Abstract
In order to establish the nitrogen topdressing technology with reduced labor for improvement of bread quality, we examined the effects of nitrogen topdressing before and after heading, and also the effect of foliar spraying of urea on dough characteristics using the bread wheat cultivar Minaminokaori from Northern Kyushu. Topdressing of ammonium sulfate at the flag-leaf emergence stage tended to decrease the wet gluten content and valorimeter value, thus deteriorating the dough characteristics more severely than the topdressing at 10 days after heading. The topdressing at 25 days after heading tended to decrease the grain protein content, wet gluten content and valorimeter value, thereby deteriorating the dough characteristics compared with that at 10 days after heading. Foliage spraying of urea caused severer leaf burn than the topdressing of ammonium sulfate. In the once urea sprayed plot, gluten index tended to be lower and valorimeter value was lower resulting in inferior dough characteristics compared with the twice sprayed plot. This is probably because the concentration of urea was higher in the once sprayed plot than in the twice sprayed plot, resulting in incomplete gluten protein synthesis and therefore inferior quality of gluten in the once spraying.
