RESULTS OF AGRONOMIC AND WEED SCIENCE RESEARCH CONDUCTED IN SOUTH CENTRAL MONTANA

Transcription

1 RESULTS OF AGRONOMIC AND WEED SCIENCE RESEARCH CONDUCTED IN SOUTH CENTRAL MONTANA The Annual Report of the Investigations at and Administration of the Southern Agricultural Research Center, Huntley, Montana PROJECT TITLE: PROJECT LEADER: OBJECTIVES: METHODS: Control of Wild Oats in Malt Barley with Silverado Osprey Steven R. King, Weed Scientist, SARC, Huntley, MT To determine the efficacy of Silverado & Osprey for wild oat control in Malt Barley Herbicides were applied POST with a CO 2 backpack sprayer calibrated to deliver 10 gal/a using 8001XR nozzles spaced 18 inches apart. Weed response following herbicide applications was evaluated visually using a rating scale that ranged from 0 (no visible injury) to 100% (complete plant death) Weed control ratings were determined visually estimating the amount of weed biomass present in each plot compared to the non-treated control plots. Plots were harvested with an experimental plot combine. Reported grain yields were adjusted to 13% grain moisture content, and based on a 48 pound per bushel test weight. Percent moisture and test weight were determined using a laboratory grain analyzer. Experimental site and herbicide application data are presented in Table 1 and Table 2. Table 1. Site information Field: A Soil Type: Clay loam Planting Date: 3/14/05 Variety: Moravian Planting population: 100 lb/a Row Spacing: 6 inches Date Harvested: 7/26/05 Table 2. Herbicide application Treatment Timing: POST Date Treated: 5/16/05 Time: 2:00 PM Soil Moisture (Surface): Moist Barley Stage: 3 tiller, 5 Weeds: Wild Oat (AVEFA) Stage: 2-5 tiller Density: 60 m 2

2 RESULTS: An experiment was conducted in 2005 in Huntley, Montana to evaluate mesosulfuron-methyl for the control of wild oat in. Mesosulfuron-methyl is the active ingredient in two herbicides produced by Bayer CropScience that are registered for use in wheat. These herbicides, Silverado and Osprey, contain mesosulfuron-methyl and the safener mefenpyr-diethyl at a ratio of 1:6 and 1:2, respectively. Silverado and Osprey were applied alone at two rates (low and high) or in combination with other small grain herbicides that are typically used for broadleaf weed control. These small grain herbicides included thifensulfuron plus tribenuron, clopyralid plus fluroxypyr, and bromoxynil plus MCPA. Silverado and Osprey treatments contained methylated seed oil and ammonium sulfate at 1.5 pints per acre and 3 pounds per acre, respectively. Herbicide treatments were arranged factorially in a randomized complete block design with four replications. These treatments were compared to standard treatments of tralkoxydim and fenoxyprop. At 3 and 8 weeks after treatment (WAT), the main effects of herbicide, rate, and the addition of other small grain herbicides were determined to be significant with respect to injury. Silverado applied alone at the low and high rates caused injury of 7 and 11% at 3 WAT and 4 and 7% at 8 WAT, respectively. Osprey applications resulted in 9 and 17% greater injury at 3 WAT compared to Silverado when these herbicides were applied alone at the low and high rate, respectively. At 8 WAT, injury from Osprey applications was 12 and 18% greater than injury from Silverado applied at the low and high rate, respectively. When Silverado was applied alone at the low or high rate injury was significantly greater when combined with bromoxynil plus MCPA at 3 and 8 WAT. Greater levels of injury were also observed when Osprey was combined with bromoxynil plus MCPA at 3 and 8 WAT. Wild oat was controlled between 89 and 93% at 3 WAT and 92 and 98% at 8 WAT with all Silverado and Osprey treatments regardless of rate or the addition of other small grain herbicides. Wild oat control with Silverado and Osprey were similar to that provided by tralkoxydim and fenoxyprop at 8 WAT. No difference is yield was observed between treatments, however, percent plump kernels was lower in plots receiving an application of Osprey in comparison to those that received an application of Silverado. No difference in the percentage of plump kernels occurred between treatments of Silverado, tralkoxydim or fenoxyprop. Results indicate that Silverado applied alone or in combination with thifensulfuron plus tribenuron or clopyralid plus fluroxypyr are effective treatments for the control of wild oat in and result in yield and quality similar to the labeled treatments of tralkoxydim and fenoxyprop.

