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Weed Management with Reduced Rates of Glyphosate in No-Till, Narrow-Row, Glyphosate-Resistant Soybean (Glycine max)

Published online by Cambridge University Press:  12 June 2017

Jimmy D. Wait
Affiliation:
Department of Agronomy, University of Missouri, Columbia, MO 65211
William G. Johnson*
Affiliation:
Department of Agronomy, University of Missouri, Columbia, MO 65211
Raymond E. Massey
Affiliation:
Department of Agricultural Economics, University of Missouri, Columbia, MO 65211
*
Corresponding author's E-mail: johnsonwg@missouri.edu.

Abstract

Field studies were conducted at two locations in 1997 and 1998 to evaluate crop injury, weed control, yield, and net economic returns of single and sequential postemergence applications of labeled and reduced rates of glyphosate to no-till, glyphosate-resistant soybean planted in narrow rows. Sequential applications provided at least 91% control of giant foxtail, while single applications provided at least 86% control with labeled rates and 68–93% control with reduced rates. Common waterhemp control was slightly higher with sequential vs. single treatments and with labeled rates vs. reduced rates. Velvetleaf control was greater than 96% with all treatments. Common cocklebur control was 90% or higher with all treatments except a single application of glyphosate at 210 g/ha. Lower control of giant foxtail and common waterhemp with single-application, reduced-rate treatments in two of the four trials resulted in lower yields. Overall, sequential applications, regardless of rate, provided greater weed control, yield, and net income and lower coefficients of variation (C.V.s) of net income than reduced-rate single applications. Single-application treatments showed a trend of decreased weed control, yield, and net income and higher C.V.s of net income with reduced rates of glyphosate.

Type
Research
Copyright
Copyright © 1999 by the Weed Science Society of America 

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Footnotes

1

Contribution from the Missouri Agricultural Experiment Station Journal Series.

References

Literature Cited

Buhler, D. D. and Burnside, O. C. 1983. Effects of spray components on glyphosate toxicity to annual grasses. Weed Sci. 31:124130.Google Scholar
Burnside, O. C. 1979. Soybean (Glycine max) growth as affected by weed removal, cultivar, and row spacing. Weed Sci. 27:562565.Google Scholar
Burnside, O. C. and Colville, W. L. 1964. Soybean and weed yields as affected by irrigation, row spacing and amiben. Weeds 12:109111.Google Scholar
Carey, J. B. and DeFelice, M. S. 1991. Timing of chlorimuron and imazaquin application in no-till soybeans (Glycine max). Weed Sci. 39:232237.CrossRefGoogle Scholar
[CTIC] Conservation Technology Information Center. 1996. West Lafayette, IN.Google Scholar
DeFelice, M. S., Brown, W. B., Aldrich, R. J., Sims, B. D., Judy, D. T., and Guethle, D. R. 1989. Weed control in soybeans (Glycine max) with below-label rates of postemergence herbicides. Weed Sci. 37:365374.Google Scholar
Devlin, D. L., Long, J. H., and Maddox, L. D. 1991. Using reduced rates of postemergence herbicides in soybeans (Glycine max). Weed Technol. 5:834840.Google Scholar
Johnson, W. G., Dilbeck, J. D., DeFelice, M. S., and Kendig, J. A. 1998. Weed control with reduced rates of imazaquin and imazethapyr in no-till narrow-row soybean (Glycine max). Weed Sci. 46:105110.Google Scholar
Johnson, W. G., Frans, R. E., and Parsch, L. D. 1991. Economics of johnsongrass (Sorghum halepense) control in soybean (Glycine max). Weed Technol. 5:765770.Google Scholar
Johnson, W. G., Kendig, J. A., Massey, R. E., DeFelice, M. S., and Becker, C. D. 1997. Weed control and economic returns with postemergence herbicides in no-till narrow-row soybean (Glycine max). Weed Technol. 11:453459.Google Scholar
Jordan, D. L., York, A. C., Griffin, J. L., Clay, P. A., Vidrine, P. R., and Reynolds, D. B. 1997. Influence of application variables on efficacy of glyphosate. Weed Technol. 11:354362.Google Scholar
Krausz, R. F., Kapusta, G., and Matthews, J. L. 1996. Annual weed control with glyphosate. Weed Technol. 10:957962.Google Scholar
Prostko, E. P. and Meade, J. A. 1993. Reduced rates of postemergence herbicides in conventional soybeans (Glycine max). Weed Technol. 7:365369.CrossRefGoogle Scholar
[USDA] U.S. Department of Agriculture. 1997. Missouri Farm Facts. Washington, D.C.: Department of Agriculture, Statistical Reporting Service. 86 p.Google Scholar
Wax, L. M., Nave, W. R., and Cooper, R. L. 1977. Weed control in narrow and wide row soybeans. Weed Sci. 25:7377.Google Scholar