Response of four sweet corn hybrids to weed management level.

Authors: Boydston, Rick; Williams, Martin

Submitted to: Western Society of Weed Science Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2010
Publication Date: 3/7/2011
Citation: Boydston, R.A., Williams, M. 2011. Response of four sweet corn hybrids to weed management level.. Western Society of Weed Science Meeting Proceedings. (145). http://wssaabstracts.com/public/6/proceedings.html#pres145.

Interpretive Summary: Planting no-till into cover crop residues left on the soil surface offers benefits of suppressing weeds, reducing soil erosion, and eliminating trips through the field. Adequate suppression of cover crops to prevent competition with the main crop can be challenging, particularly in organic systems where synthetic herbicides are not allowed. Three cover crop kill methods utilizing a roller-crimper were evaluated in studies conducted in Prosser, WA and Urbana, IL in 2009 and 2010. Cereal rye was planted alone and in combination with common vetch or hairy vetch at Prosser and Urbana, respectively. Cover crops were rolled and crimped at rye anthesis or later either once, twice, or once plus an application of glyphosate (rye and rye/vetch mix) or carfentrazone (vetch). Rolling and crimping once killed cereal rye from 91 to 99% over both locations and years and was not significantly improved by rolling a second time in 3 of 4 site-years. Applying glyphosate after rolling and crimping completely killed rye. Common vetch was suppressed 40 to 51% and hairy vetch 25 to 39% with one pass of a roller-crimper and a second pass only slightly improved vetch kill. Carfentrazone applied after rolling and crimping did not improve control of common vetch at Prosser in either year. Final dry weight of weeds in snap beans was not affected by cover crop kill method. Cover crop residues reduced weed biomass at snap bean harvest 0 to 89% at Prosser and 32 to 91% at Urbana compared to no cover crop controls. Cereal rye or a rye plus vetch mix suppressed weeds more consistently and completely than vetch alone. No-till planting snap beans into rolled and crimped cover crop residues often resulted in lower stands, delayed flowering, and reduced snap bean yield.

Technical Abstract: Planting no-till into cover crop residues left on the soil surface offers benefits of suppressing weeds, reducing soil erosion, and eliminating trips through the field. Adequate suppression of cover crops to prevent competition with the main crop can be challenging, particularly in organic systems where synthetic herbicides are not allowed. Three cover crop kill methods utilizing a roller-crimper were evaluated in studies conducted in Prosser, WA and Urbana, IL in 2009 and 2010. Cereal rye was planted alone and in combination with common vetch or hairy vetch at Prosser and Urbana, respectively. Cover crops were rolled and crimped at rye anthesis or later either once, twice, or once plus an application of glyphosate (rye and rye/vetch mix) or carfentrazone (vetch). Rolling and crimping once killed cereal rye from 91 to 99% over both locations and years and was not significantly improved by rolling a second time in 3 of 4 site-years. Applying glyphosate after rolling and crimping completely killed rye. Common vetch was suppressed 40 to 51% and hairy vetch 25 to 39% with one pass of a roller-crimper and a second pass only slightly improved vetch kill. Carfentrazone applied after rolling and crimping did not improve control of common vetch at Prosser in either year. Final dry weight of weeds in snap beans was not affected by cover crop kill method. Cover crop residues reduced weed biomass at snap bean harvest 0 to 89% at Prosser and 32 to 91% at Urbana compared to no cover crop controls. Cereal rye or a rye plus vetch mix suppressed weeds more consistently and completely than vetch alone. No-till planting snap beans into rolled and crimped cover crop residues often resulted in lower stands, delayed flowering, and reduced snap bean yield.