Grain Protein Concentration of WheatT. aestivum L.)-Can cultivation techniques control the grain protein concentration of wheat?

Abstract

The aim of this review is to discuss the possibility of controlling the grain protein concentration (GPC) of wheat, an important factor of wheat grain quality, by cultivation techniques. The GPC of wheat is important to the wheat processing industry and to the wheat farmers. Nitrogen fertilizer is used to control GPC, but this is not easy, because GPC is altered not only by grain protein content but also by grain weight. We reviewed previous papers on the interaction between the timing of nitrogen fertilizer application and GPC or grain yield and found that the application of nitrogen fertilizer at the sowing or jointing stage, when the sink capacity is not determined, is the main factor for increasing the grain yield. Nitrogen fertilizer application after the booting stage, when the sink capacity is almost determined, is the main factor for increasing the GPC. Moreover, the grain nitrogen content is mainly controlled by the source. It may be important to clarify how the application of nitrogen fertilizer affects GPC and grain yield to develop a GPC prediction system that can be used on farmers’ fields.