论文部分内容阅读
生菜原产于地中海沿岸,性喜冷凉气候。生育适温15～20℃,结球适温10～15℃最高气温25℃以上结球困难。高温长日照促进花芽分化,由于上述生菜生理特性,北京地区夏季栽种结球生菜比较困难;温度稍高就不易结球,日平均气温超过22℃抽苔。尤其水培生菜,由于栽培环境处于温室、大棚等保护地高温条件下,更不易结球,病害严重。
Lettuce native to the Mediterranean coast, a delightful cold climate. Fertility appropriate temperature 15 ~ 20 ℃, the optimal temperature of the ball 10 ~ 15 ℃ The maximum temperature of 25 ℃ or more difficulties in the ball. High temperature and long sunshine to promote flower bud differentiation, due to the above physiological characteristics of lettuce, Beijing summer planting captive lettuce more difficult; the temperature is not easy to catch a little high, the average temperature of more than 22 ℃ bolting. In particular, hydroponic lettuce, as the cultivation environment in the greenhouse, greenhouses and other protected areas under high temperature conditions, more difficult to catch, serious disease.