通过长期定位试验和田间试验，研究了缺钾条件下钾素、氯素以及氯化钾对玉米不同抗性品种茎腐病的防治效果，明确钾素和氯素在氯化钾防治玉米茎腐病中的作用。结果表明，施钾可明显增强抗、感病品种抗茎腐病的能力，且对感病品种的防治效果优于抗病品种；施氯对抗、感病品种茎腐病防治效果均不明显。施钾明显增加了吉单180(抗病品种)、吉单327(感病品种)根、茎、叶部的钾素含量，在缺钾条件下，抗病品种较感病品种具有更强的吸钾能力。分析发现，蜡熟期的根部钾素含量与玉米茎腐病的发生率相关最密切，相关系数r=-0.921 8。土壤养分是决定氯化钾中钾素还是氯素发挥主导作用的关键因素。

To elucidate whether potassium or chloride in potassium chloride plays the dominant role in suppression of corn stalk rot, the effects of K, Cl, and KCl nutrition on the stalk rot incidence of resistant and suscepitable cultivars were studied in a 12-year fixed site field trial and a field experiment with K deficiency in soil. The results showed that K application reduced corn stalk rot severity significantly and the control effect on stalk rot of susceptible corn was better than that of resistant corn. K played an important role in suppression of corn stalk rot, but Cl alone had no significant influence on the severity of the stalk rot in Jilin province of China. K application increased K concentration in roots, stems and leaves of resistant and susceptible corn cultivars. In the soil with K deficiency, K-uptake capability of resistant cultivar was higher than that of susceptible cultivars. In addition, statistical analysis significant negative correlation was obtained between incidence of corn stalk rot and K concentration in root of corn at dough stage(r=-0.921 8). And the result proved that the effects of K and Cl fertilizer in reducing corn stalk rot were mainly determined by nutrient status of soil, that is to say, which element in KCl play the dominant role in corn stalk suppression depended on K and Cl status in soil.

国家自然科学基金(30571081)、北京市自然科学基金(6062025)、北京市科技新星计划(2005A60)和中国博士后科学基金(20070410586)项目