SUGARCANE RIPENING TRIALS WITH GLYPHOSATE-BORATE COMPLEX IN COMMERCIAL PLANTATION OF SHANGSI COUNTY, CHINA USING MICRO-LIGHT AIR-CRAFT

摘要

Sugar productivity in major cane growing areas of China hovers between 7 to 8 tons/ha/years, which is low as compared to other progressive cane growing countries. Extensive efforts are being made to improve sucrose content in cane varieties and economic feasibility of non-vconventional technologies such as "Chemical Ripening" is also being explored in commercial sugarcane plantation. In order to advance cane maturity and improve sucrose content during earl milling phase, a ripener complex (300 mg/L glyphosate+400 mg/L boric acid) was applied by A2C Water-Based Over-Light Airplane in 2000 hectares of sugarcane in Shangsi County, China, during 4th week of October, 2003. Simultaneously, this ripener complex was applied through a hand sprayer on sugarcane varieties grown in upland as well as adjacent to paddy fields to assess the accurate physiological effect of ripener. The randomized sampling analysis of varieties ROC10, ROC16 and ROC22 indicated that sucrose % cane in these varieties which have been sprayed with airplane showed average increase to the extent of 1.18% (16.55% vs. 15.37%), 1.30% (16.78% vs. 15.48%) and 0.78% (16.77% vs. 16.21%), respectively, in 30, 45 and 60 days as compared to untreated control. In sugarcane variety which received foliar spray of ripeners through hand sprayers average increase in sucrose % cane was 2.12% (14.76% vs. 12.64%), 2.53% (16.39% vs. 13.86%) and 1.72% (18.04% vs. 16.32) as compared with the unsprayed controls in 30, 40 and 64 days after treatment. The gravity purity of juice was also increased in most of the cases. Based on these experiments it was inferred that the artificial ripening using the above ripener complex was very effective and profitable for sugarcane crop of this areas. Sugarcane grown near irrigated paddy fields showed better results 40 days after ripener's treatment. The highest value of sucrose in cane i.e. 19.83% following ripeners treatment was recorded in this experiment which is never observed in general commercial sugarcane fields in Guangxi area. The artificial ripening using small airplane which was convenient and economical was recommended for commercial sugarcane plantation of Guangxi areas as the milling generally commences in early November (sometimes in late October) when the sucrose content in cane is rather low and recoveries are poor. However, cane areas under artificial ripening should be limited to 1/3 of the total sugarcane plantation with timely harvesting and supply management system.