Table 1. Experimental and agronomic information.
| | Langdon |
|---|
| Trial Latitude (LLC) | 48.75539 |
| Trial Longitude (LLC) | -98.34080 |
| Canola Variety | DK400TL |
| Previous Crop | HRSW |
| Planting Date | May 22 |
| Emergence Date | June 4 |
| Plot Size | 3.5 ft x 20 ft |
| Row Spacing | 6 inches |
| Seeding Depth | 0.75 inch |
| Seeding Rate | 14 seeds/ft2 |
| Experimental Design | RCBD, 4 reps |
| Harvest Date | September 25 |
Materials and Methods
The trial was conducted at the Langdon Research Extension Center in Langdon, ND. See Table 1 for planting dates, trial design, seeding rates and other information.
Seed treatment efficacy was examined for control of crucifer and striped flea beetles in spring canola. Treatments, rates and active ingredients are listed in Table 2. Dekalb DK400TL canola seed was treated prior to planting. Two neonicotinoid seed treatments, Helix Vibrance (thiamethoxam) and Prosper Evergol (clothianidin) were tested alone and in combination with either Lumiderm or Fortenza (cyantraniliprole). Prosper Evergol also was tested in combination with two rates of Buteo Start (flupyradifurone), and in combination with the commercial rates of Lumiderm and Buteo Start. Lastly, we included two treatments using a second hybrid, InVigor L350, treated commercially with Helix Vibrance and Lumiderm. InVigor L350 was included because we had second-hand reports of this hybrid having less severe feeding injury compared to other hybrids with the same seed treatment package.
Table 2. Treatments, active ingredients and rates used in the trial.
Treatment No. | Treatment Name | Product Rate(s) | Active Ingredient(s) | AI Rate (s) |
|---|
1 | Fungicide Check | | | |
2 | Helix Vibrance | 23 fl oz/cwt | Thiamethoxam | 400 g/100 kg |
3 | Helix Vibrance Fortenza1 | 23 fl oz/cwt 10.2 fl oz/cwt | Thiamethoxam Cyantraniliprole | 400 g/100 kg 400 g/100 kg |
4 | Prosper Evergol | 21.5 fl oz/cwt | Clothianidin | 400 g/100 kg |
5 | Prosper Evergol Lumiderm | 21.5 fl oz/cwt 9.8 fl oz/cwt | Clothianidin Cyantraniliprole | 400 g/100 kg 400 g/100 kg |
6 | Prosper Evergol Buteo Start2 | 21.5 fl oz/cwt 9.6 fl oz/cwt | Clothianidin Flupyradifurone | 400 g/100 kg 300 g/100 kg |
7 | Prosper Evergol Buteo Start | 21.5 fl oz/cwt 16 fl oz/cwt | Clothianidin Flupyradifurone | 400 g/100 kg 500 g/100 kg |
8 | Prosper Evergol Lumiderm Buteo Start2 | 21.5 fl oz/cwt 9.8 fl oz/cwt 9.6 fl oz/cwt | Clothianidin Cyantraniliprole Flupyradifurone | 400 g/100 kg 400 g/100 kg 300 g/100 kg |
9 | Hybrid L350 Helix Vibrance Lumiderm | 23 fl oz/cwt 9.8 fl oz/cwt | Thiamethoxam Cyantraniliprole | 400 g/100 kg 400 g/100 kg |
1Fortenza substituted for Lumiderm, rate(s) adjusted to match commercial Lumiderm rate and cyantraniliprole concentration.
2Commercial Buteo Start rate when used in combination with a neonicotinoid.
Sampling activities, dates and crop stages are given in Table 3. Plots were rated for flea beetle feeding injury using the 0-6 scale developed by Dr. Janet Knodel, with 0 = no feeding and 6 = dead plant. Within each plot, 10 randomly selected seedlings were rated. For analysis, the 10 ratings were averaged for a single rating value per plot. We attempted to rate feeding injury at 3, 7, 10 and 14 days after emergence (DAE), but this was not possible for the last rating due to weather. Plant stand was measured after the last injury ratings were made by counting the number of live plants in three square feet at two locations within each plot, and calculating the number of plants per square foot. Plots were harvested at maturity by straight combining with a research plot combine. Grain weight and percent moisture content were collected with the Harvest Master weigh system on the combine. Yields were adjusted to 10% standard grain moisture. All data were analyzed using the GLIMMIX procedure in SAS version 9.4 statistical software. The Tukey HSD post-hoc test (P<0.05) was used to test for significance among treatment means.
