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观察 了菵草 发生消长 规律，生 育期及不 同播种 深度出苗 情况，调 查了田间 菵草发生 与危害，对 菵草种群 发生量呈 上升的 原因进行 了分析 ，并提出了 对菵草 的防治对 策。
The law of growth and development, the growth period and the emergence of seedlings at different planting depths were observed. The occurrence and damage of the seedlings were also investigated. The reasons for the increase of the seedlings occurrence were analyzed and the control strategies were proposed.