Screening Suitable Harvest Time for High-Quality Rice
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.