REDUCED RATES OF PREEMERGENCE AND POSTEMERGENCE HERBICIDES FOR LARGE CRABGRASS (DIGITARIA-SANGUINALIS) AND GOOSEGRASS (ELEUSINE-INDICA) CONTROL IN BERMUDAGRASS (CYNODON-DACTYLON)

Sequential applications of preemergence (PRE) and postemergence (POST) herbicides were applied over a two-year period for large crabgrass an d goosegrass control in common bermudagrass. Large crabgrass control w as better when prodiamine at 0.3 kg ai ha(-1) or oryzalin at 0.8 kg ai ha(-1) were applied in late February, and followed by MSMA at 1.1 kg ai ha(-1) in June than when prodiamine (0.8 kg ha(-1)) or oryzalin (2. 4 kg ha(-1)) were applied at recommended rates. Goosegrass control was better when prodiamine was applied at 0.3 kg ha(-1) followed by MSMA plus metribuzin at 2.2 + 0.1 kg ai ha(-1), or when oryzalin was applie d at 1.7 kg ha(-1) followed by MSMA plus metribuzin at 1.1 + 0.1 kg ha (-1) than when prodiamine was applied at 0.8 kg ha(-1) or oryzalin was applied at 3.3 kg ha(-1). There was no increase in goosegrass control when diclofop was applied in sequence after prodiamine or oryzalin co mpared to diclofop alone. POST applications of diclofop, MSMA, and MSM A plus metribuzin did not injure common bermudagrass more severely whe n applied to plots previously treated with prodiamine and oryzalin tha n with POST herbicides alone.