生活在大自然中的绿包植物,有因病毒感染而黄化,也有因营养贫乏而黄化,营养贫乏是一种生理病害(缺素症)。植物缺铁和缺镁都可以发生黄化。在这里着重讨论一下苗圃杨树缺铁及其防治(以下简称黄化病)。今年七至八月份,全地区十一个市县,几乎所有各苗圃都程度不同的发生过黄化病,有不少林场的杨树幼林和果园也有黄化病的出现,发病普遍,危害严重,尤其是大 Green-clad plants living in nature have yellowing due to virus infection, yellowing due to poor nutrition, and poor nutrition as a physiological disease. Plant iron deficiency and magnesium deficiency can occur yellowing. Discussed here about nursery poplar iron deficiency and its prevention (hereinafter referred to as yellow disease). From July to August this year, almost all the nurseries and nurseries of 11 districts and counties in the entire region have had different degrees of occurrence of yellowing disease. There are also many yellow poplar trees and orchards in poplar trees and orchards in many forest farms that have common occurrence and serious harm Especially big