Effect Of Potassium Nutrition On Elongation And Development Of Cotton Fibre In Bolls At Different Positions And Its Physiological Basis

The experiment was conducted in the scientific farm of Shandong Agricultural University from 2004 to 2005. Two cotton varities, Lu mianyanNO.18 (L18) and Zhong miansuoNO.41(ZH41) with different growth characters and fibre quality, were used and 3 rates of K fertilizer were applied (K2O 60, 180 and 300 kg/hm2) under field condition. Effect of potassium nutrition on Elongation and development of cotton fibre in Bolls at Different Positions and its physiological basis was studied. The main results were as follows:1. Effect of potassium nutrition on growth and development and leaf physiological characteristics of cottonThere was an obvious effects of potassium nutrition on growth and development and leaf physiological characteristics at former stage of cotton. K application increased plant height and leaf numbers per plant, and then with further increasing potassium fertilizer, the ranges of increase were enhanced. but effect on leaf area were not consistent. It appeared to reach maximum area when K application rate was 180 kg/hm2, and then declined with further increasing potassium fertilizer. K application could promote the synthesize of chlorophyll and enhance photosynthesis rate(Pn) of leaves . K application increased the chlorophyll fluorescence dynamics parameters, Fv/Fo, Fv/Fm...