关键词: 稻茬麦, 播期, 产量, 灌浆期, 高温, 气象因子, 通径分析

Abstract: Aiming at high temperature stress problem at grain filling stage of post-paddy wheat in southern Henan，the winter wheat yield and its relationship with meteorological factors were studied under different sowing dates from 2015 to 2017，so as to find the suitable sowing date to avoid high temperature stress at grain filling stage.The results showed that compared with other sowing dates，the treatment with sowing date of mid October had lower mean daily temperature and mean daily relative humidity，but more sunshine and rainfall at grain filling stage; the treatment with sowing date of late October had more sunshine; the treatments with sowing date of early and mid November had higher temperature and less sunshine at grain filling stage.The grain yield and its components decreased with the postponement of sowing date，the yield of the treatment with sowing date of mid October was the highest，increased by 1.64%—129.61%，the spike number increased by 3.06%—73.25%，the 1 000-grain weight increased by 1.44%—24.98%，and the grain number per spike increased by 5.62%—32.71% compared with other treatments.The results of path analysis showed that the mean daily temperature and mean daily relative humidity had negative effect on 1 000-grain weight and grain number per spike，the sunshine hour had positive effect on 1 000-grain weight and grain number per spike from 2015 to 2017.The diurnal temperature range had positive effect on 1 000-grain weight and grain number per spike，but the rainfall had negative effect on grain number per spike from 2015 to 2016.The diurnal temperature range had no significant effect on 1 000-grain weight and grain number per spike，and the rainfall had positive effect on 1 000-grain weight and grain number per spike from 2016 to 2017.It could be seen that the main meteorological factors limiting the increase of 1 000-grain weight and grain number per spike of winter wheat were high temperature and high humidity，and the main meteorological factor that had positive effect on the 1 000-grain weight and grain number per spike of winter wheat was sunshine hour.In conclusion， the diurnal temperature range，rainfall and sunshine hour of the treatments with the sowing date of mid and late October were higher at grain filling stage，which had greater direct positive effects on 1 000-grain weight and grain number per spike，and relived the negative effect of high temperature and humidity.The temperature and humidity were high，and the sunshine hour and diurnal temperature range were low， which had higher negative effect on 1 000-grain weight and grain number per spike under the sowing date of early and mid November，so the yield significantly decreased．

Key words: Post-paddy wheat, Sowing time, Yield, Grain filling stage, High temperature, Meteorologi cal factors, Path analysis