杏树根腐病是杏树苗木及幼树上发生的一种新型病害,并有蔓延的趋势。在河北、辽宁、山西等地均有发生。在苗圃重茬繁殖的杏苗和大龄杏树行间培育杏苗时,易发病、死苗。由于该病潜伏期较长,在树势衰弱,土肥水管理跟不上时,即易发病,轻者影响生长和结果,重者树体死亡。该病除危害杏幼树及苗木外,还危害苹果、梨、桃和葡萄幼树及苗木。 一、病害症状及发病规律 杏树根腐病菌通过雨水及土壤传播,先从须根侵入,发病初期,须根出现棕褐色圆形小斑,随着病情加重,病斑加大,连接成片,并传染主根、侧根,开始腐烂。韧皮部变褐,木质部坏死,变黄或腐烂。地上部症状表现为:①叶片焦边型。主要在当年生新 Apricot root rot is apricot seedlings and saplings occurred on a new type of disease, and there is a tendency to spread. In Hebei, Liaoning, Shanxi and other places have occurred. Cultivation of apricot seedlings in the nursery and recuperation of apricot seedlings between the rows of apricot, prone to disease, dead seedlings. Due to the latent period of the disease is longer, when the shrubs are weak and the fertilizer and water management can not keep up, it is easy to get sick and the light affects the growth and the result. In severe cases, the tree body dies. In addition to the disease endanger apricot saplings and seedlings, but also endanger apple, pear, peach and grape young trees and seedlings. First, the symptoms and incidence of disease Apricot root rot pathogens through the spread of rain and soil, the first from the fibrous roots invasion, early onset, fibrous sepia appear small round spots, with the aggravating disease spots, connected into pieces, and Infected the main root, lateral root, began to decay. Phloem brown, xylem necrosis, yellowing or decay. Symptoms of symptoms above the ground: ① leaves focal type. Mainly new students in that year