Abstract:

In order to explore the suitable combination of sowing dates and planting density under the condition of climate change, a field experiment with three factors split plot design was conducted at Shangqiu City of Henan Province during 2008-2009. The main plots were two varieties of ‘Aikang58’ and ‘Yunong949’, the subplots were five sowing dates of October 6th, 13th, 20th, 27th and November 3rd and the split plots were three planting densities of 60, 120, 180 kg/hm2. The results showed that the yield of ‘Aikang58’ was higher than ‘Yunong949’ by 597.30 kg/hm2. Maximum yield of semi-winter wheat ‘Aikang58’ appeared in October 6th, and maximum yield of weak spring wheat ‘Yunong949’ appeared in October 20th. After October 20th, with the delay of sowing date the grain yield dropped significantly. Sowing at October 6th, October 13th, October 20th the wheat had higher production with planting density of 60 to 120 kg per hm2. While sowing at October 27th, November 3rd the wheat could obtain higher production with planting density of 120 to 180 kg per hm2. Through the analysis of the combination of density and seedtime, the reasonable sowing dates were during the first and second ten days of October. And planting density of 60 to 120 kg per hm2 was more appropriate. With the delay of sowing dates the total growth period of wheat was shorten, but the shorten days were less than delayed days. Planting density has little influence on growing period. The appropriate sowing time was helpful to increase the total stalk number and LAI. Sowing late properly can reduce invalid tillers and leaf area to raise spike rate.