2019 Volume 88 Issue 2 Pages 98-107
“Setokirara”, a wheat cultivar for bread in western Japan, has high yield potential, although its grain protein content (GPC) could be lowered when the yield level was high. The objective of this study was to examine the effects of intensive nitrogen fertilization during stem elongation (INFSE) for achieving both high yield and high GPC in “Setokirara”. The effects of increased nitrogen at an early stage and/or increased total nitrogen in wheat obtained by INFSE were also examined. In 2015/16 and 2016/17, grain yield in the INFSE group was 11-40% higher than that of the conventional fertilized wheat (control) with a 16-23% increase in spike number per unit area. GPC in the INFSE group did not decrease despite the increase in yield. Thousand grain weight in the INFSE group was 2.3 g heavier than that in the control group in 2016/17 when precipitation was moderate and hours of sunlight was sufficient during grain filling. The increase of nitrogen applied at an early stage and increase of total nitrogen had a small effect on the yield of wheat given INFSE. Nitrogen accumulated in the aboveground organs at maturity was around 12-16 g m–2 across treatments even though total nitrogen applied ranged from 16 to 30 g m–2. INFSE increased the yield without decreasing GPC in “Setokirara”. Therefore, INFSE would be useful for cultivating high-yield wheat cultivar for bread.
