国外松苗黄化病的防治李长观国外松亩黄化病的特征是：初发期苗木嫩梢针叶叶绿素减少，呈现黄白色，很快发展到全株，以致丧失光合作用能力，造成苗木生长衰弱，直至死亡。如不及时防治就会大面积蔓延，甚至造成整块地苗木枯死。防治措施是：用硫酸亚铁和尿素各０．３％混... Foreign pine yellow disease prevention and control Li Changuan foreign pine acres of yellow disease is characterized by: early emergence of young shoots needle chlorophyll reduction, showing yellowish white, quickly developed to the whole plant, resulting in the loss of photosynthetic capacity, resulting in weak growth of seedlings Until death. If not timely prevention and control will be a large area spread, and even caused the entire piece of seedlings dead. Control measures are: with ferrous sulfate and urea 0.3% mixed ...