论文部分内容阅读
果树黄叶病的发病原因,是由于土壤中可溶性二价铁转化成不溶性的三价铁沉淀在土壤中,造成果树不能吸收和利用,导致果树发生的生理性病害。果树黄叶病一般从新梢顶端的嫩叶开始发生,叶肉变为黄色,叶脉两侧仍保持正常绿色,使叶片出现绿色网络状,随病势发展叶片失绿程度逐渐加重,叶脉迹褪绿,全叶呈黄白色,甚至整叶变成白色,在失绿部分还出现锈褐色枯斑,或叶绿焦枯,数斑相连,使叶片大部分焦枯引起落叶,从顶部出现焦稍枯顶,树势逐渐衰弱而死亡。针对果树发病原因和发病程度,对发病重的树可采用输液法进行急救。操作方法是:在树冠垂直的下方,控出粗1厘米左右的根,切断后,插入装有
Fruit tree yellow leaf disease is due to the soluble ferrous iron in the soil into insoluble ferric iron precipitation in the soil, resulting in fruit trees can not be absorbed and utilization, resulting in physiological occurrence of fruit trees. Yellow leaves of fruit trees generally start from the tip of young shoots, leaves turn yellow, leaves remain normal on both sides of the green, so that leaves appear green network, with the development of disease leaves greenish degree gradually aggravated, The whole leaf is yellowish white, and even the whole leaf turns white, rust brownish brown spots appear on the greenish part, or the leafy green coke is dry and the spots are connected, causing most of the leaves to scorch and cause deciduous leaves. Gradually weakening the potential death. For the causes of disease and the incidence of fruit trees, the incidence of heavy trees can be used infusion method for first aid. The method of operation is: below the vertical crown, control the root about 1 cm thick, cut off, insert with