Effect Of Ethephon On The Physiological Biochemical And Agronomic Characters In Ratoon Crop Of Sugarcane

The plant cane of two sugarcane varieties, GT17 and ROC22, was sprayed with 100 mg/L ethephon at tillering stage, which promoted the sprouting of the next ratoon crop and increased the chlorophyll content in the leaves at young stage. The ratoon cane continuously was treated by spraying 0 mg/L and 100 mg/L ethephon at young and booming stages, respectively. The results showed that the ethephon treatment at young stage promoted the ratoon cane growth, improved the economic characters including cane yield. Both the ethephon treatments at two stages increased the millable stalks and the ratio of millable stalks to total young shoots, and improved the sucrose % cane and decreased the reducing sugar in the juice. But the ethephon treatment at booming stage decreased the stalk length, stalk diameter and stalk weight as compared with the control. During relative drought stage, the plants with ethephon treatment showed higher stalk elongation rate, relative water content, chlorophyll contentand ratio of bond water/free water, and lower malondiadehyde, soluble sugar and electrical conductance in the extracted solutions. The photosynthesis characters of single and colony are polished up that the ethephon treatment ratoon crop of sugarcane at the same time. The plants with ethephon treatment showed higher the net photosynthetic intension and the original light energy conversion efficiency (Fv/Fm) and Fv/Fm ratios and lower FO values, which suggested that the ethephon treatment improved the drought resistance of the ratoon cane.