Effects of spraying ethephon on the canopy structure and the physiological indexes for drought resistance in sugarcane

Two sugarcane varieties, GT11 and ROC20, were grown in the field. Ethephon of 100 mg/ L was sprayed on the leaves at the early elongation stage. Some physiological indexes for drought resistance at the mid-late stage and the canopy architecture at the processing ripening stage were measured. The results showed that, under the stress of soil moisture, the ethephon treatment improved the canopy architecture at the processing ripening stage, and increased the bound water content and the ratio of bound water to free water, and significantly retained their stability as compared with the control, and increased the chlorophyll content, retained its relative stability and it was more effective in GT11. The ethephon treatment also increased the proline content in the two varieties and retained relative stability of proline content in ROC20. As a result, the ethephon treatment increased the drought resistant ability of the two sugarcane varieties and improved the cane quality in GT11 as compared with the control.