播种期对广东省晚稻产量及生育期的影响

为了研究出广东省5个典型稻作生态区晚稻最佳播种期，明确气候变化对近年来新育成并大面积推广晚稻品种产量的影响。2009年晚季，在韶关、肇庆、广州、汕头、湛江等5个代表性地点对超级杂交稻天优998、超级常规稻玉香油占及杂交稻天优428进行了分期播种试验，结果表明：播种期对广东晚稻产量及其构成因素的影响具有一定的地域性差异，其中，5个地点高产播种期分别为7月2日（B）、7月16日（D）、7月16日（D）、7月23日（E）、7月9日（C）。通过分析晚稻产量及其构成因素与温度、降雨、光照等气候生态因子的相互关系、构建逐步回归方程，结果表明，返青期至拔节期较低的日均最高气温、较低的日均最低气温、较高的日均气温及较高的积温，孕穗期至齐穗期较高的日均气温、较低的平均日照时数，以及齐穗后20天至收割期较大的累积日照时数，有利提高晚稻产量。

Effects of Sowing Date on Yield and Growth Period of Late-season Rice in Guangdong Province

The main task of this study was to choose the best sowing date for late-season rice grown in 5 typical rice ecological zones in Guangdong Provinces and research impacts of climate change on yield of late-season rice cultivars released in recent years and widely used in commercial production. The interval sowing experiments were conducted by using super hybrid rice combinations ‘ Tianyou998 ’ , super rice cultivar ‘ Yuxiangyouzhan ’ and one hybrid rice cultivar ‘ Tianyou428 ’ , grown in 5 locations e.s. Shaoguang, Zhaoqing, Guangzhou, Shantou, Zhanjiang, in 2009 late season. There were differences in effects of sowing date on yield and its components depending on the geography, especially the optimum sowing date of different location were July 2 nd （B）, July 16 th （D）, July 16 th （D）, July 23 rd （E）, July 9 th （C）, respectively. This study also analyzed the relationships between yield ’ s components and the environmental factors including temperature, precipitation, illumination and established stepwise regression equations, the results showed that periodic changes in weather environment, such as lower mean daily maximum temperature, lower mean daily minimum temperature, higher average day temperature and accumulated temperature, from reviving stage to the jointing stage, and higher average temperature and less average day sunshine hours from booting stage to heading stage, and more accumulated sunshine hours, were conductive to increasing late-season rice production.