Paraquat as a Preharvest Desiccant for Sugarcane in Puerto Rico

Abstract

Nineteen sugarcane field trials in the semiarid irrigated, medium- and high-rainfall areas were performed from 1962 to 1974 to evaluate Paraquat (1, 1' dimethyl-4, 4-dipyridinium-bis-dimethyl sulfate, commercially known as Gramoxone) as a desiccant for reducing sugarcane trash. The material was applied by airplane at rates from 0.5 to 4 pt/acre in 4 to 32 gal of water, 2 to 7 days prior to preharvest burning. Paraquat improved burning with significant trash reduction of 3.5% in the 1962-70 trials to 5.08% in 1974. Cane fiber percent cane was reduced by 0.72% in the 1974 trials, with a significant reduction of 1.09% at the four Central Aguirre trials which represented an increase of 4 lb recuperated sugar per ton of cane ground. In general, values for sucrose percent cane, Brix, and purity were not significantly affected by desiccation, especially in 1974 trials, involving 1 pt/acre Paraquat in 8 gal of water. Desiccant effectiveness was influenced by harvest method, the V-cut ter exceeding the machine-loading and the machine cut-and-load methods.