The plan of the year lies in the spring, the sting is coming, the temperature has warmed up in various places, and the winter wheat in the main producing areas is about to return to green one after another, which is the critical period to do a good job in spring field management and promote the transformation and upgrading of seedlings.
On the whole, the wheat population in the main producing areas was sufficient, the ontogeny was better, and the soil moisture was sufficient. However, there are also problems such as the coexistence of local strong and weak seedlings, large imbalance, small area of chemical removal before winter, obvious weed breeding, large temperature change in early spring, and high risk of cold in spring, which have an adverse impact on the management of wheat fields. In view of the current winter wheat seedling growth and climatic characteristics, all localities should adhere to it"Grasp the two ends, promote weak control and prosperity, fertilizer and water regulation, stabilize ears and increase grains, freeze and drought resistance, and prevent and control diseases and insects".It is necessary to strengthen the management of wheat fields in spring, promote the balanced growth of the crop, set up a good harvest shelf, and make every effort to seize a bumper harvest of summer grain.
Huanghuaihai winter wheat area
The proportion of wheat sown area at the appropriate time in this region increased compared with the normal year, the rain and snow were sufficient before winter and winter, the ground temperature was suitable, the soil moisture was good, and the seedling condition was better than usual. Current headwinds in the region:First, the polarization of seedlings in some fields is obviousThe coexistence of strong seedlings and weak seedlings is more prominent. Second, the hidden danger of diseases, insects and weeds is greaterStem base rot, sheath blight, aphids, etc. have been found in individual fields, and some of the weeds in the fields that have not been closed after sowing and removed before winter are heavier, and the pressure of spring chemical removal increases. Third, the temperature fluctuates in early springThe risk of "inverted spring cold" is high. Spring pipe toDue to the seedling policy, the combination of promotion and control, and classified management, frost prevention and drought resistance.
Wheat suffers frost damage.
(1) Regulate fertilizer and water according to the place and seedlings. To Wang Miao,Suppression or deep hoeing to cut off roots should be taken during the rejuvenation to the rising period to inhibit tillering breeding, and the plots with severe growth can be suppressed 2-3 times; It can also be chemically regulated during the rising period to moderately control growth and prevent lodging in the later stage; Postpone spring fertilizer and water management, top dressing and watering in the late jointing stage, and generally apply 8-10 kg of urea per mu; For wheat fields that are too prosperous before winter and have defertilization after returning to green, they should be watered by topdressing seedlings in the early or middle stage of jointing. To weak seedlings,After the beginning of spring, early cultivation and hoeing are carried out to improve temperature and moisture, and promote early emergence of seedlings; From the green to the jointing stage, combined with spring irrigation to fertilize diammonium or urea respectively, or with the help of spring rain (snow) topdressing to promote the growth of wheat, the total amount of diammonium and urea per mu is generally not more than 15 kg, to avoid watering too early to cause low ground temperature and delay the return to green. To the strong seedlings,In the late stage of getting up to the jointing stage, due to the irrigation of moisture topdressing, generally combined with watering to apply 6-10 kg of urea per mu to promote the steady growth of wheat. For wheat fields without irrigation conditionsAbout 10 kg of urea should be applied to the mu after the wheat returns to green to the rising period, and an appropriate amount of diammonium phosphate should be applied to promote the early onset and rapid growth of spring tillering. Wheat fields with heavy frost damageAfter the soil thaws, top dressing should be applied in time, generally about 8-10 kg of urea per mu, and about 15 kg of nitrogen and phosphorus compound fertilizer per mu of phosphorus-deficient plots should be applied to promote tillering into ears. At the jointing stage, nitrogen fertilizer or nitrogen and phosphorus compound fertilizer should be applied according to the seedling situation as appropriate to increase the number of grains per panicle.
(2) Suppress hoeing, protect moisture and increase temperature. Suppression in early spring can crush the soil clods, seal the cracks, solidify the frozen and thawed loose soil in winter, improve moisture, make the soil and the root system closely connected, and help the root system absorb nutrients; Hoeing can increase the ground temperature and reduce the evaporation of soil moisture. The combination of suppression and hoeing, first pressing and then hoeing, to achieve the effect of loosening the soil and solidifying, improving moisture and protecting moisture and increasing temperature, drought resistance and early emergence of seedlings. Hanging root seedlings and extensive cultivationWheat fields with more slumps and loose soil due to straw returning to the field should be re-irrigated after the soil thaws in early spring to resist drought and protect seedlings. For dryland wheat fields without watering conditionsAfter the soil is thawed, it is suppressed in time to promote the upward movement of moisture in the lower layer of the soil, which plays the role of moisture improvement, moisture preservation and drought resistance. For wheat fields with heavy frost damage before winter and overwinteringIt is necessary to take management measures to promote the transformation of weak into strong as soon as possible, and pick wheat or hoe in early spring to remove dead leaves and promote the early growth and rapid development of new leaves.
