Objective:

To evaluate the efficacy of Dual II containing products for weed control in peas. 

Materials and Methods:

Seven herbicide treatments were evaluated for weed control and crop safety in peas. The experimental design was a randomized complete block with three replications. The herbicide treatments were applied preplant and then double incorporated with a field cultivator on April 12. Hi-line peas were planted on six inch row spacings, to a depth of three inches on April 21, at a rate of 220 lb/A. Foxtail, canola, wild buckwheat and common lambsquarters were seeded in the center of each plot on April 21.

Results:

No crop injury was observed. The most complete weed control was observed with Pursuit plus Prowl. The other treatments failed to provide adequate control of volunteer canola, which was the main weed present. Yield differences were significant at the 10% level of significance.

Summary:

Overall, the products containing Dual II did not perform as well as Pursuit plus Prowl H2O. 

Table 1. Materials and Methods.

Seeding Date: 4/21/2016 Harvest Date: 8/17/2016
Julian Date: 112 Julian Date: 230
Seeding Rate: 220 lb/A Soil Type: Creston SiL
Previous Crop: Barley Soil Test: 116-22-250-46
Tillage: Conventional Fertilizer: BC: 6-30-30

Table 2. Effect of Herbicides on Weed Control in Peas, Kalispell, MT - 2016.

Treatment Rate WC %
BRARA 		WC %
AMARE 		WC %
THLAR 		WC %
CHEAL 		YLD
bu/ac1		 TWT
lb/bu1
Check   0.0 0.0 0.0 0.0 33.9 64.1
Broadaxe XC 19 fl oz/a 23.3 95.0 94.3 96.0 61.1 64.5
Broadaxe XC +
Dual II 		10 fl oz/a +
8 fl oz/a 		0.0 95.0 93.3 95.0 42.9 65.4
Broadaxe XC 26 fl oz/a 16.7 93.3 95.0 95.0 52.4 64.7
Broadaxe XC +
Dual II 		10 fl oz/a +
13 fl oz/a 		0.0 95.0 93.3 95.0 53.9 64.8
Dual II 16 fl oz/a 0.0 95.0 88.3 95.0 37.6 64.5
Dual II 30 fl oz/a 0.0 85.0 86.7 95.0 37.0 64.7
Pursuit +
Prowl H20 		3 fl oz/a
2 pt/a 		75.0 96.0 96.0 96.0 87.7 63.5
Mean 14.4 81.8 80.9 83.4 50.8 64.5
CV 107.2 6.0 4.2 1.0 37.2 0.9
LSD 27.0 8.6 6.0 1.4 33.1 1.0
Pr>F 0.0004 0.0001 0.0001 0.0001 0.0584 0.0484

WC: weed control; BRARA: canola; AMARE: redroot pigweed; THLAR: field pennycress; CHEAL: common lambsquarters; YLD: yield; TWT: test weight

1 adjusted to 13% moisture