近年来,有不少菜农反映,冬季大棚黄 瓜、西瓜、南瓜等雌花分化少,且大量落花落 果,但并没有发生病虫害,这是什么原因造 成的呢? 一般而言,发生上述情况是因大棚缺 乏光照所致。对大棚蔬菜,菜农总是精心施 肥,防治病虫害,但对于因缺少二氧化碳和 光照造成的“营养不良”就很少顾及了。 二氧化碳是绿色植物进行光合作用, 制造有机营养物质的主要原料之一。在12月份至次年2月份由于温度低,大棚一般采取全封闭方式,隔断了气体交换,得不到外界二氧化碳的补充。白天随着太阳光幅射的增强,棚内温度升高,蔬菜光合作用加强,二氧化碳缺乏比较严重。防止二氧化碳缺乏可采取两种方 In recent years, many farmers reflect the winter greenhouse cucumber, watermelon, pumpkin and other female flower less, and a large number of falling flowers, but did not occur pests and diseases, which is what causes it? In general, the occurrence of the above situation is due to the greenhouse Lack of light due to. Greenhouses, vegetable farmers are always careful fertilization, pest control, but due to lack of carbon dioxide and light caused by “malnutrition,” rarely take into account. Carbon dioxide is one of the main raw materials for photosynthesis of green plants and organic nutrients. In December to February next year due to low temperature, greenhouses generally take a fully enclosed way, cut off the gas exchange, no external carbon dioxide supplement. During the day, with the increase of solar radiation, the temperature inside the greenhouse increased, the photosynthesis of vegetables was strengthened, and the lack of carbon dioxide was more serious. Prevent carbon dioxide deficiency can take two parties