Effect of Nitrogen Application on Yield,Rice Quality and Processing Characteristics in Rice Noodle-specific Varieties

【Objective】We aimed to investigate the influence of nitrogen application on yield, rice quality and processing characteristics in noodle-specific rice.【Method】The experiments were conducted with three rice varieties suitable for making rice noodles(R0734, R2149, Jiazao 66), one variety commonly used for making rice noodles(Zhenguiai) and one variety unable to be processed into rice noodles(R0711) at three nitrogen levels with 90, 140, 190 kg/hm2 in 2018 and 2019.【Result】1) With the increasing nitrogen application levels, the yield of each varieties increased, but for R0734 and R2149 the grain yield maximized under the medium nitrogen level of 140 kg/hm2 in 2019; noodle-specific rice varieties, R2149 and Jiazao 66, had extremely high yield advantages, achieving the highest yield at the nitrogen levels of 140 kg/hm2 and 190 kg/hm2. Nitrogen application increased the effective panicle number, while the 1000-grain weight decreased. 2) As more nitrogen was gradually applied, gel consistency and protein content increased while amylose content decreased, fluctuating between 21.4% and 26.5%, which also brought about a downward trend in peak viscosity, trough viscosity and final viscosity. Breakdown reduced significantly and setback increased significantly. 3) With the increase of nitrogen application, the broken rate and cooked loss rate of rice noodle increased significantly, but both were below 10%. R2149 and Jiazao 66 were more sensitive to nitrogen levels than R0734, but had better processing properties.【Conclusion】The amylose contents ranging from 21% to 27%(about 24% is the best) are favorable, so that the amylose content will not seriously exceeded the suitable range for processing at different nitrogen application levels in field cultivation. Moreover, due to the increase in the amount of nitrogen application, the processing characteristics of noodle-specific rice are deteriorated. Thus it is necessary to apply relatively low nitrogen in condition of its high yield level. In the breeding, the major parents with moderate amylose contents and better processing characteristics should be selected for high-yielding noodle-specific rice variety.