How to do the field management in the later stage of winter wheat in 2020? Shanxi Ministry of Rural Agriculture gives guidance!

Grain Rain has passed, and winter wheat has entered the heading and flowering stage from south to north. This stage is the key period for the formation of wheat yield. So, how to do the field management in the later stage of winter wheat in 2020? Shanxi Ministry of Rural Agriculture gives guidance!

Recently, news came from the Shanxi Provincial Agricultural and Rural Department that in order to ensure a bumper summer grain harvest this year, the Provincial Agricultural and Rural Office recently issued the "opinions on Field Management of Winter Wheat in the later stage of 2020" to guide the field management of winter wheat in various localities.

Affected by the warm winter, the overall growth period of winter wheat in Shanxi Province is ahead of schedule, and the current seedling situation is generally good, but the occurrence of diseases and insect pests is grim and complicated. therefore, all localities should attach great importance to it. We should conscientiously implement the plan of "fighting for a bumper harvest of summer grain in 100 days" of the Ministry of Agriculture and Village and the "three major agrotechnical actions" of the National Agricultural Technology extension Service Center, always pay attention to weather changes and the trend of occurrence of diseases and insect pests, and be based on disaster prevention and reduction. Focus on "strengthening the regulation and control of water and fertilizer, strictly preventing cold damage and lodging of strong winds, strengthening the prevention and control of diseases, pests and weeds, preventing the harm of dry and hot wind, doing a good job of" one spray and three prevention "in the later stage, strengthening field management, and winning a bumper wheat harvest.

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Opinions on Field Management of Winter Wheat in the later stage of 2020

At present, winter wheat in Shanxi Province has entered the heading and flowering stage from south to north. Judging from the recent survey, the growth period of wheat in Shanxi Province is generally 7-10 days ahead of schedule this year. Due to the influence of sufficient Rain Water in winter and spring and high temperature, the paddy wheat fields in the south that were sown late due to frequent rainfall during the sowing period have obviously upgraded, dryland wheat is growing well because there is no obvious drought, and the growing momentum of prosperous wheat fields in some dryland before winter has been effectively controlled due to the lack of Rain Water in March and repeated cooling and growth from the end of March to mid-April. The current seedling situation is a good year in recent years, but there are still some risk factors in the later stage. first, the diseases and insect pests occur seriously in spring, and the situation is grim and complicated, especially in the counties (cities) along the Yellow River. Plant protection experts predict that the main diseases and insect pests of winter wheat in Shanxi Province in the middle and later period will be more serious than last year and perennial years, and scab will occur moderately. Second, two consecutive frost weather occurred from the end of March to the middle of April. at present, there are no obvious symptoms of frost injury, but the lagging effect of frost injury can not be ignored. In the later stage, natural disasters such as low temperature and cold injury, dry and hot wind, strong wind and hail still need to be paid great attention to; third, there is still a certain proportion of late sowing weak seedlings and prosperous seedlings, and field management still needs to be paid great attention to.

In view of the current good situation of wheat seedlings, but the severe situation of diseases and insect pests and the uncertain situation of meteorological disasters, the guiding ideology of field management of winter wheat in the later period of this year is based on disaster prevention and reduction, with the goal of protecting grain number and grain weight. Prevention of diseases and insect pests, prevention of low temperature and cold damage, prevention of dry and hot wind, prevention of lodging and prevention of premature senescence as the focus of field management, reasonable regulation and control of water and fertilizer, timely prevention and control of diseases, pests and weeds, scientific management Seize this year's good wheat harvest.

I. strengthening the regulation and control of water and fertilizer

In the later stage of wheat growth and development, water and fertilizer supplement and prevention of premature senility should be regarded as the focus of water and fertilizer management, classified management, so as to promote the high yield of large spike and multi-grain.

