Middle and late management goals and priorities of winter wheat

At present, winter wheat in Shanxi Province has entered the jointing stage from south to north, which is also the key period of production formation and the high efficiency period of fertilizer and water management. In view of the current seedlings and sensation, it is necessary to promote weakness, control, and ensure stable growth of seedlings, promote the formation of panicles, increase the rate of ear formation, reduce the degradation of small flowers, increase the number of grains per ear, prevent lodging, prevent pests and diseases, and prevent dry heat. Improve the grain weight as the main target, strengthen the management of the middle and late wheat fields, consolidate the current foundation of the seedlings, build a reasonable group structure, actively respond to possible unfavorable factors, and strive to achieve a bumper harvest this winter.

I. Field management points There are still more than 60 days of wheat harvest in Shanxi Province, which is a key period for grain production. Generally, the number of ears of winter wheat in Shanxi Province is basically determined in the middle and late April, and the number of grains per ear is basically determined at the end of April or early May. At the same time, it is also a period of frequent occurrence of disasters such as spring drought, cold spring and dry hot wind. The temperature in the early spring of this year continued to be low, and the fertility progress of wheat was postponed, increasing the chance of suffering from dry heat and other disasters. Therefore, the management objectives in the middle and late stages are the number of spikes, the number of grains to be harvested, the weight of the grain attack, the control of the weak, the prevention and treatment of pests, and the prevention and reduction of disasters. High-yield water, high-yield dry land, classified guidance, scientific management of fertilizer and water, strengthen the management of the middle and late period, and win the initiative for the harvest of summer grain and high yield.

(1) Dryland wheat fields

1. Based on drought resistance, we must do a good job in weeding and weeding to ensure a good harvest.

As the temperature rises rapidly, soil evaporation increases rapidly, soil loss is severe, and rainfall in Shanxi Province is less than normal in March. Therefore, the management of dryland wheat fields is focused on cultivating and cultivating, loosening soil, reducing soil evaporation, eliminating weeds, inhibiting the growth of spring sorghum, reducing competition for competition, competition for water, and glory. Late sowing weak seedlings and de-fermenting wheat fields, we should also seize the effective rainfall process, apply 5-7.5 kg of urea per acre or ditch, increase the number of panicles, increase the number of kernels and grain weight.

2, film wheat to do a good job in the mid-term protection of the film, late release film to prevent premature aging

This year, the area covered by plastic film mulching wheat in Shanxi Province is 600,000 mu, and the spring wind is large, causing many layers of film uncovering and mulching damage, which greatly reduces the effect of film mulching. Therefore, for the wheat field where the damaged or uncovered film is present, an intermembrane soil protective film should be applied to seal the film with a large hole. At the same time, 10-15 days after wheat heading and flowering, film should be uncovered to reduce ground temperature, prolong grouting time, increase grain weight and prevent premature aging.

(2) Water wheat fields

1. Late-stage fertilization management measures for wheat fields

The three types of wheat fields with a total stem number of about 600,000 in the late stage are still mainly promoted in management measures. Water-saving is carried out as soon as possible, and 10 kg of urea is applied in combination with watering, to promote individual development, delay the differentiation of small toads, and increase the number of small and medium-sized donkeys. In the case of panicles, under normal circumstances, the number of ears per mu is increased by 10,000, and the per mu yield can be increased by about 10 kg, and the differentiation of small flowers is promoted.

2. Management measures for fertilizer and water in strong seedling fields

The strong seedling wheat field with a total stem number of about 800,000 can be postponed to the middle of the jointing stage for incremental irrigation (that is, the amount of irrigation water is not less than 60m3), and the urea is applied for 5-7.5 kilograms of urea, delaying the senescence of leaves and roots, and promoting the large grain of the ear. many. In general, for every 1 grain increase in grain per spike, the yield per mu can be increased by 10-15 kg and the grain weight is increased.

The total number of stems per mu is between 900,000 and 1 million. The soil moisture is better. The watering time should be postponed to the end of the jointing stage, and the urea should be applied 5 kg to promote the polarization of the big and small, anti-lost or greedy. Green and late ripening; wheat fields with poor soil moisture or de-fertilization symptoms should be watered in the early stage of jointing, and 5-10 kg of urea should be applied to prevent premature aging of roots and decrease in grain weight.

