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 and goosegrass control in common bermudagrass. Large crabgrass control was 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 applied at 1.7 kg ha−1followed 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 compared to diclofop alone. POST applications of diclofop, MSMA, and MSMA plus metribuzin did not injure common bermudagrass more severely when applied to plots previously treated with prodiamine and oryzalin than with POST herbicides alone.