Abstract
The associations between eight yield parameters (stalk length, stalk diameter, number of internodes, internode length, number of green leaves, leaf length, leaf width and number of tillers) and four quality parameters (pol in juice, moisture, field Brix and purity) as well as the interrelationships between yield and six quality parameters (including juice Brix and fibre) were evaluated at maturity in 12 sugarcane clones (Saccharum spp. hybrids) of which four were high fibre (HF), five were high sucrose (HS) and three were commercial (C) types in the plant cane and the first ratoon. The experiment was set in a randomized complete block design with three blocks and three replicates per block. Stalk length and number of tillers consistently showed significant (P < 0.05) negative correlations with pol in juice, field Brix, moisture and purity in the plant cane, first ratoon and over the two crop cycles. Principal component analysis (PCA) showed that the first three, two and three components explained 80.6%, 77.1% and 85.3% of the variation in the data in the plant cane, first ratoon and over the two crop cycles, respectively. PCA showed that all the 14 parameters were significant except stalk diameter, number of green leaves, leaf length and leaf width over the two crop cycles. Stalk length, number of internodes, juice Brix, fibre, pol in juice, field Brix and purity loaded on the first component (45.7% of the variability); and internode length, number of tillers and moisture loaded on the second component (23.1% of the variability). Stalk length, number of tillers, internode length and fibre were positively associated and were negatively associated with juice Brix, field Brix, pol in juice, purity and moisture. The PCA biplot showed that the HF; HS and C clones were generally associated with long internodes and stalks, high fibre and large number of tillers; and high juice Brix, pol in juice, field Brix, purity and moisture, respectively. C12 was also associated with large number of internodes while HS4 and HS8 were also associated with long internodes. Based on the results of this study, a breeding strategy to incorporate desirable characteristics from each clone type towards creation of multipurpose sugarcanes is described.
