塑料大棚内蔬菜氨气中毒原因及预防□刘东林孙忠艳在塑料大棚内的蔬菜，尤其是黄瓜、西红柿，有时叶片会形成不定形褪色，从叶缘到叶片，甚至茎秆都出现水浸状萎蔫，继而坏死变褐，在靠近地面的老叶上症状更为明显，叶面似水烫状，进而叶脉变白。这种现象，越是天气寒冷，... Causes and Prevention of Ammonia Ammonia Poisoning in Plastic Greenhouses □ Liu Donglin Sun Zhongyan Vegetables, especially cucumbers and tomatoes, in plastic greenhouses may sometimes form faded fading from leaves to leaves or even stems, Then necrosis browning, the old leaves near the ground on the more obvious symptoms, like hot watery leaves, and thus white veins. This phenomenon, the more cold weather, ...