The Effect Study Of Soil Toxic Substance On Young Shoot Etiolation Of Ratoon Sugarcane

Recently, the young shoot etiolation of ratoon sugarcane has happened in many sugarcane areas, which has influenced the yield and quality of the sugarcane.In order to provide the reasons of the ratoon sugarcane seedings etiolation, curb it spreading, the experiment had been investigated four region:Wuxu, Quli, Changping and Xinning, where etiolation phenomenon is serious, then soil, leaves and roots samples were collected form normal fields, etiolated fields and new planting sugarcane fields, and their physiological and biochemical indicators were analyzed. The condition, activity, and membrane permeability of roots system, and chlorophyll content, nitrate reductase activity, active Fe content, active Mn content, total Fe content, total Mn content, total S content, total Al content of leaves, and pH, catalase activity, urease activity, organic acids, phenolic acids of soil had been analyzed, the results showed:(1) Continuous cropping for a long time lead to phenolic acids accumulate, which infected roots system, so that the membrane permeability of roots system increased, a lot of contents exuded. The dead root cells and root secretion could accelerate accumulation of toxic substances.(2) The plants absorbed excess Mn and Al, which reduced the nitrate reductase activity, controlled the nitrogen metabolism of sugarcane. The germination and growth of new roots were controlled because the plants were growing poor.(3) The proportion of Fe and Mn was disappropriate in the plants, which hindered the sugarcane form absorbing and activating Fe. At last, the ratoon sugarcane young soot went to etiolate for short of Fe.