNK) were made where significant results were obtained.
Green bell peppers (var. KRG-3) and sweet banana peppers (open pollinated) were transplanted as separate trials on 29 May at the MSU Entomology Field Research Farm, East Lansing. Plots were 3 rows wide (30 inches between rows) by 30 ft long (18 inches between plants) arranged in a completely randomized design with 4 replications. Treatments were applied with a tractor-mounted boom sprayer at 30 gal/ acre and 40 psi on 22 and 29 Jul and 4 Aug. Two plants from the center row of each plot were examined on a weekly basis for European corn borer (ECB) egg masses and green peach aphids (GPA). Banana and bell peppers were harvested on 10 and 11 Aug, respectively. All fruit from 27 ft of the center row were harvested (a subset of 40 banana peppers were randomly selected) and examined for ECB damage. On 11 Aug, 4 leaves per plant (4 plants per plot) were examined for GPA.
Onions were planted at the M.S.U. Muck Research Farm, Bath, Mich. Plots were single rows (17 inches between rows) 20 ft long, arranged in a randomized complete block design with 4 replicates. Two border rows were left unsprayed between each plot. Treatments were applied with a single-nozzle (D4) hand-held CO2 sprayer at 40 psi. The gallonage varied according to treatment (see table). Sprays were applied 8 and 12 Aug. Before treatments were applied on 8 Aug and then posttreatment on 15 Aug, 20 plants per plot were randomly selected, cut off at the base, and rinsed with 75% ethanol. The rinsate (with thrips) was collected in a cup, filtered through a Buchner funnel onto filter paper, and the number of thrips counted.
Onions were seeded at Brink Muck Farms, Grant MI on 22 Apr. Plots were single rows by 20 ft, arranged in a completely randomized block design with 4 replications per treatment. Granular insecticide treatments were applied with a standard v-belt seeder during seeding. Other plots were seeded with a Planet Jr. seeder (same planting shoe and depth as the v-belt seeder). The at-planting liquid Lorsban treatment was applied in the seed furrow, prior to seeding. Soil drench treatments were applied in a 2 to 3-inch band over the row at 50 gal of water per acre with a hand sprayer. Applications were made weekly (except for Lorsban and certain ABG-6178 treatments), beginning at first signs of oviposition and damage and continuing to the end of oviposition (15, 22, 29 May; 5, 12, 19, and 26 Jun). This was 2 wksor so longer than in 1983 or 1984, due to the early spring and long oviposition period. One hundred plants per plot were staked off immediately after plant emergence and checked weekly for onion maggot damage, 22 May through 2 Jul. Percent stand remaining after first generation damage was assessed from these same plants on 9 Jul. Harvest data was not taken since plant stands were not identical between v-belt and Planet Jr. seeded plots. Identical plots were established at the M.S.U. Muck Crops Experimental Farm, but damage in untreated plots (and other untreated areas on the farm) was less than 5% and no treatment differences occurred.
Cabbage was transplanted at the MSU entomology research farm on 18 Jun. Plots were 3 rows wide (30-inch spacing) and 20 ft long (18 inches between plants in row). Plots were separated by 10 ft at row ends; 8 ft between rows. Starter fertilizer was added at transplant; a Lorsban drench (3.3 oz/1000-ft row) was applied 20 Jun to control cabbage maggot. Treatments were arranged in a completely randomized design with 4 replications per treatment. Weekly treatments were applied from 14 Jul to 20 Aug. Treatments were applied with a tractor boom sprayer at 30 gpa, 40 psi, with 3 nozzles (1 directed at top of plant, 2 at sides) over each row. Insect counts were done weekly from 18 Jul to 28 Aug approximately 4 days after spraying. A prespray count was done 3 Jul. Four randomly chosen plants were sampled from the center row of each plot. Four cabbages per ploi were harvested on 30 Aug; each was weighed and rated for wrapper leaf and head damage. Analyses of variance were performed on weekly egg counts and larval counts, as well as seasonal totals of eggs and larvae. Harvest head weight and damage rating data were also analyzed. Student-Newman-Keuls multiple comparison analysis was performed on significantly different means.
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