NDSU

CANOLA:  Brassica napus L., ‘RaideRR’

Insecticide Seed Treatment Efficacy Against Flea Beetles on Canola Trial A, 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, the Langdon REC in Langdon, and the Carrington REC in Carrington. Brassica napus cv. RaideRR (Integra Seed Ltd., open pollinated) was seeded on 20 May in Minot, 13 May in Langdon and 1 May in 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 19, 26, 34, and 41 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 at Minot and Carrington. However, Ronilan (12 oz/acre at 20-50% bloom) was sprayed in Langdon.  Plots were harvested on 12 Aug in Minot, 2 Sep in Langdon, and 18 Aug in Carrington. 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 at Minot, Carrington, and Langdon. However, Gaucho 600 had a higher damage rating than the other insecticide seed treatments and was similar to the untreated check. Helix xtra, Helix lite, Prosper 400, and Prosper 200 were usually not significantly different from each other at Minot and Carrington where flea beetle pressures were lighter. At Langdon where flea beetle pressures were the heaviest, Helix xtra, Helix lite, and Prosper 400 had a significantly lower damage rating than the untreated check. Only Helix xtra was also significantly lower than Prosper 200 and Gaucho 600. Helix xtra, Helix lite, and Prosper 400 were comparable in damage ratings. At Minot and Carrington, there were no significant differences in yield. At Langdon, all of the insecticide seed treatments had a significantly higher yield than the untreated check. Helix xtra was also significantly higher than Prosper 200 and Gaucho 600, but not Prosper 400 and Helix lite. Prosper 200 was similar to Prosper 400 and Helix lite. Overall, the high rate of insecticide seed treatments averaged 755 lb/acre more than the untreated check (808 lb/acre for Helix xtra and 701 lb/acre for Prosper 400); the low rate of insecticide seed treatments averaged 477 lb/acre more than the untreated check (487 lb/acre for Helix lite and 466 lb/acre for Prosper 200); and Gaucho 600 averaged 324 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. Carrington.

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 3. 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, 2003