On the Temporary Storage of High Moisture Rough Rice : III. Effect of harvesting by the combine on the quality of rough rice grain during storage

[摘要] In the present investigation, the authors observed the changes caused during the storage in the quality of rough rice grains harvested by the combine harvester (cylinder speed, 1, 100-1, 700 m/min). For this purpose, sample rough rice were harvested by the combine on September 7 and November 8, 1966, and were conditioned at five moistur-content levels, approximately at 16, 18, 20, 22, and 24%, and stored for 30 days at temperature of 23°C, 28°C, 32°C and variable (in a barn of wooden construction, room temperature 25.8°C to 17.6°C) in case of samples harvested on Sept. 7; and 13°C, 18°C, 23°C and variable (room temperature 15.2°C to 7.5°C) in case of samples harvested on Nov. 8. The results are summarized as follows: 1. In the case of samples containing less than 20% moisture, any appreciably great changes in moisture content were not noticed during the storage period, irrespective of the different harvesting dates, while in the samples containing more than 20% moisture, moisture content increase at the latter storage stage when stored at tempratures of 23°C, to 32°C. 2. The occurence of deteriorated grains in the course of storage for 30 days was on the upward trend accordiny as the moisture-content and storage temperature became higher, and when stored at variable temperature in a barn of wooden construction, the grains harvested on earlier date tended to become more liable to be deteriorated. In the case of grains of moisture-content of less than 18%, little or no deteriorated grains were noticed during the 30 days storage at the respective temperatures ranging from 13°C to 32°C, irrespective of different harvesting dates In the course of storage for 30 days, the rough rice grains heavested by the combine were more often deteriorated than the grains threshed using the self-feeding thresher. 3. Viabilty of embryos (TZ values) both of the grains harvested on earlier date and on later date tended to decrease more rapidly at the latter storages according as the moisture-content and the storage temperature became higher. 4. In case where 23.6% moisture-content grains harvested on Sept. 7 were stored at temperatures of 23°C to 32°C and variable, grains could safely be stored only for one day, while in case where grains containing 18% moisture heavested on Sept. 7 or grains of less than 18.9% moisture heavested on Nov. 8 were stored at temperatures of 13°C to 23°C and variable, both grains could safely be stored for 30 days without any deterioration in their quality. In case of the grains of the same moisture-content, the maximum safe storage duration of the rough rice harvested by the combine was shorter than that of the grains threshed by the selffeeding thresher. This was thought chiefly due to the fact that the percentage of the injured grains harvested with combine was higher than that threshed by the self-feeding thresher.

[学科分类] 农业科学（综合）