陈娜

摘要[目的]探讨施用钾肥对烟草白粉病的防控效果。[方法]通过田间试验研究施用不同量钾肥对烟草白粉病的防控效果及其机理。[结果]田间施用钾肥能有效防控烟草白粉病的发生。当钾肥用量为150 kg/hm2时，对烟草白粉病的防治效果最好，其病情指数为41.3，显著低于其他处理；钾肥用量为75和225 kg/hm2时的防治效果次之，无钾肥处理效果最差。当钾肥用量为150 kg/hm2时，其烟草生物量最高，烟草叶片的钾含量提高，烟草叶片的总酚和类黄酮含量增加；PPO和PAL活性也显著提高。[结论]施用适量的钾肥能提高烟草白粉病的防治效果，但过量投入钾肥反而加重了病害的发生程度。

关键词 烟草白粉病；钾肥；防控效果；抗病性指标

中图分类号 S435.72 文献标识码 A 文章编号 0517-6611（2017）03-0171-03

Abstract[Objective] The aim was to study control effect of tobacco powdery mildew on application of potassium （K） fertilizer in the field. [Method] We studied the effect and mechanism on application of potassium fertilizer to control tobacco powdery mildew by field experiments. [Result] The application of potassium fertilizer could effectively control the occurrence of tobacco powdery mildew in the field. When the amount of potassium was 150 kg/hm2， the best control effect on tobacco powdery mildew， the disease index was 41.3， significantly lower than other treatments. When the K fertilizer was 75 kg/hm2 and 225 kg/hm2， the control efficiency was the second， and no K treatment was the worst. When the application of potassium was 150 kg/hm2， it could enhance the biomass of tobacco， concentration of potassium in tobacco leaves， also increased the total phenol and flavonoids contents in tobacco leaves；PPO and PAL activity was also significantly increased.[Conclusion] It showed that applying the suitable amount of potassium fertilizer could improve the control of tobacco powdery mildew， but the excessive input of potassium fertilizer could increase the occurrence degree of the disease index.

Key words Tobacco powdery mildew；Potassium fertilizer；Control efficiency；Resistance index

煙草（Nicotiana tabacum）是世界上重要的经济作物。我国是世界上最大的烟草生产国，种植面积和产量均居世界第一位[1-2]。贵州省是我国重要的烟草生产省份，源于其优越的自然生态条件，年均气温10～20 ℃，年均积温4 500 ℃，适宜烟草的种植[2-3]。贵州省烟草的生产总量占全国的15%左右[4]。长期以来，随着贵州省烟草种植业的发展，其病虫害发生也愈加严重，其中烟草白粉病（Erysiphe cichoracearum）是生產上的主要病害之一，在贵州烟草种植区域发生普遍[5]。烟草白粉病通常从下部叶片开始发生，自下而上蔓延，发病严重时叶片全部脱落[2]。贵州烟草种植地区受天气和耕作制度等因素的影响，白粉病在种植区域连年发生，制约了烤烟产业的发展。目前，防治烟草白粉病主要是喷施农药，但会影响烟草的品质，因此，需要寻求一种有效的防治方法，在保证烟草品质的同时也能有效防治病害。……