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利用薄膜的透光性好,能有效地使太阳光转变成热能,有增温、保温的作用。在塑料大棚内,西瓜的播种期和定植期均能提早,实现了早春早熟栽培及提早上市。为了增强保温效果,北方产区出现了“双膜覆盖”、“3膜覆盖”、“4膜1苫”、“5膜1苫”等多层覆盖的栽培模式。1操作要点1.1育苗播种时间一般为12月上旬至2月上旬,多采用嫁接育苗。播种前4~5 d,苗床上排好穴盘,浇透水,然后覆盖地膜,加盖小拱棚,提前加温。同时,做好种子消毒处理,当地温稳定在15℃以上时播种,每个穴孔播1~2粒发芽的种
The light transmittance of the film is good, which can effectively convert the sunlight into heat, and has the effect of increasing temperature and keeping warm. In the plastic greenhouse, watermelon sowing and planting can be earlier, to achieve early spring cultivation and early market. In order to enhance the effect of heat preservation, the cultivation pattern of multi-layer covering such as “double membrane covering”, “3 membrane covering”, “4 membrane 1 苫”, “5 membrane 1 苫” . 1 operating points 1.1 seedling planting time is generally early December to early February, more use of grafted seedlings. 4 ~ 5 d before sowing, the seedbed row of good trays, drenched water, and then cover the plastic film, stamped with small shed, warmed in advance. At the same time, do a good job of seed disinfection, the local temperature stable above 15 ℃ sowing, each hole hole sowing 1 to 2 sprouted species