Sugarcane (Saccharumspp.) Response to Simulated Fluazifop-P Drift

Abstract

The impact of POST applications of fluazifop-P on sugarcane grown in Louisiana was determined for 3, 6,11, 22, and 44% of the lowest rate recommended for the control of johnsongrass in soybean (100 g ai ha−1). In field studies, sugarcane injury 4 WAT increased as the rate of fluazifop-P increased. Injury in excess of 80% was observed when fluazifop-P at 44 g ha−1was applied in May and June and 54% when applied in August Sugarcane stalks treated with fluazifop-P were fewer in number, shorter and lighter, and immature at harvest This resulted in lower Brix and sucrose levels, higher fiber content, and ultimately lower sugar yields. Reductions in sugar yields associated with an application of fluazifop-P closely paralleled visual injury 4 WAT. Injury from application of fluazifop-P was also evident in the subsequent ratoon crop where reductions in spring shoot counts of 14 to 25% were obtained even when fluazifop-P had been applied at 6 g ha−1the previous year. Greenhouse studies indicated that the response observed in the field with CP 70-321 sugarcane was indicative of the major cultivars grown, with the possible exception of CP 74-383.