Objective:
To evaluate herbicide combinations applied pre planted and/or post planted on weed control performance in spring wheat in environments and cropping systems representative of northwestern Montana
Personnel:
Clint Beiermann, Jessica Pavelka
Summary:
Spring wheat was planted on April 27th, 2022 and thirteen different herbicide combination were tested (Tables 1, 2).
At four weeks after application there was 90% or greater control of wild oat in treatments (2) Axial Bold, (6) Prowl followed by (fb) Axial Bold, (7) Zidua SC fb Axial Bold, (8) Anthem Flex fb Axial Bold, (9) Prowl H2O + Axial Bold, (10) Zidua SC + Axial Bold, and (11) Anthem Flex + Axial Bold. Lambsquarters control was 88% or higher in treatments (3) Prowl H2O, (4) Zidua SC, (6) Prowl followed by (fb) Axial Bold, (7) Zidua SC fb Axial Bold, (8) Anthem Flex fb Axial Bold, (9) Prowl H2O + Axial Bold, and (11) Anthem Flex + Axial Bold (Table 3).
Weed density was assessed four weeks after the final POST treatments were applied. High amounts of wild oat were present in treatments (1) non-treated, (3) Prowl H2O, (4) Zidua SC, and (5) Anthem Flex. Lambsquarters density was higher in treatments with poor control, including (1) non-treated, (2) Axial Bold, and (10) Zidua SC + Axial Bold (Table 5).
There was a significant effect of herbicide treatment on crop injury. Treatments (2) Axial Bold, (6) Prowl H2O fb Axial Bold, (7) Zidua SC fb Axial Bold, and (8) Anthem Flex + Axial Bold ranged from 16-21.3% crop injury; however, spring wheat recovered from these injuries, as each of these treatments resulted in high yield. The highest yielding treatment was (8) Anthem Flex fb Axial Bold at 98.6 bu/A, while the non-treated yielded the lowest at 52.5 bu/A (Table 3). We cannot conclude that Prowl, Zidua, or Anthem Flex provided improved wild oat control beyond using Axial Bold as a POST treatment. Prowl, Zidua, and Anthem Flex did improve lambsquarters control compared to non-treated.
Table 1. Management Information |
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Seeding date: | 4/27/2022 | Field Location: | R6 |
Julian date: | 117 | Harvest date: | 8/23/2022 |
Seeding rate: | Julian date: | 235 | |
Previous crop: | Alfalfa | Soil type: | Creston Silt Loam |
Herbicide: | Study Treatments | Tillage: | Conventional |
Insecticide: | NA | Soil residual nutrient (NO3-1, P, K lb/A): | 78.5-6-122-8s |
Fungicide: | NA | Nutrient fertilizer applied (N, P2O5, K20 lb/A): | 80-50-60-10s |
Table 2. Spring Wheat Pre & Post Combinations |
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Trt No. | Trt Name | Form Concentration | Form Unit | Rate | Rate Unit | Appl Timing |
1 | Non-trt | |||||
2 | Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | POST |
3 | Prowl H2O | 3.8 | LBA/GAL | 2.0 | pt/a | Early POST |
4 | Zidua SC | 4.2 | LBA/GAL | 2.5 | fl oz/a | PRE |
5 | Anthem Flex | 4.0 | LBA/GAL | 3.0 | fl oz/a | PRE |
6 | Prowl H2O | 3.8 | LBA/GAL | 2.0 | pt/a | Early POST |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | POST | |
7 | Zidua SC | 4.2 | LBA/GAL | 2.5 | fl oz/a | PRE |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | POST | |
8 | Anthem Flex | 4.0 | LBA/GAL | 3.0 | fl oz/a | PRE |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | POST | |
9 | Prowl H2O | 3.8 | LBA/GAL | 2.0 | pt/a | Early POST |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | Early POST | |
10 | Zidua SC | 4.2 | LBA/GAL | 2.5 | fl oz/a | Early POST |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | Early POST | |
11 | Anthem Flex | 4.0 | LBA/GAL | 3.0 | fl oz/a | Early POST |
Axial Bold | 0.7 | LBA/GAL | 15.0 | fl oz/a | Early POST |
Table 3. Crop Injury & Yield |
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Treatment | Injury (%) | Yield |
1 WAT | (bu/A) | |
1 | - | 52.5 |
2 | 16.3 | 91.6 |
3 | 5.0 | 81.4 |
4 | 7.5 | 81.6 |
5 | 6.3 | 84.6 |
6 | 21.3 | 96.8 |
7 | 21.0 | 90.9 |
8 | 16.0 | 98.6 |
9 | 9.0 | 91.3 |
10 | 7.3 | 92.8 |
11 | 6.0 | 98.0 |
Mean | 11.6 | 87.3 |
CV | 38.4 | 8.4 |
LSD | 6.4 | 10.6 |
PR>F | <0.001 | <0.001 |
WAT = weeks after treatment
Table 4. Weed Control (4 WAT) |
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Treatment | Wild Oat | Lambsquarters |
% | % | |
2 | 99.0 | 10.0 |
3 | 16.3 | 99.0 |
4 | 18.8 | 89.5 |
5 | 22.5 | 68.5 |
6 | 99.0 | 99.0 |
7 | 99.0 | 89.5 |
8 | 99.0 | 88.3 |
9 | 99.0 | 99.0 |
10 | 96.8 | 32.5 |
11 | 99.0 | 99.0 |
Mean | 74.8 | 77.4 |
CV | 6.9 | 17.9 |
LSD | 7.5 | 20.2 |
PR>F | <0.001 | <0.001 |
WAT = weeks after treatment
Table 5. Weed Density (4 WAT) |
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Treatment | Wild Oat | Lambsquarters |
plants/m2 | plants/m2 | |
1 | 18.5 | 19.0 |
2 | 0.0 | 20.0 |
3 | 18.5 | 0.0 |
4 | 11.5 | 4.0 |
5 | 17.0 | 3.5 |
6 | 0.5 | 0.0 |
7 | 0.5 | 5.0 |
8 | 0.0 | 1.5 |
9 | 0.0 | 0.5 |
10 | 0.0 | 10.0 |
11 | 0.0 | 2.0 |
Mean | 6.0 | 6.0 |
CV | 72.2 | 92.9 |
LSD | 6.3 | 8.0 |
PR>F | <0.001 | <0.001 |
WAT = weeks after treatment