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Insecticide Seed Treatment Efficacy against flea Beetles on Canola Trial A, 2004
Janet J. Knodel, Area Extension Specialist–Crop ProtectionLorilie Atkinson, Research Specialist North Central Research and Extension Center Bryan Hanson, AgronomistLangdon Research and Extension Center
Bob Henson, Agronomist Carrington Research and Extension Center
Crucifer flea beetle: Phyllotreta curiciferae Goeze
Striped flea beetle:
Phyllotreta
striolata F. Trials assessing the different insecticide seed treatments were conducted in research plots located at the North Central Research Extension Center (REC) in Minot, the Langdon REC in Langdon, and the Carrington REC in Carrington. Brassica napus cv. RaideRR (Integra Seed Ltd., open pollinated) was seeded on 7 May in Langdon and 17 May in Minot and Carrington. The seeding rate was approximately 14-17 pure live seeds per sq. foot. A RCB experimental design with four replicates was used. To evaluate flea beetle damage, assessments were taken at approximately 18, 27, and 34 Days After Planting (DAP) using the following rating scheme: 1 = 0-3 pits per seedling; 2 = 4-9 pits per seedling; 3 = 10-15 pits per seedling; 4= 16-25 pits per seedling; 5 = >25 pits per seedling; and 6 = dead. Percent coverage (% of land area in plot that was covered with canola seedlings) was estimated on 34 DAP. Roundup (1 pt./acre) + AMS was applied for weed control early in the season. Plots were harvested on 12 Aug in Minot, 9 Sep in Carrington, and 17 Sep in Langdon. Variables were subjected to ANOVA and means compared using Fisher’s PLSD at the 5% significance level.
There were no significant differences in flea beetle damage ratings on 19 DAP, regardless of the location. Flea beetles had not moved into plots to feed yet, due to the cool spring temperatures delaying emergence. All of the insecticide seed treatments had a lower damage rating than the untreated checks (fungicide seed treatment). In addition, the two high rates of insecticide seed treatments, Helix xtra and Prosper 400, usually had a lower damage rating than the two low rates of insecticide seed treatments, Helix lite and Prosper 200. For percent coverage, insecticide seed treatments had significantly higher percent coverage than the two untreated checks, but insecticide treatments were usually not significantly different from each other. At Langdon and Carrington, there were no significant differences in yield. At Minot, all of the insecticide seed treatments had a higher yield than the untreated check. However, only Helix xtra had significantly higher yield than untreated checks. Overall, the high rate of insecticide seed treatments averaged 445 lb/acre more than the untreated checks (428 lb/acre for Helix xtra and 461 lb/acre for Prosper 400); and the low rate of insecticide seed treatments averaged 294 lb/acre more than the untreated checks (277 lb/acre for Helix lite and 311 lb/acre for Prosper 200). Table 1. Minot.
Means within a column followed by the same letter are not significantly different (ANOVA, Fisher’s PLSD, P<0.05). a
DAP = Days After Planting Table 2. Carrington.
Means
within a column followed by the same letter are not significantly different
(ANOVA, Fisher’s PLSD, P<0.05). Table 3. Langdon.
Means
within a column followed by the same letter are not significantly different
(ANOVA, Fisher’s PLSD, P<0.05).
Insecticide Seed Treatment Efficacy against flea Beetles on Canola Trial A, 2004
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Last Updated:
Tuesday, July 05, 2005 10:26:36 AM
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