EFFECTS OF LOW NITROGEN STRESS ON EARLY GROWTH, PHYSIO-MORPHOLOGICAL AND QUALITY ATTRIBUTES OF SUGARCANE

摘要

Aims: To understand the performance of sugarcane under LNS and provide some information to evaluate and select high NUE germplasm. Methods & Results: The results of 103 sugarcane germplasm entries at low nitrogen stress for plant and ratoon cane showed that the degree of low nitrogen stress was different to differnet characters, and between plant and ratoon crop. During the early stage, the low nitrogen stress reduced the tillers and shoot number of ratoon cane, and the blade became short and narrow,the area of blade was also decreased. At the reaping stage, the low nitrogen stress decreased the sugarcane yield from 40% to 70%, and the number of millable cane was reduced and the stem diameter became thin. The effects of plant height and stem weighton low nitrogen stress were important for sugarcane yield, and were inconsistent among the germplasm. The low nitrogen stress increased the brix in plant cane but decreased it in ratoon cane. Significance of Study:at the early growth stage than at the late growth stage, and lowere in the plant cane thanin the raroon cane. At the early growth stage, LNS reduced the tillers and shoot number of ratoon cane, the leaf become yellow, short and narrow. At the harvestingstage, LNS reduced markedly the sugarcane yield due to decreasing millable stalks and stalk diameter. From index of yield and stalk diameter, only a few germplasm entries were tolerant to LNS.