(1) to prevent drought and replenish water due to soil moisture. From heading to mid-filling stage, wheat should be irrigated with heading, flowering and filling water to promote multi-grain weight. From heading to grain formation stage, if the soil moisture is insufficient, it will often lead to grain degeneration and dry shrinkage, and reduce the number of grains per ear and grain weight. Therefore, it is necessary to water enough heading and flowering water in time to meet the water demand of photosynthate synthesis and transportation and rapid grain expansion. After entering the filling stage, maintaining a suitable soil water supply is an important measure to prolong the leaf photosynthetic function period, prevent premature senescence and increase grain weight. Therefore, when the relative water content of the soil is less than 60%, the grouting water should be poured in time if there are irrigation conditions. It should be noted that unreasonable watering during filling period often leads to late ripening and lodging. Four principles should be followed in watering slurry water: first, less frequent watering, and each time the amount of water should not be too large; second, watering in wind and rainy weather is strictly prohibited; third, watering should be stopped half a month before maturity; fourth, irrigation should be strictly controlled in wheat fields that apply too much nitrogen fertilizer.

(2) foliar fertilizer spraying to prevent premature senility. Heading to filling stage is not only the most important period for the formation of wheat yield, but also the key period to prevent premature senescence and increase grain weight. Spraying potassium dihydrogen phosphate twice on wheat leaves from heading to filling stage can make up for the deficiency of root absorption of nutrients, effectively increase phosphorus and potassium in plants, enhance wheat stress resistance, prolong leaf functional period, improve wheat physiological activity, speed up grain filling, promote good yellowing and early ripening of wheat, prevent and reduce the harm of dry and hot wind and wilt, increase the number of grains per spike, and stabilize 1000-grain weight. So as to increase the yield and improve the quality. Therefore, regardless of paddy land and dry land, potassium dihydrogen phosphate can be sprayed from heading to the middle of grain filling, with a general dosage of 200 grams per mu and 40-50 kg of water. Strong gluten wheat, yellow wheat field, frozen wheat field and hailstorm wheat field can be sprayed with urea 1 kg and potassium dihydrogen phosphate 100 g per mu, water 40 kg 50 kg, foliar spraying 2 times, and the spraying interval is about 10 days.

Strictly guard against low temperature and cold injury and strong wind lodging

At the end of April and the beginning of May, low temperature chilling injury occurred in Shanxi Province, and wheat would be damaged if the minimum temperature was lower than 5: 6 ℃. Therefore, we should pay close attention to the weather forecast and take measures such as irrigation, spraying anti-frost agent or using intelligent smoke generator to prevent and reduce the occurrence of low temperature cold (freezing) damage. Once occurs, should be timely watering or foliar spraying of potassium dihydrogen phosphate, brassinolide and other foliar fertilizers or plant growth regulators to promote restorative growth.

In case of windy weather, stop irrigation in the field immediately. According to the weather forecast, ditch drainage measures can be taken before the storm to reduce the risk of root lodging and stem lodging due to excessive soil and plant water content. If the wheat loses at a later stage, manual help is strictly prohibited to prevent further damage. After wheat lodging, the stem will generally grow upward from the most vigorous meristem, restore the head and part of the stem to erect, and the photosynthesis and transport function will be partially restored. After lodging, foliar spraying of potassium dihydrogen phosphate can be adopted to enhance its stress resistance. at the same time, attention should be paid to prevent the spread of diseases such as rust and powdery mildew in lodging wheat fields, and foliar fertilizer and fungicides can be sprayed on the leaves to promote growth and control diseases.

Third, strengthen the prevention and control of diseases, pests and weeds

From booting to filling stage, with the rise of temperature, the occurrence of aphids, midges, powdery mildew, rust, scab and other diseases and pests will increase. Under the influence of warm winter, high temperature and high humidity this year, diseases and insect pests occur early and seriously, so all localities should strengthen monitoring and take corresponding control measures for different diseases and caterpillars.

Wheat stripe rust is a serious disease, which occurred locally in the southern part of Shanxi Province in recent years. Stripe rust spread rapidly in winter areas this year, and the source of bacteria was extremely rich. with the rise of temperature and the introduction of non-local bacterial sources, Yanhuang County (city) in Shanxi Province first saw the disease on March 20, one month earlier than usual. For stripe rust, it is necessary to fully implement the prevention and control strategy of "carrying medicine to detect, manage and protect noodles", take preventive measures of "find one point, control one piece", and control the disease center in time when the average rate of diseased leaves in the field reaches 0.5% to 1%. Organize to carry out large-scale emergency prevention and control, and achieve full coverage of prevention and control in similar areas. The medicament can choose triadimefon, diniconazole, tebuconazole, fluconazole, hexazole, propiconazole, ether carbendazim and so on.

