Five doses (50, 100, 200, 300, and 375 cc/ha) of DROPP⁷ ULTRA, FINISH⁷ + DROPP⁷ ULTRA (2 l/ha + 50 and 300 cc/ha), were applied at two defoliation dates (at 40 and 80% of open bolls) in DELTAPINE 5415. These treatments were compared with the regional check DROPP⁷ (150 g per ha), DEF⁷ (2 lt/ha) and a treatment without defoliation. This experiment was carried out in Yaqui Valley Experiment Station in 1998. The defoliation treatments were analyzed under an experimental design of randomized blocks with three replications. Higher defoliation percentages were achieved in treatments of 200 cc/ha or higher of DROPP^(R) ULTRA and regular ones with DEF⁷. DROPP⁷ ULTRA and FINISH⁷ combination did not seem to improve defoliation. No significant yield difference between defoliation treatments was observed, also, there is no negative effect of defoliation on yield components and fiber quality.