Suppression of wheat operations.
(3) Grasp the early and small, and prevent and control pests and diseases. Strengthen the early warning and forecasting of diseases, insects and weeds, scientifically formulate prevention and control plans, guide farmers to scientifically select medicines, use drugs safely, and timely prevent and control, joint prevention and treatment, and unified prevention and control. After returning to green, we should pay attention to the prevention and control of stem base rot, sheath blight, wheat aphid, wheat spider and other pests and diseases as soon as possible. Do a good job in the prevention and control of wheat stripe rust and other diseases in advance. It is necessary to comprehensively prevent scab during the heading and flowering period, and do a good job of "one spray and three preventions" during the flowering and filling periods. Pay attention to the spread trend of malignant weeds such as multi-flowered ryegrass, finch wheat, knotty wheat, Kanmai Niang, pig seedlings, etc., and choose fine weather from 10 a.m. to 4 p.m. for wheat fields that have not been removed before winter, so as to avoid frost damage.
(4) Use water to adjust the temperature to prevent frost damage. In early spring, we should pay attention to the weather forecast and prepare for the prevention and control of "inverted spring cold" in advance. Before the arrival of low temperature weather, the wheat fields with loose soil and unjointed should be suppressed to make up for the soil gaps, prevent wind and moisture, and control the vigorous growth; For wheat fields lacking moisture, irrigation should be carried out in advance before the arrival of the cold wave to improve soil moisture, adjust soil temperature and near-surface microclimate, buffer the impact of cooling, and prevent frost damage. Potassium dihydrogen phosphate and growth regulators can be sprayed outside the roots of jointed or boot-drawn wheat to reduce the impact of low temperature. 2-3 days after the cold wave, timely investigation of the freezing situation of young panicles, once frost damage occurs, take measures such as top dressing and foliar spraying fertilizer in time, and apply fertilizer in a classified manner. About 5 kg of urea per mu was applied to the wheat field with a freezing death rate of 10%-30%, 7-10 kg of urea per mu was applied to the wheat field with a freezing death rate of 30%-50%, and 12-15 kg of urea per mu was applied to the wheat field with a freezing death rate of more than 50 to promote the recovery of growth.
Winter wheat area in the middle and lower reaches of the Yangtze River
The proportion of wheat sown at the appropriate time in this region was higher than that of normal years, the seedling condition foundation was generally good, the winter precipitation was suitable, the temperature was high, and the average leaf age increased by about 1 leaf in the wintering stage. Present disadvantages:First, the sowing date lasts for a long timeThe seedling condition is complex, there is a certain proportion of vigorous seedlings, some late-sown wheat seedlings are weak, and the polarization of seedling conditions is obvious. Second, climate change is abnormalThe temperature fluctuation trend is obvious, and the risk of frost damage and lodging in spring is greater, and some wheat fields with poor furrow support have been damaged. Third, due to the large amplitude of temperature changes before winterThe proportion of chemical removal area is small, there are more weeds in some rice stubble and wheat fields, stripe rust occurs early, and scab is frequent and recurrent, which is difficult to prevent and control. Spring management should be adhered to"Efficient fertilization, strong control and weak promotion, green prevention and control, anti-stress and abundance".technical ways to strengthen the classification management of local and seedling seedlings.
(1) Stable and strong, reasonable fertilization. Strong seedling wheat field with suitable number of stem tillers for the populationWhen the leaf color is normal and the second internode at the base begins to elongate, the jointing fertilizer can be applied to 5-8 kg of urea and 10-15 kg of ternary high-efficiency compound fertilizer (content 15:15:15) per mu. High-yield wheat fieldAdvocate the application of booting fertilizer, master the application of half of the sword leaf (flag leaf) exposed, generally can be applied to 5-10 kg of urea per mu, there is a significant effect of increasing grain and weight. For weak-gluten wheat, nitrogen fertilizer was moderately moved forward, and jointing fertilizer was mainly applied. In order to avoid wheat greed and lodging due to excessive fertilization, it is necessary to grasp the period and total amount of top dressing. For wheat fields that are at risk of turning prosperousIt is necessary to control prosperity and promote growth through measures such as suppression and chemical control, and appropriately postpone fertilization to ensure the steady growth of seedlings.
