新疆北部20年棉花物候计算和分析——以炮台镇为例

Calculation and analysis of cotton phenology in the Northern of Xinjiang

基于singlesine物候模型计算新疆北部 2 0年棉花日度累积值 ,利用系统聚类法分析 2 0年棉花物候变化规律 ,建立了物候日度和棉花产量之间的回归模型。结果表明 :新疆北部棉花主要物候事件播种、出苗、现蕾、开花、裂铃、吐絮和停止生长所需要的日度累积值分别为 5 3.185 3.18、10 9.99、36 0 .97、6 35 .6 4、116 9.6 1和 1180 .0 2日度 ;聚类分析将 2 0年划分为 4个类型即冷年类型、温暖类型、热年和特热年 ;棉花产量 (y)和全年日度累积值 (x1)、棉花停止生长日度累积值 (x2 )和 9月份以后的日度累积值 (x3 )之间存在正相关。

A single sine model is developed that calculates the accumulated degree days(DD) of cotton development stages, the change rule of cotton phenology in 1980～1999 years is done by the cluster analysis with complete linkage method(CLM), simultaneously, the regression model between cotton yields and degree days is realized. The result shows approximately 53.18,109.99,360.97,635.64,1169.61 and 1180.02DD are the requirement degree days for seed, seedlings, showing bud, flower, splitting boll, opening boll, and stopping growth, respectively. The accumulated degree days of cotton growth are varied in 4～5 years periodicity. In early cotton stages, seed and seedlings stages, variability of degree days is bigger than that of other cotton stages, Coefficient of variations are 44.1 and 30.4 percent in seed and seedling stages. Four type, cool, warm, hotter and hottest year, is clustered via CLM. Cotton yields(y) and accumulated degree day for whole year(x 1), stopping growth period(x 2) and post september(x 3) is correlated positively. The regression equations is y=-2101.75+2.379x 1,y=-2169.35+2.446x 2 and y=167.70+7.339x 3, respectively. In hotter and hottest years, cotton yields are higher than that of cool and warm years. To apply sums of degree days of cotton stages and manage cotton growth and production, it is better than calendar time.