First, winter wheat flowering management
The growth rate of wheat began to accelerate after heading, and some flowers would bloom after 2~5 days. At this time, wheat has also entered the flowering period. The flowering period of wheat is a sign of further transformation from vegetative growth to reproductive growth, and it is also a key period to determine the number of grains per spike.
1, reproductive characteristics
Wheat flowering can last for 6~7 days, and flowering is related to temperature. The lowest temperature for flowering is 9℃, the highest temperature is 30℃, and the suitable temperature for flowering is 20℃. Wheat flowering is also related to air relative humidity, and the most suitable air relative humidity for flowering is 70%~80%. If the air relative humidity is lower than 20%, it will be unstable; However, if the relative humidity of the air is too high and it rains continuously during flowering, pollen grains will absorb water, swell and rupture, lose their fertilization ability and fail to bear fruit.
2. Management measures
Knowing the growth characteristics of winter wheat at flowering stage, let's take a look at what management should be done during this period.
(1) Water and fertilizer management
Flowering stage is the most vigorous stage of winter wheat plant metabolism, which requires a lot of energy and nutrients, and should be combined with watering and topdressing once. In this period, nitrogen fertilizer should be the main fertilizer, because nitrogen is the main component of synthesizing protein and chlorophyll. In addition to regulating physiological functions, it also plays a significant role in increasing the green leaf area of wheat. Because 70%~80% of wheat grain yield comes from the accumulation of photosynthetic products in the later stage, the increase of leaf area enhances photosynthesis and nutrient accumulation. Therefore, in the flowering period of winter wheat, applying appropriate amount of nitrogen fertilizer is helpful to improve wheat yield. It is suggested that soil nitrogen deficiency should be detected by soil testing, and then nitrogen fertilizer should be applied as needed.
Wheat needs more water at heading and flowering stage, and the water consumption accounts for 40% of the total water consumption in the whole growth period. Therefore, it is necessary to combine fertilization and water once. Flower water? Water it thoroughly this time. Often encountered during this period? Dry hot wind? Weather, when the temperature is higher than 30℃, it will affect the fertilization ability of winter wheat and reduce the fruiting. Then, water it? Flower water? It can not only increase the relative humidity of soil and air, but also cool the wheat field.
(2) timely control of pests and diseases
The flowering period of wheat is also a period of high incidence of pests and diseases. The main pests to be controlled at this stage are wheat midge, wheat spider and wheat aphid. The diseases that need to be controlled include wheat stripe rust, wheat powdery mildew, wheat leaf blight and wheat scab.
Once pests and diseases are found in wheat flowering period, comprehensive control should be done. We should vigorously promote biological, physical and ecological prevention and control technologies. From the end of April to the beginning of May, spray with 4.5% beta-cypermethrin EC 1000~ 1500 times, 10% imidacloprid wettable powder 1000 times or 2.5% beta-cypermethrin EC 2000~3000 times. In case of cloudy weather in flowering period, pay attention to using 40% carbendazim gel suspension100g and watering 50 kg per mu to prevent scab. Can foliage be sprayed with fertilizer to resist? Dry hot wind? And play a role of multiple prevention with one spray.
Second, the management of winter wheat filling period
The flowering stage is followed by the filling stage, which is the key period to determine the wheat yield.
1, reproductive characteristics
It takes 30~40 days for wheat to bloom, fertilize and mature. Since fertilization, it has entered the stage of grain formation, and it takes 10~ 12 days. When the grain length reaches three-quarters of the maximum length, it is called the most grain, which marks the end of the grain formation stage. After grain formation, the filling stage is from most grains to the top Man Cang, and then to the end of milk ripening.
During this period, starch accumulated rapidly in the endosperm, and the dry matter increased sharply. The filling period generally took 12~ 19 days. When the temperature is too low, the milk ripening period will be obviously prolonged, the seeds in the early stage of milk ripening will turn green, the endosperm will be filled with white milky juice, and the juice concentration will become thicker with the panicle filling. The temperature at milk maturity has a great influence on the grain filling speed. The optimum temperature is 20~22℃. When the temperature is higher than 25℃, transpiration is accelerated, the filling time is shortened, the dry matter accumulation process is completed ahead of schedule, and the yield is reduced.
In addition, high temperature will increase the respiration of plants and grains and consume too much organic matter. Therefore, high temperature and dry climate should be prevented during grouting, especially? Dry hot wind? Invasion. In a hot and dry climate or? Dry hot wind? Watering should be implemented before arrival to reduce the ground temperature and improve the microclimate in the field.
2. Water and fertilizer management During the milk ripening period of wheat, the maturity of grain is closely related to the relative soil water content, and the most suitable soil water content for grain filling should be 70%~80% of the maximum field water capacity. If the soil is short of water, it will lead to premature senescence of leaves, weakening of photosynthetic intensity, limiting the transportation of photosynthetic products to grains, stopping the filling process, causing the grains to shrink, reducing the 1000-grain weight and affecting the yield.
