Method for evaluating sugarcane defoliation by utilizing stem sheath different-speed growth and separation layer malonaldehyde content

The invention discloses a method for evaluating sugarcane defoliation by utilizing stem sheath different-speed growth and separation layer malondialdehyde content, and relates to the technical field of sugarcane defoliation evaluation. The method comprises the following specific steps: (1) taking a sheath diameter, an internode diameter, a sheath inclination angle and separation layer malondialdehyde as evaluation indexes; (2) observing the evaluation indexes; and (3) according to observation results of the evaluation indexes, dividing the sugarcanes into an automatic defoliation type variety, a difficult-defoliation type variety and an easy-defoliation type variety. According to the method, the leaf sheath diameter, the internode diameter, the leaf sheath inclination angle and the separation layer malondialdehyde are innovatively adopted as evaluation indexes to comprehensively evaluate the sugarcane defoliation property according to the characteristic that the loose degree of the leaf sheath phimosis of the