Insecticide Seed Treatment Efficacy against Flea Beetles on Canola Trial B, 2004

Janet Knodel, Area Extension Specialist, Crop Protection

Lorilie Atkinson, Research Specialist

North Central Research Extension Center

Bryan Hanson, Agronomist

Langdon 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 and the Langdon REC in Langdon. Brassica napus cv. RaideRR (Integra Seed Ltd., open pollinated) was seeded on 7 May in Landgon and 17 May in Minot. 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 19, 29, and 35 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 35 DAP. Roundup (1 pt./acre) + AMS was applied for weed control early in the season. Plots were harvested on 20 Aug in Minot 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. Insecticide seed treatments had a significantly lower damage rating than the untreated check, and there were no significant differences between any of the insecticide seed treatments for 29 and 35 DAP ratings at Minot, and 35 DAP rating at Langdon. Flea beetle pressures were heavier at Langdon than Minot. At 29 DAP, Helix xtra had a significantly lower damage rating than the other insecticides treatments and the untreated check. However, the other insecticides seed treatments also had a significantly lower damage rating than the untreated check. There were no significant differences in yield at Minot. At Langdon, all of the insecticide seed treatments had a significantly higher yield than the untreated check. Overall, the insecticide seed treatment averaged 293 lb/acre more than the untreated check:  299 lb/acre more for Helix xtra, 252 lb/acre more for Prosper 400, 358 lb/acre more for Experimental A and 259 lb/acre more for Experimental B. 

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
^b Damage 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).

^a DAP = Days After Planting
^b Damage 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, 2004

Last Updated: Tuesday, July 05, 2005 10:26:36 AM
Published by North Dakota State University