发布时间:2025-01-19 02:31:16
冬季清园 花期前喷施四螨嗪、螺螨酯等杀螨卵、若螨剂,这类药一般持效期在60天左右。螨害发生后可选用阿维菌素、哒螨灵、苯丁锡、三唑锡等药剂,但须注意高温。
已知土的粘聚力内摩擦角和作用在土上的压力如何计算土的抗剪强度
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