Influential factors of yield of winter wheat varieties sowed in spring in northwest plateau of Hebei Province

The experiment was carried out to study the influences of variety,sowing time,sowing rate and soil type on the yield and its components of winter wheat sowed in spring.It was shown that the proper sowing rate was 0.25 million grains/666.7m~2.The order of effects of other three factors on yield of winter wheat was: soil typesowing datevariety.The yield in shoaly land was higher than that in sand land.With the sowing date delayed,the yield,the number of ears,the grains per ear and 1000-kernel weight were reduced.Among the three tested varieties,the yield of Yumai 13 was the highest.