一、缺素坐苗水稻缺素坐苗,在我省多数发生于山区低产田。主要有三种类型。(一)缺磷发僵:多数发生于早稻和单季晚稻的生长前期。表现稻丛紧束,叶色暗绿,叶尖发紫枯焦,老叶逐渐枯死,延迟抽穗成熟。(二)缺钾赤枯:开始发生于水稻分蘖期,从分蘖盛期至始穗期发生最严重,早稻晚稻都可发生。发病时,叶色灰绿,分蘖少,植株矮缩,从基部老叶逐渐向上发展。由叶尖叶绿发生赤褐色斑点,逐渐扩大造成叶枯,抽穗期明显提早。(三)缺硫发僵:插秧后开始表现,叶色淡黄,叶脉黄白,叶的叶尖都会枯焦,分蘖少,根系暗棕僵硬。一般症状类似缺氮,但施用不含硫的氮肥无效。 First, the lack of planting seedlings sit rice shortage of seedlings, most of the province occurred in the mountain low yield fields. There are three main types. (A) stiff phosphorus deficiency: most occurred in early rice and single season late rice growth early. The performance of rice bundle tight bundle, dark green leaves, the leaves apocynum, old leaves gradually dead, delayed heading mature. (B) red potassium deficiency: began to occur in the tillering stage of rice, tillering from the tillering period to the earliest occurrence of the most serious late rice can occur. Occurrence, the leaf color gray green, less tiller, plant dwarf, from the base of the old leaves gradually upward development. Occurred by the leaves of the leaves auburn spots, gradually expanding to cause leaf blight, heading significantly earlier. (C) lack of sulfur stiff: After transplanting started performance, leaf color yellow, veins yellowish white, leaf tip will be Kujiao, less tillering, root dark brown stiff. The general symptoms are similar to nitrogen deficiency, but use of nitrogen-free sulfur is ineffective.