Effects of nitrogen top dressing time on yield and quality in wheat with different types of grain color

This study was conducted to investigate the effects of nitrogen top dressing time on yield and quality in wheat with different types of grain color. The cultivars were white wheat (Jindong8 and Wanmai38), black wheat (Luozhen1 and KZ6061), and green wheat (Lvmai1 and Lvmai2), Black wheat and green wheat had pigment in endosperm and seed coat. The results showed that, comparing to nitrogen applied at the 2 leaf stage, nitrogen applied on the 5 leaf stage resulted in higher protein content. The protein content was significantly higher in color wheat than in common white wheat. Nitrogen application at late stages of wheat growth could magnify the differences of the protein content between colored wheat and common white wheat. Nitrogen applied at late stages enhanced protein contents in wheat with black and green colored grain. No difference was found on the effects of nitrogen top dressing time on the processing quality between different varieties. Nitrogen applied on the 5 leaf stage resulted in better processing quality than on the 2 leaf stage. The differences of development and stability time resulted from N applied time between two treatments were not significant. Sedimentation volume and gluten content were higher in color wheat than in white wheat. Processing quality in black wheat was better than that in green wheat. Consequently, nitrogen applied strategies were rather more important to improve processing quality of black wheat. Grain yield in color wheat was lower than that in white wheat, but higher than green wheat. Yield in green and white wheat showed a relative larger response in green and white color wheat than black one.