3 TABLE 3: BARLEY INJURY AND WEED CONTROL RATINGS Pest Code AVEFA AVEFA AVEFA Pest Name wild oat wild oat wild oat Crop Name Crop Variety Description Part Rated injury injury contro injury contro injury contro Rating Date 5/24/2005 6/6/2005 6/6/2005 6/20/2005 6/20/2005 7/11/2005 7/11/2005 Rating Data Type visual visual visual visual visual visual visual Rating Unit Days After First/Last Applic Trt-Eval Interval 8 DA-A 21 DA-A 21 DA-A 35 DA-A 35 DA-A 56 DA-A 56 DA-A Trt Treatment Rate No. Name Rate Unit 1 Silverado 1.75 OZ/A 5 bcd 7 ef 85 c 7 def 90 a 4 hi 95 a 2 Silverado 1.75 OZ/A 6 bcd 10 ef 89 abc 7 def 91 a 8 ghi 93 a 3 Silverado 1.75 OZ/A 8 bc 10 ef 88 bc 7 def 91 a 4 hi 92 a 4 Silverado 1.75 OZ/A 7 bc 16 de 90 abc 13 cd 91 a 10 e-i 94 a 5 Silverado 2.25 OZ/A 8 bc 11 e 88 bc 9 c-f 93 a 7 ghi 98 a OZ/A 6 Silverado 2.25 OZ/A 8 bc 13 e 89 abc 10 c-f 97 a 9 f-i 98 a

4 7 Silverado 2.25 OZ/A 9 b 15 e 93 ab 12 cde 95 a 11 e-i 96 a 8 Silverado 2.25 OZ/A 12 ab 18 de 89 abc 13 cd 93 a 13 e-h 94 a 9 Osprey 2.5 OZ/A 10 b 16 de 86 bc 19 bc 89 a 16 efg 93 a 10 Osprey 2.5 OZ/A 11 b 18 de 90 abc 19 bc 88 a 18 def 94 a 11 Osprey 2.5 OZ/A 10 b 19 de 89 abc 19 bc 90 a 19 cde 93 a 12 Osprey 2.5 OZ/A 13 ab 38 ab 91 abc 36 a 88 a 35 ab 96 a 13 Osprey 3.2 OZ/A 12 ab 28 c 91 abc 26 b 88 a 25 cd 96 a 14 Osprey 3.2 OZ/A 12 ab 26 cd 93 ab 29 ab 95 a 28 bc 97 a

5 15 Osprey 3.2 OZ/A 13 ab 33 bc 91 abc 29 ab 91 a 28 bc 97 a 16 Osprey 3.2 OZ/A 18 a 43 a 93 ab 38 a 95 a 36 a 98 a 17 Achieve 6.9 OZ/A 0 d 0 f 91 abc 1 ef 94 a 1 i 96 a Supercharge 0.5 % V/V 18 Puma 10.6 OZ/A 2 cd 1 f 95 a 0 f 95 a 0 i 96 a 19 Control 0 d 0 f 0 d 0 f 0 b 0 i 0 b 20 control 0 d 0 f 0 d 0 f 0 b 0 i 0 b LSD (P=.05) Standard Deviation

6 Table 4. Barley Yield Data. Pest Code 22 X 4 22 X 4 22 X 4 Pest Name test wt moisture yield at 13% % plump % regular % thins Crop Name Crop Variety Description Part Rated yield c yield c yield c Rating Date 7/26/2005 7/26/2005 7/26/2005 Rating Data Type pounds percent bushels Rating Unit Days After First/Last Applic Trt-Eval Interval 71 DA-A 71 DA-A 71 DA-A Trt Treatment Rate No. Name Rate Unit 1 Silverado 1.75 OZ/A 51 ab 14 b 97 a 94 ab 4 ef 2 de 2 Silverado 1.75 OZ/A 51 ab 14 b 97 a 92 abc 5 def 3 cde 3 Silverado 1.75 OZ/A 51 abc 14 b 96 a 93 abc 5 def 2 cde 4 Silverado 1.75 OZ/A 50 b-e 14 b 100 a 90 a-d 7 c-f 3 cde 5 Silverado 2.25 OZ/A 51 ab 14 b 96 a 94 ab 4 f 2 cde OZ/A

7 6 Silverado 2.25 OZ/A 51 ab 14 b 92 a 92 abc 5 def 3 cde 7 Silverado 2.25 OZ/A 50 bcd 14 b 90 a 93 abc 5 def 2 cde 8 Silverado 2.25 OZ/A 50 bcd 14 b 101 a 89 a-d 8 b-e 3 cde 9 Osprey 2.5 OZ/A 50 cde 14 b 98 a 87 cde 9 bc 4 b-e 10 Osprey 2.5 OZ/A 49 ef 14 b 96 a 83 efg 11 ab 6 ab 11 Osprey 2.5 OZ/A 50 de 14 b 98 a 88 b-e 8 bcd 4 b-e 12 Osprey 2.5 OZ/A 48 f 15 a 99 a 80 g 13 a 7 a 13 Osprey 3.2 OZ/A 50 cde 14 b 98 a 86 def 9 abc 5 bc 14 Osprey 3.2 OZ/A 49 ef 14 b 99 a 84 d-g 10 abc 6 ab

8 15 Osprey 3.2 OZ/A 49 ef 14 b 86 a 86 def 10 abc 4 bcd 16 Osprey 3.2 OZ/A 48 f 15 a 94 a 81 fg 13 a 6 ab 17 Achieve 6.9 OZ/A 51 ab 14 b 106 a 95 a 3 f 2 de Supercharge 0.5 % V/V 18 Puma 10.6 OZ/A 51 a 14 b 102 a 95 a 3 f 1 e 19 Control 51 ab 14 b 90 a 94 ab 4 ef 2 de 20 control 51 ab 14 b 93 a 94 ab 4 ef 2 cde LSD (P=.05) Standard Deviation