1. Rice ripening is divided into four stages: milk ripening stage, wax ripening stage, complete ripening stage and dry ripening stage. Milk maturity is the time when rice begins to fill 3-5 days after flowering. The duration is about 7- 10 days. At the end of milk ripening, the fresh weight reaches the maximum. During this period, the grain in the middle of the rice ear feels hard by hand. Wax ripening period lasts about 7-9 days. During this period, the grain contents of rice were sticky, no milk appeared, and the dry weight was close to the maximum. The green color on the back of the rice grain began to disappear gradually, and the chaff turned yellow. In the mature stage, the rice husk turns yellow, the water content of rice grains decreases, the dry matter weight reaches a fixed value, and the rice grains become hard and not easy to break. This period is the best harvest period. About 45-50 days after heading, the yellowing rate of rice reached over 95%. ?

In the stage of drying and ripening, the husk yellow of rice gradually becomes pale, the branch japonica becomes dry, the top branch japonica is easy to break, and the rice grain occasionally has traces of cross section, which will affect the rice quality.

Second, different places, different stubbles and different varieties have different harvesting times.

1, two crops a year, and the harvest time is June of the lunar calendar and 10. Once a year, about September.

After the National Day, it is the time for rice harvest. However, due to the continuous rainfall in recent days, it was rainy and snowy yesterday, which affected the rice harvest in Panjin City. This year, due to the low temperature in the early stage of rice and insufficient rice growth, rice generally ripens later than in previous years.

3. There are three seasons of rice in southern Anhui, and early rice will be harvested in late July. Mid-season rice: harvested from late September to early October/kloc-0.