1. The life of rice goes through two stages: vegetative growth and reproductive growth, and the shortest growth period of rice is three to four months. Among them, the vegetative growth period mainly includes seedling stage and tillering stage. Seedling stage refers to the period from seed germination to seedling drawing; Tillering stage refers to the period from transplanting to turning green to jointing.

2. After transplanting, the root system of the seedling is damaged, and it takes 5-7 days for the overground part to resume growth, and the root system germinates new roots. This period is called the green transition period.

3. Leaf functional period refers to the length of time that leaves keep photosynthetic capacity. With the increase of leaf position, the functional period of leaves changed from short to long, rice 1-3 leaves only lasted for more than 10 days, while the functional period of flag leaves could reach 50-60 days.

4. The main growth characteristics of rice in vegetative growth period are root growth, tillering and leaf increase, and the establishment of certain vegetative organs provides reliable material guarantee for the growth and development of panicle in the future. At this stage, the high-yield seedling frame is mainly built through fertilizer and water management, which requires high quality of the population and should prevent the nutrition from growing too fast. Otherwise, it is not only easy to cause pests and diseases, but also easy to cause difficulties in later growth control, which has a great impact on the formation of rice yield.

5. More than 50% of the grain contents in the middle ear of rice are sticky, and there is no emulsifying phenomenon. The ears in rice feel hard when pressed by hand for 7-9 days. ? Yellow maturity stage: based on 80% yellowing of rice glume, the grain becomes hard and not easy to break. This period is suitable for harvest.

About rice:

1. Rice likes high temperature, high humidity and short sunshine, and has low requirements for soil, and paddy soil is the best. The lowest temperature of seedling germination is 10 ~ 12℃, and the optimum temperature is 28 ~ 32℃. The average daily temperature at tillering stage is above 20℃, and the optimum temperature for ear differentiation is around 30℃. Low temperature prolonged the differentiation of branches and glumes.

2. The optimum heading temperature is 25 ~ 35℃. The optimum flowering temperature is about 30℃, lower than 20℃ or higher than 40℃, which seriously affects fertilization. It takes about 500 ~ 800 kg of water to form 1 kg of rice.

(Reference: Baidu Encyclopedia: Rice)