A Study on Response of Sugarcane Genotypes to Phosphorus Fertilizer in Western Guangdong, China

To optimize Phosphorus (P) fertilization, three sugarcane genotypes(ROC22, LC5135, and YT236) widely cultivated in western Guangdong, China wereused for the experiment in which 5 levels of P fertilizer were set up to studythe effects of their application. The results showed that: (1) P fertilization amountwithin 288 kg/hm² P₂O₅ could increase theplant height, stem diameter, and weight and yield of sugarcanes. The yield ofROC22 was 14% more than LC5136 and 33% more than YT236. (2) The sucrose yieldof ROC22, YT236, and LC5136 increased firstly, followed by leveling off or nosignificant change with the increase of P fertilizer. The sucrose yield ofROC22 with 288 kg/hm² P₂O₅ was significantlyhigher than other treatments. The average yield of ROC22 was 15% higher thanthat of LC5136 and 35% higher than that of YT236. (3) The P fertilizer useefficiency of ROC22 and LC5136 increased firstly and then decreased and that ofYT236 always decreased with increasing levels of P fertilizer application.Considering the yields of sugarcane and sucrose and the use efficiency of Pfertilizer, the optimum P fertilizer amounts of ROC22 and LC5136 were 288 kg/hm²and that of YT236 was 192 kg/hm². The growth of ROC22 was betterthan that of LC5136 and YT236.