CHEMICAL CONTROL-SYSTEMS FOR COFFEE SENNA (CASSIA-OCCIDENTALIS) IN COTTON (GOSSYPIUM-HIRSUTUM)

Field experiments were established to evaluate coffee senna control in cotton with registered PRE, early POST-directed (EPD), and lace POST- directed (LPD) herbicides and with pyrithiobac applied PRE and early P OST. Fluometuron and norflurazon applied PRE controlled coffee senna 8 7 and 65%, respectively, 6 wk after planting (WAP). Methazole applied EPD controlled coffee senna 96% 2 wk after application, whereas fluome turon and MSMA applied EPD controlled 70 and 16%, respectively, LPD ap plications of cyanazine, diuron, and prometryn averaged only 45% contr ol 8 WAP. MSMA applied LPD controlled coffee senna only 12%, Fluometur on and norflurazon applied PRE followed by methazole applied EPD and c yanazine applied LPD controlled coffee senna 98 and 99% 6 WAP, respect ively, PRE, early POST, and PRE followed by early POST applications of pyrithiobac controlled coffee senna 88, 89, and 95% 6 WAP, respective ly. Seed cotton yields were similar to weed-free cotton with all treat ments except MSMA applied EPD and the LPD treatments, all of which pro vided unacceptable (12 to 49%) control 8 WAP.