3. Wangmiaotian fertilizer and water management measures

For the large amount of sowing, the water and fertilizer in the early stage is sufficient, the total number of stems per mu is over 1 million, and there is a high-yielding wheat field that continues to grow. The main direction of management is to control the main prevention. The main technical measures are to spray the Zhuangfengan and other plants to delay the growth regulator, in order to shorten the length of the first and second internodes of the base, reduce the height of the plant, prevent lodging in the late stage; second, delay the watering of the jointed water, that is, in the wheat jointing In the later stage, watering and topdressing will be carried out to promote two-level differentiation, control and strengthen the population, build a reasonable group, reduce water and fertilizer consumption, improve the ecological environment such as ventilation and light transmission in the field, reduce the occurrence of diseases, and achieve more large grains. This kind of wheat field is mainly controlled. Once premature aging or de-fertilization occurs, it should be immediately watered and topdressed to prevent premature aging.

Second, artificially remove weeds, reduce water competition, competition for fertilizer, glory. At present, the wheat fields in southern Shanxi Province have entered the jointing stage one after another. It is no longer necessary to carry out chemical weeding. If there are many weeds in wheat fields, it should be manually removed to completely remove weeds and reduce Fight for water, fight for fat, and win glory, and reduce the weed base in the coming year. The weeds have been planted and should be completely burned after removal. It is strictly forbidden to discard. In particular, the section of wheat must be thoroughly removed before the wheat booting to prevent seed falling.

Third, do a good job of pest control Last winter before the winter, the temperature is high, powdery mildew, aphids and red spiders have a high winter base. Due to the low temperature in early spring this year, the winter wheat pests and diseases in Shanxi Province are relatively young, but with the rapid rise in temperature, it is expected In the late stage, the overall pests and diseases are moderately and locally biased. The area of ​​major pests and diseases will reach 30 million mu (times), and the characteristics of pests and diseases may be explosive and overlapping. Therefore, monitoring and forecasting should be strengthened, and early preparations should be made to achieve early detection, early prevention, and reduction of pest and disease losses.

(1) Wheat red spider: Single-row city ruler (33 cm) has 200 insects or 6 insects per plant. When most of the leaves are covered with white spots, the control index should be reached. It should be after 10 am to noon or 3 pm. After the windless weather, prevention and control. In the initial stage, use Lingling EC, triazophos EC, and avermectin EC. Spray evenly with 40 kg of water. In the case of serious occurrence, use dicofol emulsifiable concentrate, omethoate emulsifiable concentrate, glutinous WP, acetylene emulsifiable concentrate, avermectin emulsifiable concentrate, etc., and spray evenly with 40 kg of water.

(2) Wheat aphids: In the early stage of the wheat stubble in early April, the amount of 100 wheat aphids reached 200, using imidacloprid wettable powder, avermectin EC, anti-converse WP, acetamiprid EC, water 40 Evenly sprayed in kilograms. At the beginning of the flowering stage, the amount of 100 grams of wheat bran was more than 500, and it was sprayed evenly with 40 kg of omethoate emulsifiable concentrate, quetiapine emulsifiable concentrate, deltamethrin emulsifiable concentrate, high-efficiency cyfluthrin emulsifiable concentrate and matrine.

(3) Wheat larvae: adhere to the strategy of “main attacking and stagnation, adult worming”. When the sputum worms are in each side (10 cm × 10 cm × 20 cm), they should be sown in the middle and late April. Poisonous soil control. Generally, 50% phoxim emulsifiable concentrate or 40% methyl ethionine emulsifiable concentrate 200-250 ml with water or 48% chlorpyrifos emulsifiable concentrate 100-125mL/mu plus fine soil to make toxic soil, 3% methyl ethionite particles 2～2.5kg of fine soil and 20～25kg of fine soil are evenly applied to the wheat ridge, and then irrigated and watered in time. At the same time, in the adult stage (wheat heading, flowering stage), use 50% phoxim emulsifiable concentrate or pyrethroid to kill Insecticide 1000 ~ 1500 times liquid 40 ~ 50 kg spray in the evening.

(4) Wheat powdery mildew: from the end of the booting stage to the beginning of heading, when powdery mildew occurs sporadically, diniconazole wettable powder, moldy net (triazolone + carbendazim) wettable powder, uniform spray with 40 kg of water, concurrent treatment Major diseases such as wheat rust. During the flowering stage of panning, it can be sprayed evenly with triazolone wettable powder, ether fungus ester suspoemulsion, prochloraz emulsifiable concentrate, tebuconazole microemulsion, etc., and sprayed once every 7 days. In the filling stage, when powdery mildew occurs more seriously, it can be sprayed with 40 kg of water, such as triazolone wettable powder, diniconazole wettable powder, tebuconazole microemulsion.

