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今年,部分农户种植柴胡虽出苗较好,但死苗亦重,少数甚至出现缺苗断垄。据调查分析,近期柴胡死苗,主要由以下原因引起:1、气候原因。柴胡出苗后,遇异常的持续低温阴雨,日照过少,导致土壤板结,田间湿度过大,柴胡根系发育不良,长势柔弱,抗病力差,甚至烂根死苗。另外,久雨暴晴,沙壤地温度升高过快,小苗、弱苗难以适应气候巨变;或严重草荒地晴天彻底拔除杂草,草间柔嫩弱苗突然暴露于烈日强光下,短时难以适应,都可能导致柴胡突然大片死苗。2、立枯病危害。立枯病为顽固性土传型病害,长期低温阴雨,对立枯病发生有利。据田间调查,柴胡被立枯病浸染后,先是近地表处茎部叶片叶柄变褐色、腐烂或收缩,叶柄受害后,叶
This year, although some farmers planted Bupleurum seedlings better, but dead seedlings are also heavy, and even a few lack of seedlings off ridge. According to the survey and analysis, the recent Bupleurum seedlings, mainly caused by the following reasons: 1, climate reasons. Bupleurum emergence, the case of abnormal continuous low temperature rainy, too little sunshine, resulting in soil compaction, field humidity is too large, Bupleurum dysplasia, weak growth, poor disease resistance, or even root rot. In addition, the long sunny storm, sandy soil temperature rise too fast, seedlings, weak seedlings difficult to adapt to climate change; or severe grassland shortage of sunny weeds, grass suddenly weak weak seedlings exposed to intense sun, short-term Difficult to adapt, may result in a sudden burst of dead wood seedlings Bupleurum. 2, damping off the dangers. Blight is a stubborn soil-borne disease, long-term low temperature rainy season, the occurrence of blight beneficial. According to field surveys, Bupleurum was infected with the dead blight, the first is near the surface of the stem leaves of petiole brown, decay or contraction, petiole victims, the leaves