Ohio State University Research/Extension Bulletin

Agronomic Crops Team On-Farm Research Projects 1997

Special Circular 160-98


SOYBEAN

Roundup Ready Soybean Herbicide Trial

Objective

Evaluate various combinations of Roundup Ultra with pre-emergent herbicides and other post-emergence programs for the control of grass and broadleaf weeds in Roundup Ready soybeans.

Cooperator: Tom Weiler
County of Site: Morrow
Nearest Town: Chesterville
Major Soil Type: Millgrove
Drainage: Systematic
Irrigation: None
Tillage: Fall chisel and field cultivate twice
Previous Crop: Corn
Soil Test: pH 7.0
P 23 ppm
K 154 ppm
Fertilizer: None
Plant Population: 204,000/A
Plant Pop. @Harvest: 154,000/A
Variety: Stine 3264RR and Pioneer 9333RR
Planting Date: May 8
Harvest Date: October 9

Methods and Results

HerbicidesRate/Ac Growth
Stage
Control Rating (%) Costs ($/Ac)
Annual
Grass
Lambs-
quarters
Giant
Ragweed
Velvet-
leaf
Herbicides Application Total
Roundup Ultra1 qt.LPO9999919313.004.0017.00
Roundup Ultra1.5 pt.LPO999897969.754.0013.75
Roundup Ultra1.0 EPO 989896956.50 4.0021.00
1.0LPO6.504.00
Canopy 3.0 oz.PRE999996977.884.0022.38
Roundup Ultra 1.0 pt.LPO 6.50 4.00
Roundup Ultra0.5 pt.EPO999196853.254.0016.13
Roundup Ultra 0.75 pt.LPO 4.884.00
Canopy XL3.0 oz.PRE999998988.444.0022.94
Roundup Ultra1.0 pt.LPO 6.504.00
Dual II1.0 qtPRE9286999717.504.0027.07
Firstrate0.33 oz.LPO *4.00+?
COC 1.0 qtLPO1.18
28% N.2.5%v/vLPO 0.39
Dual II1.0 qt. PRE9978959317.504.0041.28
Flexstar2.5 pt.LPO15.004.00
MSO 1.0%v/vLPO0.78
Cobra 8.0 oz.LPO 897495908.384.0025.75
Select 8.0 oz.LPO12.19
CBC 1.0%v/vLPO 1.18
Control Rating - percent of weeds controlled
PRE - Pre-emergent application
EPO - Early post-emergence - weeds less than 3 inches
LPO - Late post-emergence - weeds generally in the 4- to 12-inch range * Price of Firstrate unknown
Application cost used was $4.00 per acre. Costs may and will vary among farms.

Summary and Notes

Using Roundup-Ready soybeans with Roundup Ultra is another weed control option for soybean producers. Roundup can be used post-emergent on varieties with the gene incorporated in it. Herbicide prices were in-season retail prices. The ratings are the average of four replications in the study. The plots were 40' x 10' in size. The Pioneer 9333 RR beans ran 53.8 bushels per acre and Stine 3264RR produced 58.1 bushels per acre. The weed plots had moderate weed pressure from all the weeds rated.

For additional information, contact:

Steve Ruhl
Ohio State University Extension - Morrow County
871 W. Marion Rd., Suite 102
Mt. Gilead, OH 43338
419-947-1070
ruhl.1@osu.edu


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