由于土传病原菌存在于土壤中,所以一般选择药剂灌根和拌土两种防治方法。灌根处理灌根是将农药药液施于土壤表面或浅层,通过渗漏到达一定的土层深处后发挥药效。不过,由于灌根浓度梯度的存在,在最需要药剂发挥效力的深度,药剂含量则较少,而对病害控制起次要作用的表层,药剂含量却较多,并且表层还会有药剂沉积,使药效不能有效发挥。此外,灌根一般在根基部的一 As soil-borne pathogens present in the soil, so the general choice of medicine irrigation and mixing two methods of prevention and control. Irrigation root irrigation irrigation is the pesticide liquid applied to the surface of the soil or shallow, through leakage to reach a certain depth of the soil to play a pharmacodynamic effect. However, due to the concentration gradient of rooting, the drug content is less at the depth of the effect that the agent needs most, while the surface layer which has a secondary effect on disease control is more, and the surface layer also has drug deposition, So that efficacy can not effectively play. In addition, irrigating roots is generally one at the base