Optimum time of harvest for high early ccs sugar varieties

To assess the optimum time of harvest for high early-CCS varieties, two experiments involving a range of varieties were conducted on the Bundaberg Sugar Experiment Station. The first included autumn and spring planting with monthly harvests from May to September in plant, first and second ratoon crops. Data on cane yield and CCS for each harvest date allowed assessment of the benefits of high earJy-CCS varieties for extending the harvest season and for increasing productivity during the normal harvest season. The second compared variety performance under green cane trash blanketing and conventional burnt cultivation for early season harvesting in May and June. High early-CCS varieties gave higher CCS and sugar yields for early harvests and higher overall crop cycle CCS and sugar yields than mid- to late-season maturing varieties. Gross returns were calculated for a range of early season harvesting strategies. Results indicated a significant reduction in returns for a May to September harvest season compared to June to September. The inclusion of high early-CCS varieties increased gross returns significantly, being greatest where the recently released high early-CCS varieties Q151 and Q155 were harvested selectively in May and June. In general, CCS was reduced in first ratoon under trash blanket compared with burnt cane, while both CCS and cane yield were higher under trash blanket in second ratoon. Q155 showed a positive response in first ratoon as well as the greatest overall response to trash blanketing.