SETHOXYDIM AND CROP OIL CONCENTRATE INCREASE PYRIDATE PHYTOTOXICITY IN TRANSPLANTED CABBAGE (BRASSICA-OLERACEA)

Greenhouse and field studies were conducted in 1991 and 1992 to determ ine the potential for interaction among pyridate (0.5, 1.0 kg ai/ha), sethoxydim (0.22 kg ai/ha), and crop oil concentrate (COG) (1.25% v/v) applied alone or in two- and three-way combinations to transplanted c abbage. Additionally, the effect of applying sethoxydim and COC 1 and 2 d before and after application of pyridate was investigated. In gree nhouse-grown cabbage, injury increased twofold and dry weight was redu ced 15% when pyridate dose was doubled. Sethoxydim increased pyridate injury significantly, reducing dry weight 31%. When COC was applied wi th pyridate, injury increased and dry weight decreased linearly. Despi te substantial crop injury 7 d after treatment with pyridate alone, py ridate + sethoxydim, and pyridate + COG, yields of field-grown cabbage were reduced significantly in I yr only when the three materials were combined. Pyridate injury decreased as time between sethoxydim + COC applications, before and after pyridate was applied, increased.