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ARS Home » Research » Publications at this Location » Publication #128015
Title: ADJUVANTS AND CROP TOLERANCE ON SOYBEAN, URBANA, ILLINOIS, 2001

Author
item WAX, LOYD
item SPRAGUE, CHRISTY - UNIV OF ILLINOIS
item MAXWELL, DOUGLAS - UNIV OF ILLINOIS

Submitted to: Research Report North Central Weed Science Society United States
Publication Type: Other
Publication Acceptance Date: 12/12/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The objective was to evaluate adjuvant effects on crop tolerance in soybean. The study was established at the University of Illinois Crop Sciences Research and Education Center, Urbana. The soil was a Drummer Silty-clay loam with a pH of 6.4 and 5.3% organic matter. Asgrow 3302 soybean were planted 1.5 inches deep on May 15 in 30 inch rows. Treatments were arranged in randomized complete blocks with three replications of plots 10 by 20 feet. Herbicides were applied with a CO2 backpack sprayer delivering 20 gpa and equipped with 8003 flat fan nozzles. All COC = Herbimax. AMS = N-Pak 21% active, at % volume/volume. Blanket application of 1.6 lb/A S-metolachlor & CGA154281 and 0.031 lb/A cloransulam preemergence on May 15 combined with cultivation and hand weeding to maintain weed free plots. Soybean tolerance to postemergence herbicide treatments varied considerably with different adjuvants, as injury ranged from 7 to 42% when evaluated 4 days after treatment. A few of the differences between adjuvants with a given herbicide mixture were significant, but for the most part were not significantly different. By 10 DAT, injury symptoms were beginning to disappear in most treatments, and by 4 weeks after treatment, essentially all injury symptoms disappeared. In most instances, early injury did not appear to correlate to grain yields, as most treatment yields were similar to the hand weeded plots.