论文部分内容阅读
北方蔬菜栽培区在早春育苗期间,常常发生苗期病害,严重时幼苗成片死亡,甚至毁种,造成延误农时或影响蔬菜种植计划,因此防止苗病发生、培育壮苗是蔬菜丰产的重要基础。一、蔬菜的主要苗期病害及其发生原因1.猝倒病这是最常见的一类蔬菜苗病,多种蔬菜幼苗都可受害,发病严重时可使幼苗在未出土前即造成烂芽或烂种。但一般于幼苗子叶期或第一片真叶尚未完全展开前较易发病,尤以瓜类幼苗为甚。病苗主要表现为茎基部呈现不正常的浅黄绿色,像被热水烫伤似的,很快转为黄褐色而缢缩,病势发展迅猛,以致子叶尚未呈现萎蔫仍保持绿色时,幼苗便已倒伏而
In the vegetable cultivation area in the north, seedling diseases often occur during the early spring nursery period. In severe cases, the seedlings die or even destroy the seeds, resulting in delays in farming or affecting the planting plan of vegetables. Therefore, preventing seedling disease and nurturing strong seedling are the important foundations of high vegetable yield . First, the main vegetable seedling diseases and their causes 1. Damping disease This is the most common type of vegetable seedlings disease, a variety of vegetable seedlings can be affected, the incidence of severe seedlings can be caused before the unearthed rotten bud Or rotten species. But generally in seedling cotyledons or the first true leaf has not yet fully expanded before the onset, especially in melons are even more. The main symptoms of the disease were that the base of the stem showed abnormally pale yellowish greenish color, scalded like hot water, quickly turned yellowish brown and constricted, and the disease developed rapidly so that when the cotyledons had not yet appeared wilting and remained green, the seedlings had lodged and