(2) Control the prosperity and promote the weak, and optimize the group. For weak seedlings with small populations and insufficient spike counts and severely defertilized wheat fieldsAdopting the strategy of "promoting-oriented", 5 kg of urea and 15 kg of ternary high-efficiency compound fertilizer can be applied per mu; At the end of the second leaf to the sword leaf stage, 5-8 kg of urea per mu is conducive to preventing premature aging, high yield, quality improvement and efficiency. For wheat fields that are too large and at risk of lodgingThe strategy of "control-based" should be adopted to strengthen the application of measures to control and prevent falling, one is to suppress in a timely manner, and the vigorous seedlings should be suppressed in time before jointing, and suppressed 2-3 times in a row, the soil is too wet, the leaves are wet, frozen, saline-alkali soil, etc., and the wheat after jointing can not be suppressed; Second, from the beginning of the 5th leaf to the beginning of the 4th leaf, the foliar growth inhibitor can be sprayed to control the prosperity and prevent lodging; The third is to strictly control fertilization in early spring, appropriately postpone the application of jointing fertilizer, optimize the group structure, and lay the foundation for bumper yields.
(3) Timely elimination, prevention and control of pests and diseases. In spring, it is necessary to select suitable herbicides according to the grass phase, carry out chemical weeding in time, control weeds, pay attention to safe medication, and prevent low-temperature pesticide damage. It is necessary to pay attention to strengthening the prevention and control of sheath blight, powdery mildew, scab, rust, aphids and other pests and diseases. Powdery mildew and sheath blight are mainly to prevent late prevention and control, and scab should seize the critical period of prevention and control, so that flowers can be sprayed. Fall armyworm should be closely monitored and controlled in a timely manner. Highlight and strengthen the work of "one spray and three prevention", and pay attention to the mixed spraying of medicine and fertilizer in combination with pest control after heading, which can be sprayed with multiple prevention, green protection, premature aging, and grain weight gain.
Aphids are a pest on wheat.
(4) Dredging ditches and reducing stains and preventing drought. In spring, it is necessary to clear the ditch in time to manage the moisture, dredge the ditch system inside and outside the field, ensure the smooth drainage, ensure that the rain stops the field and the ditch is free of water, so as to prevent the occurrence of water. After spring, we should also pay attention to drought prevention, and irrigate jointing and booting water according to soil moisture. For wheat fields with a large amount of straw returning to the field, insufficient post-sowing suppression, and loose soil, when the soil moisture is suitable before jointing, choose sunny and frost-free weather to suppress as soon as possible, so as to promote the close connection of roots and soil, and prevent the loss of moisture and freezing of seedlings.
(5) Prevent frost damage and remedy it as soon as possible. Take the initiative to do a good job in the anti-freezing damage plan, and suppress, cultivate or spray chemical regulators in a timely manner to control the growth of Wangchangtian before jointing, so as to prevent the occurrence of frost damage. Before cooling, the fields lacking moisture should be irrigated in time to improve soil moisture, adjust the microclimate near the ground layer, reduce the temperature variation, and prevent low temperature frost damage. For wheat fields that have been severely frosted in winter, it is necessary to apply fast-acting nitrogen fertilizer in time to promote the recovery of growth, and the specific measures should refer to the Huanghuaihai winter wheat area.
Southwest winter wheat area
At present, the suitable wheat in this region has entered or is about to enter the jointing stage, and most of the soil moisture is suitable, the occurrence of diseases and insects is relatively light, and the seedling condition is generally good. However, due to the high temperature at the seedling stage, the growth process was faster than usual. Present disadvantages:One is that the fertility process is too fastThe growth of wheat field is vigorous, and the ability to resist low temperature and freezing damage in spring is weakened. Second, the local wheat field is late due to the sowing dateIt is difficult to transform seedlings in spring; The third is that some farmers blindly top dressingCombined with the factors of prosperity and growth, the risk of lodging in the later stage is intensified. According to the overwintering seedling condition in the region, it should be taken in spring"Focusing on control and promoting the combination of control".technical path, strengthen classification management, and build a good shelf.
(1) Control prosperity and steady growth, and promote the weak to become strong. To Wang Chang wheat field,Measures such as suppression and growth control or spraying of growth retardants should be implemented as soon as possible before jointing to delay the growth process and reduce the risk of frost damage and lodging in the later stage. At the same time, cancel, reduce or postpone top dressing, try not to irrigate or less irrigation. Wheat fields with weak seedlings sown lateIt should be mainly promoted, 3-5 kg of urea per mu should be applied, and foliar fertilizer should be sprayed under appropriate circumstances, which is conducive to the transformation of weak seedlings. To the strong seedlings of the wheat field,According to the established yield target to implement management, according to the sowing of the base fertilizer application to determine the number of top dressing, the total amount of pure nitrogen per mu during the whole growth period is controlled at 9-12 kg, high fertility, good foundation to take the lower limit, poor soil fertility, the number of seedlings slightly insufficient to take the upper limit.
