研究播期和生态点对半冬小麦产量的影响对小麦产量提高具有重要意义。本研究旨在探讨稻-麦轮作条件下播期和生态点对小麦产量以及相关气候资源的影响。试验以两个半冬性小麦品种为材料，分别在东海县和建湖县开展，共设置6个播期。第一播期(S1)基本苗300×10⁴ ha^-1，每推迟一个播期(S2-S6)基本苗分别增加10%。结果表明，播种期的推迟，导致整个生育期天数缩短、有效积温和累计太阳辐射降低。S2~S6产量较S1分别降低了0.22～0.31t ha^-1、0.5～0.78t ha^-1、0.86～0.98t ha^-1、1.14～1.38t ha^-1和1.36～1.59t ha^-1。同一播期，随着生态点北移，生育天数增加，日均温和有效积温降低，累积辐射增加。结果表明，相同播期，东海县的产量比建湖县低0.01 ~ 0.39 t hm ^{- 2}。有效积温、累积辐射与产量呈显著正相关。日均温与产量呈显著负相关。籽粒产量下降的主要原因由于日均温的升高和有效积温的降低导致穗粒数和千粒重下降引起的。

Exploring the effects of sowing date and ecological points on the yield of semi-winter wheat is of great significance.  This study aims to reveal the effects of sowing date and ecological points on the climate resources associated with wheat yield in the Rice–Wheat Rotation System.  With six sowing dates, the experiments were carried out in Donghai and Jianhu counties, Jiangsu Province, China using two semi-winter wheat varieties as the objects of this study.  The basic seedlings of the first sowing date (S1) were planted at 300×10⁴ plants ha⁻¹, which was increased by 10% for each of the delayed sowing dates (S2–S6).  The results showed that the delay of sowing date decreased the number of days, the effective accumulated temperature and the cumulative solar radiation in the whole growth period.  The yields of S1 were higher than those of S2 to S6 by 0.22–0.31, 0.5–0.78, 0.86–0.98, 1.14–1.38, and 1.36–1.59 t ha^–1, respectively.  For a given sowing date, the growth days increased as the ecological point was moved north, while both mean daily temperature and effective accumulative temperature decreased, but the cumulative radiation increased.  As a result, the yields at Donghai County were 0.01–0.39 t ha^–1 lower than those of Jianhu County for the six sowing dates.  The effective accumulative temperature and cumulative radiation both had significant positive correlations with yield.  The average temperature was significantly negatively correlated with the yield.  The decrease in grain yield was mainly due to the declines in grains per spike and 1 000-grain weight caused by the increase in the daily temperature and the decrease in the effective accumulative temperature.