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是浅层,通过渗漏到达一定的土层深处后发挥药效。灌药处理时药剂到达土壤的深度和量是有一定限度的。此外,灌根一般在根基部的一侧,不能有效地对根进行全面的保护。由于灌根浓度梯度的存在,最需要药剂发挥效力的深度,药剂含量较少,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 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 treatment 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. There is a certain limit to the depth and quantity that the medicament reaches the soil when filling the medicine. In addition, irrigating roots are generally on one side of the root and do not effectively protect the roots effectively. Due to the concentration gradient of rooting, the depth of potency of medicament is the most needed, the content of medicament is less, while the surface layer and medicament which play a secondary role in disease control are more, and the medicament is deposited on the surface, effective