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(一)螟卵密度及自然寄生率 1.调查对象:新植(冬植)、秋植和宿根这三类蔗田固定田块进行。确定田块时,应根据甘蔗品种、土质类型、植期、田管水平和甘蔗生势等方面都较有代表性的来选取。 2.调查起止时间:当甘蔗萌芽及发株后有二、三片叶时即开始。每十天调查一次。直至甘蔗收获时止(如条件不可能,可调查至甘蔗拔节期止)。
(A) borer egg density and natural parasitism 1. Survey: new plantation (winter planting), autumn planting and perennial three types of cane field fixed field. Determine the field, should be based on sugarcane varieties, soil types, planting, field control and sugar cane potential and so on are more representative to choose. 2. Investigation start and end time: When the sugarcane germination and hair after two or three leaves began. Investigate every ten days. Until the cane harvest time (if conditions are not available, can be investigated until the sugarcane jointing period).