Studies were conducted in 1999, 2000, and 2001 to evaluate cotton response to CGA 362622 applied postemergence with various adjuvants. In field studies, CGA 362622 was applied at 3.8 or 7.5 g ai/ha with nonionic surfactant, crop-oil concentrate (COC), or a urea-based adjuvant. A nontreated control was maintained weed free for comparison. Crop injury over all years at 1 wk after treatment (WAT) was 27 and 34% from 3.8 and 7.5 g/ha CGA 362622, respectively, when rates were pooled over adjuvants. At 4 WAT, injury was 6 to 14% with 3.8 g/ha and 10 to 21% with 7.5 g/ha CGA 362622 during the 3-yr study. Cotton heights at 2 WAT were reduced by 16 to 31% of nontreated cotton heights by CGA 362622. Heights of treated cotton did not differ and were generally equivalent to the nontreated control at 8 WAT. Cotton injury and height reduction were greatest when CGA 362622 was applied with COC. Cotton lint yields and fiber quality were not affected by CGA 362622 rate or adjuvant treatment. Cotton injury from CGA 362622 in the greenhouse was similar to that in the field. Initial cotton injury and subsequent reduction in leaf area or shoot dry weight were generally lowest when CGA 362622 was applied with no adjuvant or UBA in the greenhouse.
Nomenclature: CGA 362622 (proposed common name trifloxysulfuron sodium), N-[(4,6-dimethoxy- 2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluoroethoxy)-pyridin-2-sulfonamide sodium salt; cotton, Gossypium hirsutum L. ‘SureGrow 125.’
Additional index words: Sulfonylurea herbicide.
Abbreviations: ALS, acetolactate synthase enzyme (EC 188.8.131.52); COC, crop oil concentrate; MSO, methylated seed oil; NA, no adjuvant; NIS, nonionic surfactant; OSS, organosilicone surfactant; POST, postemergence; UBA, urea-based adjuvant; WAT, weeks after treatment.