Yield and Quality of Sugarcane (Saccharum officinarum L.) as Influenced by Higher Dose of Potash and Time of Its Application.

Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen. Besides improving many aspects of quality of the produce, it plays a vital role in translocation of sugars and starch formation. A field experiment was conducted at Farm Area, Sugarcane Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan during 2006 and 2007 to study the effect of K₂O level (0, 112, 168 and 224 kg ha^-1) and time of its application (at sowing, at 90 days after sowing (DAS) and half at sowing + half at 90 DAS) on yield and quality of sugarcane. The results revealed that application of potash fertilizer significantly affected the stripped cane yield and all the quality traits of cane except fiber (%). The higher rates of potash application and its splits did not significantly affected the most of the parameters under study however, the maximum stripped cane yield (116 & 107 t ha^-1during 2006 and 2007, respectively) was recorded with the application of 168 kg K₂O ha^-1 in two splits; 84 kg K₂O ha^-1 at sowing + 84 kg K₂O ha^-1 at 90 DAS, while the highest brix (20.4 and 20.8 % during 2006 and 2007, respectively), sucrose (17.5 and 18.2 % during 2006 and 2007, respectively) and commercial cane sugar (12.95 and 13.60 % during 2006 and 2007, respectively) were found with the application of 224 kg K₂O ha^-1 in two splits; 112 kg K₂O ha^-1 at sowing + 112 kg K₂O ha^-1 at 90 DAS. Year effect was significant on brix, sucrose, cane juice purity and commercial cane sugar percentage and all these were more in 2007 than 2006. Contrasts’ analysis revealed that purity percentage as well as the sugar yield can be increased by applying potash in higher amount; however time of its application did show non significant effect on yield and all the quality traits of sugarcane.
Key words: Sugarcane, K₂O, Stripped cane yield, sugar yield, quality