Effects of a Higher Top to Basal Nitrogen Dressing Ratio on the Yield and Quantity of Waxy Barley in Niigata Prefecture

Abstract

Glassy grains in barley tend to increase with nitrogen topdressing at a later growth stage. A characteristic of waxy barley varieties is that their glassy grain rate is less likely to be increased by topdressing. The yields of these varieties is expected to be raised by using a higher top to basal nitrogen dressing ratio or high nitrogen topdressing while maintaining a low glassy grain rate. We cultured the waxy barley variety ‘Haneumamochi’ and its non-waxy original version ‘Fiber Snow’ in Niigata Prefecture using a higher top to basal nitrogen dressing ratio and compared their yield and quality. We tested three types of dressings: ‘normal topdressing,’ which has a higher rate of basal to topdressed nitrogen, ‘high topdressing ratio,’ which has reduced basal nitrogen and higher topdressed nitrogen, and ‘increased topdressing,’ which has a higher topdressed nitrogen ratio than ‘high topdressing ratio.’ The yield from ‘high topdressing ratio’ was higher than for ‘normal topdressing.’ It appears that in the ‘high topdressing ratio’ plants, the number of spikelets increased as a result of higher nitrogen concentration in the plants in winter, which is the early spikelet differentiation period. The number of grains per head also increased as a result of a decrease in sterility of the lower spikelets due to topdressing during the flag leaf emergence stage. The glassy grain rate of ‘Haneumamochi’ was clearly lower than that of ‘Fiber Snow.’