Effect of Nitrogen Topdressing Time on the Accumulation and Transfer of Nitrogen, Yield and Protein Content in Specialty Wheat

A field experiments was carried out to investigate the effects of nitrogen topdressing time on the (nitrogen) accumulation and transfer, grain yield and protein content of two specialty wheat cultivars, Xumai 26 and Huaimai 18 under high yield conditions. The results showed that the nitrogen topdressing at jointing and (booting) stages increased the grain yield and protein content but the topdressing at heading and flowering stages might be unfavorable to simultaneously increase the yield and protein content. Compared with the (no-topdressing) treatment, the topdressing treatments significantly increased (post-anthesis) (nitrogen) (assimilation) of Xumai 26, decreased the transfer of reserved nitrogen in vegetative organs to the grain but increased that in Huaimai 18. The correlation analysis showed that grain protein content of Xumai 26 was significantly correlated with the post-anthesis nitrogen assimilation, However the grain protein content of Huaimai 18 was significantly correlated with the transfer of reserved (nitrogen) in vegetative organs. The results indicated that different (nitrogen) topdressing time should be adopted in promoting the grain protein content for different specialty wheat (cultivars).