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立枯病是松杉苗木的大敌。东阳第三林埸,在1960年培育的18亩杉苗就有75％发生立枯病。苗木被害后,根頸部或者根部坏死,影响养分、水分的輸送和吸收,以至造成死亡。为了保証綠化造林任务的完成,今后必須千方百計采取措施防治松杉苗木立枯病。兹将松杉苗木立枯病的原因及防治方法簡解如下: 一、立枯病的病狀与病原感染病害的苗木由于生長发育时期与遭受病菌侵袭程度的不同,在苗圃中呈現的病状,一般可分缺苗型、首腐型、猝倒型和根腐型四种。 1.缺苗型:从种子入土到幼苗出土前,种子在土中发芽生長或者尚未发芽时,遭到病菌寄生引起种子、幼芽腐烂,影响出土,在圃地上出現成块的缺苗現象;2.首腐型:种子刚发芽出土时遇到連綿阴雨,病菌侵入幼苗的頂端造成腐烂,以至死亡;3.猝倒
Blight is the enemy of fir seedlings. Dongyang third Linyi, cultivated in 1960, 18 acres of fir seedling blight has occurred 75%. Seedlings killed, the root neck or root necrosis, affecting nutrients, water transport and absorption, as well as death. In order to ensure the completion of the afforestation task, we must do everything possible to take measures to control the seedling blight Songzon fir. The pine seedling blight causes and prevention methods are briefly as follows: First, the symptoms of blight and pathogen infection of seedlings due to growth and development during the invasion of pathogens are different in the nursery presented the symptoms, Generally can be divided into seedling type, the first rot type, cataplexy and root rot type four. 1. The lack of seedlings: seedlings from the soil into the seedlings before excavated, the seeds germinate in the soil or not germinated, the parasitic germs caused by seeds, buds decay, affecting the unearthed in the nursery appeared to block the phenomenon of lack of seedlings; 2. The first rot: the seed just sprouting unearthed continuous rain, bacteria invade the top of seedlings cause decay, and even death; 3. Cataplexy