Safening grain sorghum injury from metsulfuron with growth regulator herbicides

Abstract

Abstract Field and greenhouse experiments were conducted to evaluate the efficacy and safening of metsulfuron applied with dicamba, 2,4-D, clopyralid, and fluroxypyr with and without nonionic surfactant. Greenhouse data showed that 2,4-D and dicamba, but not fluroxypyr, safened grain sorghum from metsulfuron injury. In the field study, grain sorghum injury from metsulfuron was decreased when tank mixed with 2,4-D or dicamba but not when tank mixed with clopyralid or fluroxypyr. Tank mixes of 2,4-D or dicamba with metsulfuron did not reduce ivyleaf morningglory or velvetleaf control. At 4 wk after treatment (WAT), ivyleaf morningglory was controlled 95, 84, 59, and 91%, and velvetleaf was controlled 88, 82, 78, and 95% when metsulfuron was tank mixed with 2,4-D, dicamba, clopyralid, and fluroxypyr, respectively. In a separate field study, differential grain sorghum hybrid responses to a tank mix of metsulfuron + 2,4-D was examined. In general, a tank mix of metsulfuron and 2,4-D caused visible injury to al...