Abstract:

Timely harvesting is a technical measure to achieve synergistic improvement of yield and quality of high-quality rice. The yield and quality indicators of different harvest treatments [T1, harvested at 80% maturity (yellow ripening rate of grains); T2, harvested at 90% maturity; T3, harvested at 100% maturity; T4, harvested at 5 days after 100% maturity; T5, harvested at 10 days after 100% maturity] were studied with 6 high-quality rice varieties under field conditions. The results showed that the yield of the tested varieties showed an upward trend with the increase of maturity, and reached its highest at 10 days after 100% maturity harvesting. When maturity reached 100%, the rate of head milled rice tended to remain stable. There was not much variation in the rate and degree of chalkiness between different treatments. Harvested at 90% to 100% maturity, the tested varieties exhibited moderate disintegration values and attenuation, with relatively good taste quality. Harvested at 100% maturity, the free fatty acid content in brown rice of most of the tested varieties was stable and reached relatively low level. The highest content of aroma compounds were found in three fragrant rice varieties harvested at 90% to 100% maturity. A comprehensive evaluation of the suitable harvest period for high-quality rice was conducted by yield, whole head rice rate, free fatty acid content, disintegration value, and reduction value. The results showed that the optimal harvest period for high-quality rice was at 100% maturity. If considering the differences between varieties, high-quality rice was suitable to be harvested at 90% to 100% maturity in the actual production process.

Key words: high quality rice, harvest time, yield, grain quality

摘要：

适期收获是实现优质稻产量和品质协同提高的一个技术措施。以6个优质稻品种为材料，在田间条件下，测定不同时期收获处理[成熟度（籽粒黄熟率）达到80%时收获、成熟度达到90%时收获、成熟度100%时收获、成熟度100%后5 d收获、成熟度100%后10 d收获]的水稻产量和品质指标。结果表明，参试品种产量均随着成熟度的增加呈上升趋势，在成熟度100%后10 d收获的最高。参试品种的整精米率在成熟度达100%时趋向稳定；垩白粒率和垩白度不同收获期处理间变化不大；在成熟度为90%~100%时收获，参试品种表现出适中的崩解值和消减值，食味品质相对较好；大部分品种在成熟度100%时收获糙米游离脂肪酸含量稳定，且为较低水平；3个香稻品种在成熟度90%~100%时收获，其香味物质含量最高。选择产量、整精米率、游离脂肪酸含量、崩解值和消减值等5个参数对优质稻的适宜收获期进行综合评价结果认为，优质稻成熟度（籽粒黄熟率）100%时为其适宜收获期，考虑到品种间差异，在实际生产过程中优质稻适宜在成熟度90%~100%时收获。

关键词: 优质稻, 收获期, 产量, 稻米品质