Abstract
Earliness of sucrose accumulation based on pol in juice, time of and duration of physiological maturity were assessed in 12 sugar cane clones from among the commercial (C), high quality (HQ) and high fibre (HF) types present in the germplasm collection at the West Indies Central Sugar Cane Breeding Station in Barbados beginning at six months of growth in plant cane and first ratoon. All clones already possessed sucrose accumulations at six months of growth albeit in different concentrations during both crop cycles. The HQs consistently possessed the largest sucrose accumulations, juice BRIX, field BRIX and purity followed by the Cs and HFs. Over crop cycles, clone, crop cycle differences and clone x crop cycle interactions were significant (P < 0.05); however, the relative rank of clones did not change for pol in juice, field BRIX, fibre and moisture. The mean pol in juice in plant cane was only 1.3 units more than in first ratoon, however, the mean pol in juice of the HFs in both crop cycles were very similar and the decreases were attributed mainly to the HQs and Cs. The HQs generally showed early maturity with HQ6 and HQ10 showing early maturity spanning October to February and November to December, respectively. However, all the HFs and C12 showed similar pol in juice values in January and February. The results of this study show that the crop harvest cycle can be extended to as early as October based on the clones being cultivated. This is the first report of early maturity of sugarcane in the humid tropics. It is hoped that more clones with different times and duration of maturity will be found in the germplasm collection and breeding programmes aimed at optimizing maturity can be initiated.
