Abstract: This experiment was conducted to study the effect of potassium fertilizer on growth and leaf physiological characteristics at seedling stage of different cotton varieties under field conditions. Two rates of potassium fertilizer were applied and three materials(L21,L22 and L28) were used in this design. The result showed that applicanon of potassium fertilizer to varying degrees increased plant height, leaf number, leaf area per plant and the last fourth leaf area of different cultivated varieties at seedling stage. Potassium fertilizer application promoted the synthesizing of chlorophyll and the improvement of photosynthetic rate of functional leaf, increased the value of Fv/Fn and Fv/Fm,and improved the effect of ETR and中PII .Meanwhile,when potassium fertilizer applied,SOD and CAT activity were enhanced, yet POD activity and the content of MDA were decreased,which caused the long duration of functional leaf. Although characteristics improved in both potassium fertilizer application manners,the higher quantity one took a better effect. As for different cotton varieties L22 exhibited the most sensitiveness to potassium fertilizer application manners,followed by L21 and L28.

Key words: Cotton varieties, Potassium, Seedling stake, Leaf physiology, Growth and development

CLC Number: 

• S562.01