NDSU

CANOLA:  Brassica napus L., ‘RaideRR’

Insecticide Seed Treatment Efficacy Against Flea Beetles on Canola Trial B, 2003

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 and the Langdon REC in Langdon. Brassica napus cv. RaideRR (Integra Seed Ltd., open pollinated) was seeded on 20 May in Minot and 13 May in Langdon. The seeding rate was approximately 14-17 pure live seeds per sq. foot.  A RCB experimental design with four replicates was used. Experimental plots were 3.5-4.1 ft. (7 rows) x 20-22 ft. To evaluate flea beetle damage, assessments were taken at approximately 16, 23, 32, and 39 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. Roundup (1 pt./acre) + AMS was applied for weed control early in the season. A Ronilan fungicide application was not necessary in 2003 for disease control due to the unfavorable environmental conditions in Minot. However, Ronilan (12 oz/acre at 20-50% bloom) was sprayed in Langdon.  Plots were harvested on 12 Aug in Minot and 2 Sept in Langdon. Variables were subjected to ANOVA and means compared using Fisher’s PLSD at the 5% significance level.

Insecticide seed treatments usually had a significantly lower damage rating than the untreated check, and there were no significant differences between any of the insecticide seed treatments at Minot. Flea beetle pressures were heavier at Langdon. Prosper 400 and Helix xtra had significantly lower damage ratings than the untreated check on 24 and 41 DAP. The damage rating for Helix xtra, 3.3, was also significantly lower than Prosper 400, 4.4, on 39 DAP. For yield at Minot, only Helix xtra had a significantly higher yield than the untreated check, but it was not significantly different from Prosper 400 and Helix lite. At Langdon, all of the insecticide seed treatments had a significantly higher yield than the untreated check. Within the insecticide treatments, Helix xtra and Prosper 400 also had a significantly higher yield than Helix lite, Experimental A, and Prosper 200, but were not significantly different from each other. Helix lite, Experimental A, and Prosper 200 were also not significantly different from each other. Overall, the high rate of insecticide seed treatment averaged 1037 lb/acre more than the untreated check (1253 lb/acre more for Helix xtra and 832 lb/acre more for Prosper 400); the low rate of insecticide seed treatments averaged 428 lb/acre more than the untreated check (701 lb/acre more for Helix lite and 254 lb/acre more for Prosper 200); and Experimental A averaged 426 lb/acre more than the untreated check.

Table 1.  Minot.

Means within a column followed by the same letter are not significantly different (ANOVA, Fisher’s PLSD, P<0.05).
^aDAP = Days After Planting
^bDamage Rating: 1= 0-3 pits per seedling, 2= 4-9 pits per seedlings; 3= 10-15 pits per seedling; 4= 16-25 pits per seedling; 5= >25 pits per seedling; and 6= dead seedling.

Table 2. Langdon

Means within a column followed by the same letter are not significantly different (ANOVA, Fisher’s PLSD, P<0.05).
^aDAP = Days After Planting
^bDamage Rating: 1= 0-3 pits per seedling, 2= 4-9 pits per seedlings; 3= 10-15 pits per seedling; 4= 16-25 pits per seedling; 5= >25 pits per seedling; and 6= dead seedling.

Part II. Materials Tested for Arthropod Management

Insecticide Seed Treatment Efficacy Against Flea Beetles on Canola Trial B, 2003