Some Effects of the Ripener Fusilade Super and Drought Stress on Stalk Components and Leaf Emergence of Sugarcane

Sugarcane stalks that were drought stressed and not stressed were sampled 50 days after applying Fusilade Super (fluazifop-butyl). The stalks were sectioned and analysed for structural (fibre) and soluble (brix) carbohydrates. Levels of sucrose, glucose and fructose were determined by HPLC. The data show that total stalk dry matter was not reduced by fluazifop-butyl, regardless of whether the cane was stressed or not. Increases of sucrose in sections of unstressed cane, which were also evident in the top section of stressed cane, were substantial. Lower levels of fibre, glucose and fructose were associated with increases in sucrose. The ripener restricted the emergence of new leaves of stressed and unstressed cane without reducing total green leaf area. From the data presented, some speculations on mechanisms leading to higher sucrose production in unstressed stalks from the application of fluazifop-butyl at a sub-lethal dose are made.