一、死苗原因 (一)低温引起的生理死亡,一般发生在寄栽后2～5天。秧苗由于抗性较低,遇到强寒潮转晴时,根系吸收能力弱,叶片蒸腾失水,使体内水分代谢失去平衡,造成卷叶青枯死苗。 (二)侵染性病毒。寄栽秧苗的受到严重低温影响后,活力下降抗逆力减弱,绵腐菌、腐霉菌、稻瘟病等有害微生物趁虚而入,造成病害死苗。 First, the reason of dead seedlings (A) physiological hypothermia caused by death, usually occurs in the 2 to 5 days after planting. Seedlings due to lower resistance, encountered strong cold to sunny, the weak absorption capacity of the roots, leaf transpiration dehydration, so that the body loses its balance of water metabolism, resulting in leaf blight dead seedlings. (B) of the infectious virus. Seedlings planted seedlings affected by the severe low temperature, the decline in vitality weakened resilience, cotton rot fungus, Pythium, rice blast and other harmful microorganisms take advantage of, resulting in disease dead seedlings.