Changes in the Components of Sugarcane Stalks from Ripening with Fusilade Super

The effects of the chemical ripener, Fusilade Super, were evaluated over time in order to characterise the response curves of sucrose, fibre and non-sucrose content. This was done to provide a comparison between the responses in terms of sucrose mass and ERC (estimated recoverable crystal) mass. The ERC formula is used as a surrogate for RV (relative value) so that the benefits from Fusilade Super could be quantified in terms of the RV payment system. The raw data of sucrose, fibre and non-sucrose from a single experiment at Pongola on stress–free NCo376 were normalised and responses were constituted as the difference between treated and control values expressed as a percentage of control. A second set of data from 13 experiments were collectively analysed in the same manner for sucrose mass responses. Response curves of sucrose mass were related to radiation Rad, thermal time TT10and evapotranspiration ETref accumulated after spraying as a means of producing a base for developing more appropriate time intervals between spraying and harvesting. Data from the experiment at Pongola showed that the fibre and non-sucrose content were reduced by about 10% while sucrose content increased by 15% on a dry matter basis, 58 days after spraying Fusilade Super. The changes in the partitioning of stalk components resulted in an increase of 27% in sucrose mass and 30% ERC (estimated recoverable crystal) mass. Peak response occurred when accumulated TT10 = 500 o C days, ETref =165 mm and Rad = 820 MJm ̄2. These values were different for the extended data set.