Field Management of Rice at heading and fruiting stage

The heading and fruiting stage of rice refers to the period from heading to grain maturity. It takes about 25 days for early-maturing varieties, 30-35 days for middle-maturing varieties and 40-45 days for late-maturing varieties. Growth characteristics and appearance at heading and fruiting stage:

1. Fertility characteristics

During this period, the leaf growth stopped, all parts of the spikelet developed, the stem elongation reached the highest height after heading, and the growth center changed from panicle differentiation to rice grain growth. The physiological metabolism was dominated by carbon metabolism, and the accumulated dry matter of grain 2paw 3 was the photosynthate of green leaves after anthesis. This period is the key period to determine the number and weight of filled grains. The main direction of field management is panicle protection, grain attack and weight gain.

2. Index of growth and appearance

The appearance of high-yield rice in the later stage is to maintain a suitable leaf area index and the corresponding number of green leaves per stem. It is required that the number of green leaves can be maintained within 20 days after flowering, each effective tiller can still maintain 3-4 green leaves and the leaf area index is 4-5. At the full ripening stage, 2 pieces of japonica rice and 1 piece of flag leaf and second leaf of indica rice were required to be kept yellow, and the leaf area index was about 2 until maturity.

The heading and fruiting stage of rice is the last stage of forming yield, improving quality and maintaining long-term quality in autumn, from full heading to harvest. During this period, the central task should focus on foliar fertilization, intermittent irrigation, prevention and control of rice locusts, and keeping the living stalk mature. The specific measures and operations are as follows:

① spraying foliar fertilizer

The purpose of spraying foliar fertilizer is strong seeds to improve maturity and plumpness. From the point of view of improving quality, it is not suitable to spread urea and other long-acting nitrogen fertilizer again, but it is better to spray leaves on fields with yellow leaves after heading, generally spraying 2.5 kg of potassium dihydrogen phosphate and 5 kg of urea per hectare, 400 kg of water, and spraying at flowering stage. Or the combination of biological potassium, Jinmanli, Huimanfeng and plant growth regulators can not only increase the yield of strong seeds, but also prolong the root activity, keep the living stem mature, prevent lodging and improve the quality.

When the leaf color turns yellow 10 days after heading, and the degree of yellowing is more serious than that of "falling yellow at booting stage", grain fertilizer is used. At this time, if no grain fertilizer is applied, the plant will lose its vitality, which will accelerate the decomposition of chlorophyll and decrease the maturity, resulting in a decrease in yield. The amount of grain fertilizer is generally 3 kilograms of ammonium sulfate per mu. Shallow water should be irrigated in the field when fertilizing, and no irrigation should be done after fertilization, so as to let it dry naturally.

Look at the seedling topdressing. After rice heading and flowering, maintaining the appropriate nitrogen content of rice plant is very beneficial to improve the photosynthetic efficiency of leaves and prolong the functional period of leaves. In the fields where panicle fertilizer is insufficient or no panicle fertilizer is applied in the middle stage, nitrogen grain fertilizer should be applied in the early stage of heading, and combined with phosphorus and potassium fertilizer. Spread 1.5-2.5 kg of urea per mu; foliar fertilization 100-250 g / mu of potassium dihydrogen phosphate, or 0.5-1.0 kg of urea, first dissolved in 20-30 kg of water, soaked for 24 hours, then filtered out the residue, and then sprayed with 50 kg of water. Foliar fertilization can not only solve the problem of weak fertilizer absorption of rice roots in the late growth stage, but also has high and fast fertilizer efficiency.

Foliar fertilization should be carried out in the evening or at 3-4 p. M. on a sunny day, so that the fertilizer adheres to the leaf for a long time and is thoroughly absorbed. On cloudy days, it can be sprayed all day. Rice flowering stage, should avoid 9-12:00 in the morning, so as not to affect flowering and pollination.

② intermittent irrigation

When rice heading and flowering enters the filling stage, intermittent irrigation is adopted, that is, it is irrigated once and so on after it dries up, and the front water does not see the back water. The current tide seeps down, and the tide after reirrigation can increase the air permeability of the soil, make the root, protect the leaf with the root, protect the yield with the leaf, make the rice root deep and luxuriant, ensure that the rice has three functional leaves in the later growth stage, green branches and green leaves do not senescence prematurely, improve leaf photosynthesis, increase seed dry matter accumulation, accelerate filling speed, promote seed maturity, improve maturity, increase 1000-grain weight, and achieve high yield.

After heading, the leaf transpiration decreased, and the effect of water temperature on rice in the later growth stage was less than that of air temperature. The basic principles of water management of rice from heading to maturity are as follows: intermittent irrigation is adopted 20 days after heading to keep the soil saturated, that is, flowers reach water, with a water depth of 3-5 cm each time; when heading for 20-35 days, "horse race water" measures are adopted to maintain 80% of the maximum capacity. After that, the time of stopping irrigation and falling into the water was decided according to the mature situation. The clayey soil or depression with poor drainage should stop irrigating the sun-dried field about 25 days after heading, the leaking field should prolong the irrigation time properly, the groundwater level is low, and the paddy field with good drainage should stop irrigation and sun-drying field about 35 days after heading. It is necessary to prevent lodging or reduction of green leaf area caused by premature lack of water in the soil.

③ timely control of diseases and insect pests

After heading, rice will also have leaf blight, sheath blight, rice neck ear disease, rice planthopper, armyworm and other diseases, should be checked frequently, once the disease and insect damage is found, timely control.

Rice flax spot, red blight and rice blast should be prevented at an early stage. Apply 800 times liquid of double-effect micro-fertilizer to spray evenly, and re-spray in circuitous rain within 6 hours after spraying. It has a good effect on the prevention and control of the above diseases, and can increase the yield of rice by about 15%. In this period, rice locusts on the edge of the field should be controlled in time to ensure that the functional leaves will not be damaged, so as to achieve the purpose of increasing production, income and quality.

Elimination of weeds in later stage by ④

Timely control of weeds such as floating duckweed and moss, and removal of weeds in fields, ridges, canals and fields, so as not to block light and affect the rise of water temperature, but also reduce the shortage of grass in the next year and reduce the source of infection of diseases and insect pests.

⑤ lodging prevention

The main reasons for lodging in production are as follows: first, improper fertilization, excessive application of nitrogen fertilizer, excessive growth of big head fertilizer in the early stage, starvation and premature senescence in the later stage, withering of stems and leaves, irrigated irrigation, damage of diseases and insect pests and the influence of wind and rain. The radical cure of lodging seedlings should improve the level of cultivation and management in all aspects, such as changing unscientific fertilization and selecting excellent varieties, sparse sowing and sparse planting, frequent irrigation in shallow water, timely drying and so on.