Table 3. Sampling activities, sampling dates, and crop stages.
Activity | Date | DAE | Crop Stage |
|---|
Injury Rating 1 | June 7 | 3 DAE | Cotyledon |
Injury Rating 2 | June 11 | 7 DAE | 2-leaf |
Injury Rating 3 | June 14 | 10 DAE | 3-leaf |
Injury Rating 4 | June 19 | 15 DAE | 4-leaf |
Stand Counts | June 19 | 15 DAE | 4-leaf |
Results and Discussion
Flea beetle activity and seedling feeding was unusually light due to cold, wet conditions from mid-May through June. These conditions favored canola growth but not flea beetle activity. Flea beetles are most active and destructive to canola seedlings when warm, dry conditions exist during the susceptible seedling stages from emergence through the 6-leaf stage. Consequently, seedling injury was relatively low regardless of the seed treatment package tested.
Treatment means are presented in Table 4. There were no significant differences among treatments for plant stand, yield, and feeding injury at 3, 7, and 10 DAE. Treatment 9, InVigor L350 with the commercial Helix Vibrance and Lumiderm seed treatment package, was not significantly different from Treatment 3 (DK400TL with the equivalent seed treatment package) for plant stand, yield, and feeding injury at 3, 7 and 10 DAE. However, Treatment 9 had significantly less feeding injury than all other treatments at 15 DAE. This may be due to better seedling vigor compared to DK400TL where InVigor L350 was able to grow through earlier feeding injury more quickly than DK400TL. While not statistically significant, Treatment 9 had the highest yield of all treatments, which seems to support a hybrid performance difference rather than a seed treatment efficacy difference. With the increased availability of many new straight-cut hybrids, hybrid performance using the most commonly available commercial seed treatments should be examined in more rigorous detail.
Table 4. Treatment means for seed treatments for flea beetle injury, plant stand, and grain yield at Langdon, 2024.
Trt. No. | Treatment | Injury 3 DAE | Injury 7 DAE | Injury 10 DAE | Injury 15 DAE | Plant Stand (plants/ft2) | Grain Yield (lbs/acre) |
|---|
1 | Fungicide Check | 2.4 | 3.7a | 3.8a | 2.7abc | 7.2a | 2,384.7a |
2 | Helix Vibrance @ 23 | 2.2 | 3.4a | 3.9a | 3.3a | 9.5a | 2,481.8a |
3 | Helix Vibrance @ 23 Fortenza @ 10.2 | 1.4 | 2.6a | 3.3a | 3.1ab | 8.8a | 2,566.0a |
4 | Prosper Evergol @ 21.5 | 1.7 | 2.9a | 3.7a | 2.9abc | 9.3a | 2,496.5a |
5 | Prosper Evergol @ 21.5 Lumiderm @ 9.8 | 1.1 | 2.3a | 3.5a | 2.9abc | 7.9a | 2,535.4a |
6 | Prosper Evergol @ 21.5 Buteo Start @ 9.6 | 1.0 | 2.9a | 3.7a | 2.8abc | 8.3a | 2,491.9a |
7 | Prosper Evergol @ 21.5 Buteo Start @ 16 | 1.3 | 2.9a | 3.4a | 2.4bc | 8.1a | 2,684.8a |
8 | Prosper Evergol @ 21.5 Lumiderm @ 9.8 Buteo Start @ 9.6 | 0.8 | 2.1a | 3.4a | 2.4c | 8.8a | 2,652.5a |
9 | Hybrid L350 Helix Vibrance @ 23 Lumiderm @ 9.8 | 1.6 | 3.0a | 3.2a | 1.6d | 7.8a | 3,002.1a |
| | F-value | 1.94 | 1.17 | 1.08 | 12.03 | 0.92 | 2.01 |
| | P-value | 0.10 | 0.35 | 0.41 | <0.0001 | 0.52 | 0.09 |
Means within a column that share the same letter are not significantly different (Tukey’s HSD at P<0.05).
Acknowledgements
We would like to thank the Northern Canola Growers Association and our field workers, Brock Freer, Kartheek Chapara, Carter Mosher, and Tucker Gellner. We also appreciate the untreated canola seed supplied by Jim Johnson of Star Specialty Seeds and treated seed by Jordan Varberg of BASF.
