长江中下游春大豆生长发育特性及与气候因素的关系

我国湖北省宜昌以东长江中下游地区,在6月下旬至7月上旬有大范围的梅雨天气过程;春大豆子熟品种的鼓粒期往往碰上梅雨季节,直接影响干物质积累,导致叶片不同程度恋青,使收获指数偏低,籽粒产量显著下降。从我们研究20个春大豆品种生长发育特性及与气候因素关系的结果表明:气温的高低是影响春大豆营养生长速度的主导因素,随着春季气温的上升,每长一片复叶所需的积温逐渐减少。每日日照时数的多寡是影响生殖发育时期干物质积累的重要因素,而日较差气温和日雨量是通过日照的渠道对干物质积累起间接作用的。因此在春大豆栽培技术上,如何想方设法提高田间气温,增加光照以及使鼓粒期尽可能避开梅雨季节,是增产的关键环节。

GEOWTH AND DEVELOPMENT CHARACTERISTICS AND THEIR RELATIONSHIP WITH CLIMATIC FACTORS OF SPRING SOYBEAB IN MIDDLE AND LOWER YANGTZE RIVER VALLEY

In the middle and lower Yangtze River Valley east of Yichang city of Hubei province the monsoon rain season extends from late June to early July. The maturation period of early spring soybean usually coincides with such monsoon rain. Such coincidente causes reduction of dry matter occumulation of early spring soybean and results in delaying yellowing and defoliation of leaves and reducing harvest index as well as yield. This harmfui effect is for the late spring soybean varieties.Results of study on relationship between climatic factors and proformance growth and development show that air temperature is the primary factor to influence the speed of proceeding of re- productive stage of spring soybean. Along with the rise of air temperature in spring, the cumulative temperature needed for growing of each leaf blade becomes lower consequently. Sunshine hours is an important factor that influence dry matter occumulation in reproductive stage. The indirect effect of day and night temperature difference and amount of daily rainfall on dry matter occumulation is influenced by the length of daily sunshine hours. Management to raise field temperature and sunshine is the key point to promote seed yield of spring soybean.