A.5%~10%B.10%~15%C.15%~20%D.20%~30%
A.秋末深耕苗圃地殺死越冬蟲(chóng)態(tài)B.造林前適時(shí)整地C.灌水溺死幼蟲(chóng)D.及時(shí)清除苗圃間及周圍雜草