Tank-mix Combinations for Weed Control in Stale Seedbed Soybean ( Glycine max )

Glyphosate is often mixed with residual herbicides to control emerged weeds in no-till crop production systems. Field studies were conducted in Ohio from 1992 to 1994 to evaluate the weed control provided by residual herbicides and reduced rates of glyphosate in full-season, no-till soybean. Herbicide treatments were applied at two timings to examine the effect of weed size. At 4 wk after treatment, greater than 85% Pennsylvania smartweed control was obtained with metribuzin plus chlorimuron and linuron plus chlorimuron applied with 280 g ai/ha glyphosate and with imazethapyr and imazaquin applied with 560 g/ha glyphosate. All residual herbicides provided at least 85% common lambsquarters control when applied with 560 g/ha glyphosate. In 1992, the early application of residual herbicides provided this level of common lambsquarters control without glyphosate due to the small weed size at the time of application. Residual herbicides applied with 280 g/ha glyphosate controlled giant foxtail 85% or greater. Higher glyphosate rates were needed to control barnyardgrass. The performance of reduced glyphosate rates was dependent on weed species and weed size.

Section: Introductionsupporting

confidence: 90%

Section: Common Lambsquarters Control At 4 Wat Onlymentioning

confidence: 99%

Interactions of Glyphosate with Residual Herbicides in No-Till Soybean (Glycine max) Production¹

VanLieshout¹,

Loux²

2000

“…Glyphosate has been used for many years to control a broad spectrum of annual, biennial, and perennial species before crop emergence. A common management approach in conserva-tion tillage systems has been to tank-mix nonselective, foliarly applied herbicides with selective, soil-applied herbicides prior to or at planting (Bruff and Shaw 1992;Stougaard et al 1984). This has been an effective way to control existing vegetation and provide residual control (Buhler and Werling 1989;Wilson and Worsham 1988).…”

Section: Introductionmentioning

confidence: 99%

Weed Control from Herbicide Combinations with Glyphosate¹

Shaw¹,

Arnold²

2002

Self Cite

Greenhouse studies were initiated to evaluate glyphosate alone and tank-mixed with acifluorfen, CGA 277476, chlorimuron, cloransulam-methyl, fomesafen, imazaquin, or pyrithiobac on seedling johnsongrass, broadleaf signalgrass, pitted morningglory, and hemp sesbania. Johnsongrass and broadleaf signalgrass control by glyphosate was not affected by the selective herbicides applied in mixtures. Pitted morningglory control by glyphosate ranged from 0% with 280 g ai/ha to 67% with 840 g/ha. There was an additive effect when selective herbicides were added to 280 g/ha glyphosate 2 wk after treatment (WAT). When acifluorfen was added to 560 g/ha glyphosate, pitted morningglory control 2 WAT increased to 100% compared with 55% with glyphosate alone. Similarly, the addition of fomesafen or acifluorfen to 840 g/ha glyphosate controlled pitted morningglory 2 WAT by 90 and 98%, respectively, compared with 67% with glyphosate alone. Only tank mixtures of acifluorfen, CGA 277476, or fomesafen, and 840 g/ha glyphosate reduced fresh weight compared with glyphosate alone 4 WAT. Acifluorfen, CGA 277476, and fomesafen controlled pitted morningglory by 85 to 100% when added to 1,120 g/ha glyphosate. Both acifluorfen and fomesafen effectively controlled hemp sesbania without the addition of glyphosate 2 WAT. Chlorimuron and pyrithiobac added to 1,120 g/ha glyphosate increased hemp sesbania control to 88 and 99%, respectively, compared with 45% with glyphosate alone 2 WAT. CGA 277476, cloransulam-methyl, imazaquin, and pyrithiobac were antagonistic to hemp sesbania fresh weight reduction when compared with the expected response, but fresh weights were still reduced more than with the same rate of glyphosate alone.

“…Applying two or more herbicides sequentially or in mixture is commonly used to improve the spectrum of weed control, reduce production costs, and preclude the development of weeds resistant to certain herbicides (Bruff and Shaw 1992;Hydrick and Shaw 1994;Zhang et al 1995). However, it has been demonstrated that herbicides applied in mixture or sequentially may interact and result in synergistic, antagonistic, or additive response (Colby 1967).…”

Section: Introductionmentioning

confidence: 99%

Glufosinate Tank-Mix Combinations in Glufosinate-Resistant Rice (Oryza sativa)¹

Lanclos¹,

Webster²,

Zhang³

2002

At 14 d after treatment (DAT), glufosinate at 0.42 kg ai/ha controlled barnyardgrass and broadleaf signalgrass 85 and 86%, respectively. Antagonism occurred for barnyardgrass control with all mixtures of glufosinate at 0.42 kg/ha. At 14 DAT, no herbicide was superior to glufosinate at either rate when applied in mixture for the control of broadleaf signalgrass. Rice flatsedge control 7 DAT was 68 and 82% with glufosinate at 0.42 and 0.84 kg/ha alone, respectively. The addition of propanil and triclopyr enhanced rice flatsedge control over that with glufosinate alone at 0.42 or 0.84 kg/ha. At 7 DAT, all herbicide mixtures increased spreading dayflower control compared with a single treatment of glufosinate at 0.42 kg/ha. By 28 DAT, spreading dayflower control was less than 80% with all treatments. Rice injury was less than 15% with all treatments.