Evaluation of sugarcane varieties for maturity earliness and selection for efficient sugar accumulation

Abstract

Aiming at producing adequate sugar yield, the initial selection from 26 varieties of sugarcane (Saccharum hybrids) was made over 14 months of growth on the bases of interrelated juice and sugar parameters including earliness age, high Pol % cane, purity and CCS. Selection standards of 15 Pol % cane, 85 % purity and 14.2 % CCS at maturity allowed the selection of 12 superior varieties including Q77N1232, Q136, Q127, BT65152, Cassius, Cadmus; PS57, PS58, Co6519, C06806, Co997 and Ragnar. Their maturity profiles showed that juice and cane parameters are significantly correlated. The first three varieties, Co 6806, Cadmus and Co 997, matured at <11 months (early maturing), and the remaining nine varieties; PS58, Co6519, BT65152, Q77N1232, Q136, Ragnar, Cassius, Q127 and PS57, matured at ≥11- 12 months (medium maturing). The 12 selected varieties were subjected to further selection based on a selection standard of 17.5 TSH, resulting in selecting eight top-most varieties; Q77N1232, Q127, BT65152, Cassius, Cadmus, Co6519, Co997 and Ragnar. Furthermore, selection based on moderate fibre content set at 14 ≥ fibre % cane allowed for the selection of four best varieties, (Q127, Cadmus, Co6519 and Ragnar). Ragnar, as an ideal variety with high sugar yield, tolerant to drought with medium maturity age and long production period, was taken as a standard, against which the other three varieties possessed higher values of juice parameters, with L14 the highest of all. However, L 14 was sensitive to drought, while the other two varieties were moderate. The superiority of L 14 is hindered by its sensitivity to drought. The overlapping of maturity age and prolonged production periods would prolong the harvesting season and make the cropping season more efficient, as it allows for early harvest, maintaining varietal diversification and sustainable production. The results provide significant information for the possible extension of sugarcane commercial cultivation in Papua New Guinea.