Abstract: Field experiment was established in Hebei Province in 2014-2015 and 2015-2016. To clarify the effect of irrigation time, density on wheat yield at different sowing date under irrigation once in spring, experiment was designed by split zone include 3 sowing dates(Oct 10, Oct 15 and Oct 20), 2 different densities at each sowing date planted according to the principle of delayed sowing and densification(330×10⁴ ear/ha and 420×10⁴ ear/ha, 420×10⁴ ear/ha and 510×10⁴ ear/ha, 510×10⁴ ear/ha and 600×10⁴ ear/ha), and one water carried out at 3 different irrigation times (erecting stage, jointing stage and 7 d after jointing stage)in the whole growing period. The result indicated that under irrigating once in the whole growth period, the average yield of wheat decreased with delayed sowing date and densification, but at the same sowing date of two years, wheat yield decreased (-4.5%, -1.8%) with higer density sown on October 10 and increased (4.6%, 1.9%) on October 20, however, difference occurred on October 15 because of different distribution of rainfall, it decreased with higher density under less rainfall before and more after in the whole growth period, otherwise, it increased. For the different irrigation time, wheat yield was the highest irrigating at the erecting stage(7 933.1 kg/ha), and the lowest at the jointing stage sown on October 10, nevertheless, the yield of wheat at jointing stage was the highest at delayed sowing date.Wheat yield of irrigating at erecting stage decreased for sowing with higher density, others decreased first and then increased and there were higher yield and less difference between the density of 330×10⁴ ear/ha and 600×10⁴ ear/ha.For more rainfall before and less after in the whole growth period, yield of different irrigation time showed 7 d after jointing>jointing>erecting and change could not happened in different irrigation time because of increased density. For the three factors of wheat yield, the difference of water at the earlier stage of the whole growth period affected the number of grains per spike, and the increase of spike number was the key to achieve higher yield for late sowing wheat. Therefore, irrigation time should be adjusted according to the rainfall before irrigation and sowing date under one water during the whole growth period, so as to increase the number of ears or grain number per ear and then achieve higher yield of wheat.

Key words: Wheat, Sowing date, Irrigation time, Density, Yield

CLC Number: 

• S512.01