In recent years, wheat scab in Shanxi Province has shown a trend of aggravation. We should always pay attention to the weather changes. For the areas where scab may occur (highly susceptible wheat varieties), if the weather forecasts that the flowering period of wheat will have more than 2 days of continuous overcast and rain, the first application time should be advanced to the heading stage, and the insecticides can be used in sufficient quantities, such as cyanenoxim, prochloraz, tebuconazole, thiophanate, methyl thiophanate, Bacillus subtilis, etc. If there is rain within 3-6 hours after application, it should be remedied in time after rain.

Powdery mildew and leaf rust are common diseases of wheat in Shanxi Province. In the early stage of the disease, when the diseased leaf rate of powdery mildew in the field reached 10% or the diseased leaf rate of leaf rust reached 5%, tissue control should be carried out in time, and the agents could be triadimefon, diniconazole, pyrazolyl carbendazim, propiconazole, etc.

Trematodes mainly occur in Laoshui area. In the key areas where trematodes occur, the poisonous soil made of phoxim granules can be evenly sprinkled on the surface before wheat heading, and then watered for control. Phoxim, cyhalothrin, cyhalothrin and imidacloprid can be sprayed before flowering after heading.

The occurrence of wheat spike aphid is common in Shanxi province. When the number of wheat aphids reached 800 and the ratio of benefit to damage (natural enemies: aphids) was less than 1: 150, the insecticides such as imidacloprid, acetamiprid, imidacloprid, aldicarb, matrine and ear mold were sprayed to control aphids. It is recommended to release aphid cocoon wasps and ladybugs for biological control. In the mixed areas of many kinds of diseases and pests, suitable fungicides and insecticides can be used scientifically and applied comprehensively.

For the wheat fields with severe grass damage in the later stage, the weeds should be pulled out manually before the weeds bear fruit, so as to reduce the amount of grass seeds left in the fields and prevent them from spreading into disasters. Because grass seeds tend to mature earlier than wheat, and the reproduction coefficient is high, especially Gramineae weeds. At the same time, attention should be paid to the control of weeds in the field to prevent grass seeds from being brought into the field due to watering and farming.

Fourth, prevent the harm of dry and hot wind

From wheat filling to maturity, Shanxi Province is often damaged by dry and hot wind, resulting in early ripening or wilting of wheat and a serious decrease in grain weight. Therefore, active preventive measures can be taken in areas with frequent occurrence of dry and hot wind. First, the grouting water should be poured at the right time. Generally, watering during the milk-wax ripening period and before the perennial dry-hot wind frequent period can effectively reduce the microclimate temperature in the wheat field, increase the humidity, reduce the transpiration water consumption intensity of the plant, and effectively reduce the harm; second, spraying 0.2-0.4% potassium dihydrogen phosphate solution 2 times from booting to filling stage to increase the content of phosphorus and potassium in the plant and improve the stress resistance of wheat. Third, from booting to filling stage, wheat can be foliar sprayed twice with 300 grams of vinegar or 50 grams of acetic acid plus 40-50 kilograms of water per mu to enhance wheat resistance to dry and hot wind.

Fifth, do a good job of "one spray and three precautions" in the later stage.

The focus of wheat management in the later stage is to prevent diseases and insect pests, prevent premature senility and prevent dry and hot wind. In order to save cost and increase efficiency, in the later stage of wheat growth and development, according to the changes of weather, seedling growth and the occurrence trend of diseases and insect pests, the scheme of "one spray and three control" should be formulated, and insecticides, fungicides, foliar fertilizer or plant growth regulators should be reasonably mixed. 2 times from booting to the middle filling stage to achieve the goal of "one spray and three control". All localities should adjust the formula according to local conditions to make the formula more targeted, timely and scientific. The technology of "one spray and three prevention" should be vigorously promoted in both paddy land and dryland wheat fields.