Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-22T19:27:00.947Z Has data issue: false hasContentIssue false

Weed Control in Soybeans by Glyphosate Applied in the Recirculating Sprayer

Published online by Cambridge University Press:  12 June 2017

C.G. McWhorter*
Affiliation:
South. Weed Sci. Lab., Agric. Res. Serv., U.S. Dep. Agric., Stoneville, MS 38776

Abstract

Field experiments were conducted to study the feasibility of applying glyphosate [N-(phosphonomethyl)glycine] postemergence for the control of johnsongrass [Sorghum halepense (L.) Pers.], redroot pigweed (Amaranthus retroflexus L.), and hemp sesbania [Sesbania exaltata (Raf.) Cory] in soybeans [Glycine max (L.) Merr.]. Herbicide sprays were directed across the row to weeds growing taller than soybeans in June, July, and August. Herbicide not sprayed on weeds was trapped and reused. Glyphosate at 1.12 and 1.68 kg/ha effectively controlled johnsongrass with little soybean injury and with greatly increased soybean yields. The use of 0.1% surfactant frequently increased the toxicity of glyphosate at 1.12 and 1.68 kg/ha to soybeans, but this adverse effect was overcome by the use of 0.1% anti-drift polymer in sprays. Control of redroot pigweed with glyphosate at 1.12 kg/ha was improved by the use of 0.1% surfactant, but surfactant did not increase control with glyphosate at 1.68 kg/ha. Glyphosate at 1.68 kg/ha, with 0.1% surfactant, was required to provide more than 80% control of hemp sesbania. Glyphosate applied at 1.12 kg/ha in the recirculating sprayer provided equal johnsongrass control, increased soybean yields and caused less soybean injury than when glyphosate at 0.56 kg/ha was applied over-the-top in water or in foam.

Type
Research Article
Copyright
Copyright © 1977 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Connell, J.T. and Derting, C.W. 1973. Glyphosate performance on johnsongrass and associated weed species in no-tillage soybeans. Proc. South. Weed. Sci. Soc. 26:5158.Google Scholar
2. Crawford, S.H. and Rogers, R.L. 1973. Rhizome johnsongrass control in soybeans with glyphosate. Proc. South. Weed. Sci. Soc. 26:60.Google Scholar
3. Derting, C.W., Andrews, O.N. Jr., Duncan, R.G., and Frost, K.R. Jr. 1973. Two years of perennial weed control investigations with glyphosate. Proc. South. Weed Sci. Soc. 26:4450.Google Scholar
4. Klosterboer, A.D. 1973. Weed control in Texas citrus with glyphosate. Proc. South. Weed Sci. Soc. 26:276.Google Scholar
5. McWhorter, C.G. 1970. A recirculating spray system for postemergence weed control in row crops. Weed Sci. 18:285287.Google Scholar
6. McWhorter, C.G. 1972. Toxicity of Mon 0468 to johnsongrass and soybeans. Proc. South. Weed Sci. Soc. 25:117.Google Scholar
7. Mullins, J.A., Overton, J.R., and Jeffery, L.S. 1974. Response of soybeans and johnsongrass to glyphosate applications. Tenn. Farm and Home Sci. Prog. Rep. 90:1013.Google Scholar
8. Overton, J.R., Mullins, J.A., and Jeffery, L.S. 1973. Response of cotton, soybeans and johnsongrass to glyphosate. Proc. South. Weed Sci. Soc. 26:2835.Google Scholar
9. Overton, J.R., Mullins, J.A., and Jeffery, L.S. 1974. Combination of practices to control johnsongrass in soybeans. Tenn. Farm and Home Sci. Prog. Rep. 90:24.Google Scholar
10. Worsham, A.D. 1972. Mon 0468, a potential chemical control for perennial grass weeds in no-tillage crops. Proc. South. Weed Sci. Soc. 25:175184.Google Scholar