施钾肥对烟草白粉病发生的防控效果

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.%[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 a-mount 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.[Con-clusion] It showed that applying the suitable amount of potassium fertilizer could improve the control of tobacco powdery mildew, but the ex-cessive input of potassium fertilizer could increase the occurrence degree of the disease index.