According to the growth characteristics of winter wheat at grain filling stage, proper soil moisture should be maintained in production, and fertilizer should be sprayed on the leaves to supplement the nutrition of wheat plants; It is also necessary to eliminate the accumulated water in the field in time, ensure the root activity, extend the functional period of leaves and prevent premature aging. So as to achieve full grain and increase grain weight.
Maintaining suitable soil moisture is very beneficial to grain filling. It is best to keep the wheat field moist and dry, and water it ten days after flowering and twenty days after flowering respectively. Good grouting water irrigation can not only alleviate the drought in wheat field, but also regulate the microclimate in the field and prevent it. Dry hot wind? Influence of weather on grouting. Moreover, irrigation can also prolong the function of leaves, prevent premature senescence of plants, and be conducive to further improvement of wheat yield. Therefore, farmers' friends should master the following points when pouring slurry:
First, plots with high soil fertility and good water content can be watered without slurry; Second, the population is too large and the growth is too prosperous. Try not to water the plots with lodging risk. Otherwise, once lodging happens, the production will be reduced more and the risk will be greater; Third, listen to the weather forecast before watering, and water is forbidden before heavy rain to prevent lodging; Fourth, when watering during grouting, a small amount of water should be used frequently.
Because of too much soil moisture in the late filling stage, more organic matter will stay in the stem and the yield will decrease. Therefore, there is no need to water again in the later stage of grouting. When wheat grows to the late filling stage, individuals decline, physiological activities weaken and the ability to absorb nutrients decreases. At this time, the leaves began to turn from green to yellow, the photosynthetic capacity decreased, the photosynthetic products produced were also reduced, and the plants appeared premature aging, which seriously affected the grain filling degree.
In order to reduce the effect of premature aging on grain filling, foliar fertilizer can be sprayed to supplement nutrition for wheat plants. 200 grams of potassium dihydrogen phosphate, 500 grams of urea and 50 kilograms of water are used for foliar spraying per mu. Potassium dihydrogen phosphate can also promote the synthesis of cellulose and lignin, improve the stem strength and reduce the risk of lodging in the late growth stage of wheat. Foliar spraying should be carried out before 9 am or after 4 pm on sunny days. Spray as evenly as possible to keep the leaves moist and not dripping.
Water accumulation during wheat filling period, especially in the late filling period, will cause diseases such as rotten roots and dead leaves, and accelerate premature aging. After the heavy rain, there may be some water in the wheat field. At this time, it is necessary to ditch and drain water in time, resolutely eliminate open water, reduce self-injury, protect roots and leaves, promote wheat grain maturity and improve grain weight. Timely drainage can also prevent soil water from supersaturation and lead to wheat lodging.
Third, the management of winter wheat maturity.
After the critical period, it is the maturity of wheat and the last growth period in wheat production. After wheat enters the grain maturity stage, the biggest feature is that the accumulation of dry matter slows down, the moisture in the grain drops rapidly, and the grain volume begins to shrink.
The process of grain ripening includes two stages:
Wax ripening period: also called yellow ripening period. The plants entering this stage turn from green to yellow, and the seeds gradually harden. The substances contained in seeds are as plastic as wax, which can be crushed by hand and twisted into strips. Then it hardened and should not be crushed. At this stage, soluble substances in different parts of the plant are still accumulated in the grain, but the quantity is far less than that in the previous stage. Therefore, although the dry matter continues to increase, the speed is slow, and the wax ripening period generally takes 6~ 15 days. Complete maturity stage: when dry matter stops accumulating, the grain volume shrinks, and the grain becomes hard and cannot be cut off by hand, it enters the complete maturity stage. The maturity time is very short, usually only 3~5 days. Harvest time is also related to the yield and quality of wheat, and wheat harvest too early or too late will reduce production. Early harvest, poor grain maturity and low grain weight, and at the same time, due to the high water content of stems and grains, it is not only difficult to thresh, but also easy to get hot and moldy when drying; When the harvest is too late, the dry matter will not increase, but the stem respiration is still very strong and it is easy to consume nutrients. Moreover, once the maturity period is over, all the plants will wither and naturally drop seeds, which will also reduce the yield of wheat. Therefore, it is best to harvest wheat before the end of wax maturity, and not later than full maturity at the latest.
When harvesting wheat, besides the maturity of wheat grains, weather is also one of the factors to be considered. If it doesn't rain in the near future, you can harvest at the time mentioned above. If it rains at the end of wax ripening and the end of wax ripening, it should be harvested before it rains to prevent wheat grains from sprouting on the wheat ears and bringing losses to production. The farmer said? Nine ripe, 100% harvest; Ten mature, ten lost? That's the truth.
Although the management of winter wheat is relatively simple, we must pay attention to the management of several key periods, especially the flowering and filling period, which is the most critical period for winter wheat to finally obtain high yield. Therefore, farmers should take it seriously in order to achieve the final high yield!