Experiments were conducted in Georgia, North and South Carolina, and Mississippi to evaluate bromoxynil (Buctril) herbicide for postemergence (POST) control of broadleaf weeds in bromoxynil-resistant transgenic cotton. Single and sequential applications of Buctril POST at 1.5 lb ai/ac were evaluated with and without Cotoran applied preemergence (PRE). Standard postdirected sequential systems were also evaluated, as were several Buctril rate studies alone and with MSMA or with Cotoran, and antagonism studies with POST graminicides for annual and perennial grass control.

Buctril at 1.5 lb/ac as single or sequential applications without Cotoran PRE, provided >90% control of spurred anoda, prickly sida, coffee senna, common ragweed, and ivyleaf and entireleaf morningglories. Sequential applications were required for >90% control of spotted spurge. Cotoran PRE plus sequential applications of Buctril provided 69% sicklepod control. Buctril at 0.25 lb/ac controlled common lambsquarters, smallflower, entireleaf, pitted, and tall morningglories at least 93%. Redroot pigweed control of >90% took at least 1.0 lb/ac of Buctril.

Cotoran and MSMA tank mixed with Buctril did increase sicklepod control compared to Buctril, Cotoran, or MSMA applied alone. Buctril rates above 1.5 lb/ac provided better suppression and control of sicklepod than tank mixes with Cotoran or MSMA.

Evaluations of Buctril tank mixed or 24 h sequentials (Buctril first or graminicide applied first) with Fusilade 2000, Poast Plus, Assure II, and Select found appreciable antagonism for rhizome johnsongrass control. Texas panicum, large crabgrass, and dinitroaniline resistant goosegrass control was not antagonized with Buctril.