杭州地区桑树冬芽萌发进程与春季气象条件的关系分析

Relationship between Sprouting Courses of Mulberry Winter Bud and Meteorological Condition in Spring in Hangzhou Region

通过相关分析和通径分析,表明在杭州地区的气候条件下,气温是桑树冬芽萌发的主导因子。日照和降水通过气温而起作用。3月平均气温提高1℃,乌皮桑、荷叶白和一之濑的脱苞期分别提前3 d、5 d和3 d;燕口期分别约提前3 d、4 d和4 d;开叶期分别约提前4 d、5 d和4 d。从脱苞至开叶的天数平均为13 d、10 d和7 d。气温高从脱苞至开叶的天数少,以乌皮桑对气温的反应最敏感。分析结果指出春季稳定通过10℃的始日可作为桑树生长季开始的指标。春季气温呈波状形上升,桑树生长也表现为阶段累积生长。

The correlative coefficients and path coefficients between main climatic factors and sprouting stage of mulberry are analysed. The results show: under the climatic condition in Hangzhou region, air temperature is the key factor that affects sprouting of the winter bud. But it is through air temperature that sunshine duration and rainfall affect the sprouting. When monthly mean tempe- rature in March rises 1℃, green tip sprouting stage of Wu Pi Sang, He Ye Bai and Ichinose will be earlier respectively by 3, 5 and 3 days; the sprouting stage of the bud showing swallow-bill shape is earlier by 3, 4 and 4 days; the ope- ning stage of leaf is earlier by 4, 5 and 4 days. The mean duration of Wu Pi- Sang, He Ye Bai and Ichineose from green tip sprouting stage to opening stage of leaf is respectively 13, 10 and 7 days. The higher the temperature is, the less the days from green tip sprouting stage to opening stage of leaf is. Wu Pi Sang is the most sensitive to temperature. The initial date when the daily mean air temperature is steadily above 10℃ can be considered as an index that mul- berry starts growing. In spring the air temperature rises in a fluctuating way and mulberry grows by stages.