(5) Wheat rust: adhere to the principle of “discover a little, prevent and cure one piece”, and through the inspection of the drug, find the central diseased plant and immediately spray it. Generally, triazolone wettable powder, tebuconazole water emulsion, powder rust WP, diniconazole wettable powder, carbendazim WP, evenly sprayed with 40 kg of water, interval 8-10 days, even Spray 3 times. A central disease group occurs before and after the booting, and when there is a large incidence, triazolone wettable powder, tebuconazole water emulsion, diniconazole wettable powder, flusilazole emulsifiable concentrate, etc., evenly sprayed with 40 kg of water, interval 8-10 Day, even spray 2 times. Before and after flowering, when the field is more serious, use tebuconazole water emulsion, diniconazole wettable powder, propiconazole emulsifiable concentrate, nitrile emulsifiable concentrate, triazolone wettable powder + carbendazim wettable powder, etc. 40 kg even spray.

(6) Wheat scab: adhere to the prevention and control strategy of “prevention first, active attack”. From the heading to the filling stage of wheat, if the rainy season is continuous, wet and foggy, and should be taken care of during hot weather. In the early stage of flowering, the sporadic incidence in the field is a suitable period for the control of wheat scab. Methyl thiophanate-wettable powder, carbendazim WP, diniconazole wettable powder, propiconazole emulsifiable concentrate, etc., can be sprayed with 40 kg of water, and sprayed once every 7-10 days.

4. Scientific prevention of natural disasters (1) Prevention and remedial measures for low temperature freezing damage

In the middle and late April, the wheat area in the southern part of Shanxi Province is in the period of jointing to booting. The wheat enters a period of rapid growth, the tissue is young, the water content is more, and the resistance to low temperature is weakened, especially the development of the young ear to the formation of the tetrad. Before and after the booting stage, it is extremely sensitive to low temperature and water shortage. If the minimum temperature is lower than 5 °C ~ 6 °C, it will be damaged, delaying the heading or extracting the white spikes, or some small spikelets in the wheat ears, only Partially strong, seriously affecting production.

The defense and remedial measures for low temperature and cold damage of wheat mainly include: watering, smoking or foliar application of foliar fertilizer before the onset of low temperature, and growth regulators such as Tianda 2116 (Zhuangmiaoling) can prevent and mitigate the occurrence of low temperature chilling. Once it occurs, it should be timely topdressed and watered to ensure normal grain filling and increase grain weight.

(2) Dry hot air prevention and remedial measures

From mid-late May to early June, Shanxi Province often encounters dry hot winds or dryness after rain, causing the leaves to dry and ripen and the grain weight to drop. Therefore, we should pay close attention to meteorological forecasting, and skillfully fill the wheat yellow water (watering during the filling stage is best to choose no wind and night watering), improve the microclimate in the field, and reduce the heat and dry wind hazard; or use acetic acid or chemical regulator before the onset of dry hot air. Foliar spraying, or combined with pest control to carry out "one spray three defenses" to improve wheat drought resistance, heat resistance, prevent dry hot air, increase grain weight.

Fifth, earnestly grasp the "one spray three prevention" wheat yield nearly 2 / 3 from the accumulation of photosynthetic products during the filling stage. The filling period is the most important period for the formation of wheat yield, and it is also a key period for preventing premature aging and increasing grain weight. Therefore, we must do a good job of “one spray and three defenses”, prevent dry hot air, prevent lodging, prevent pests and diseases, prolong the filling time, increase the filling rate, and promote the accumulation of photosynthetic products, so as to increase the grain weight and increase the grain weight, and not increase the grain weight. weight. Therefore, it should be sprayed 2-3 times according to the occurrence of pests and diseases and weather changes. In the initial stage of grouting, spray 0.2%-0.3% potassium dihydrogen phosphate solution, or 0.2% Tianda 2116 plant cell membrane steady-state agent solution, spray 50-60 kg per mu. Foliar top dressing is best carried out after 4 pm on a sunny day, and sprayed again at intervals of 7 to 10 days. If there is rain within 24 hours after spraying, it should be sprayed once. In order to simplify the operation, the foliar fertilizer can be applied in combination with a bactericide or an insecticide. For example, 50-80 ml of carbendazim emulsion per 50-80 ml, 50-75 ml of 50% phoxim emulsifiable concentrate, 50 g of Tianda 2116 plant cell membrane steady-state agent, 50 kg of water mixed into a mixture, and foliar spray The application can play the role of “one spray and three defenses” such as preventing disease, preventing insects, and preventing dry hot air.

Sixth, timely harvesting and drying of wheat wax is the best time for harvesting. It should be harvested in time and pay close attention to the weather changes. Before the wind or even rainy weather, it should be grabbed and grabbed to prevent falling or sprouting, to ensure that the particles are returned. . Dry in time after harvest to prevent rain and moisture, and select before storage to ensure purity and quality.