(2) Clear ditches and manage moisture, reduce stains and prevent drought. The "three ditches" of rice stubble and wheat fields are particularly important, but there are many wheat fields in the production that do not open the side ditch, back ditch and box ditch, and even if the "three ditches" are opened, they rarely form an interconnection with the ditch outside the field, which makes the soil moisture content of some rice stubble wheat fields high, which aggravates the occurrence of staining. Wheat fields with over-wet soil are more likely to form weak seedlings, so it is necessary to clear the ditch in time to reduce stains and improve soil aeration. For rice stubble and wheat fields that have a tendency to be damagedDitches should be fully opened and cleaned to ensure that the ditch system in the field is connected with the ditch outside the field; Dryland wheat fields on high terrainIf possible, try to combine top dressing to replenish water, improve the quality of seedlings, and resist possible spring drought.
(3) Chemical weeding and pest control. At present, the disease in this region is relatively light, but the damage of aphids and red spiders in some fields is serious, and it is necessary to strengthen pest control at present. The high temperature during the overwintering period is conducive to the winter infection and reproduction of pests and diseases, and under the conditions of warm winter and early spring, the "central disease cluster" of stripe rust is most likely to appear in spring. If the wheat field has not been chemically weeded before winter, if the wheat has not been jointed, chemical weeding can also be carried out, and if it has been jointed, herbicides are prohibited. Low temperature is very easy to cause herbicide damage, should be strictly according to the requirements of different herbicides, choose sunny weather spraying.
(4) Prevent frost damage, control prosperity and prevent collapse. For the wheat fields with strong growth, the development should be controlled according to the population status to prevent lodging and low temperature frost damage. Once the low temperature below 0 that lasts for many days after jointing, the main stem of wheat will often be frozen to death, and the freezing situation of young panicles should be investigated as soon as possible after the cold wave, and timely classification and fertilization should be remediated to promote the recovery of growth. The specific measures refer to the Huanghuaihai winter wheat area.
Northwest Winter Wheat Region
The pre-winter moisture of wheat fields in this region is good, the winter rain is sufficient, and the seedling condition is generally good, which is conducive to the growth and development of dryland wheat. Present disadvantages:First, the threat of stripe rust is greaterThe area of occurrence before winter increased significantly compared with the same period of the previous year. Second, climate change is abnormalSome wheat fields have shown drought and frost damage; The third is the polarization of wheat seedlingsSome wheat fields in the irrigation area have vigorous growth, and the seedlings of late-sown wheat fields are weak before winter. In view of the seedling conditions in the overwintering period in this region, the management of wheat fields in spring should be carried out with reference to the winter wheat area of Huanghuaihai, and the spring management of dryland wheat should be carried outPromote weak control and drought resistance and cold protectionAs the center, do a good job in suppressing rake work in early spring, grasp water and fertilizer early, and implement policies for seedlings.
(1) Rake and suppress, improve temperature and promote growth. Since the beginning of winter, most of the rain and snow have been sufficient, and the first task at present is to do a good job in protecting the moisture of all kinds of wheat fields after the rain and snow. For wheat fields with good moisture and frozen soilIn early spring, when the surface soil thaws 2 cm, the early spring top rake can be taken to promote the early regreening and early germination. For wheat fields with less snowfall and poor moistureAfter the soil is thawed in early spring, measures should be taken as soon as possible to suppress and improve moisture to eliminate light and darkness. For the wheat fields of Wang Miao and Zhuang Miao,It is necessary to cultivate and suppress as soon as possible. For wheat fields with small populations and weak individualsIn early spring, after the soil has completely thawed, shallow hoeing and fine hoeing are implemented. At the same time, the irrigation area should also be hoeed in a timely manner after watering in spring or after rain to break the compaction.
(2) Water and fertilizer management, promote weak control and prosperity. For a class of seedlings,Prominent nitrogen fertilizer moved backward; A type of seedling wheat field that has not been watered in winter should be watered in the early stage of getting up; The first type of seedling wheat field that has been watered with winter water has good fertilizer and water conditions, and the total number of stem tillers per mu can reach 80-900,000 in the regreening stage, which can postpone fertilizer and water management to the jointing stage, control early spring tillering, and promote the steady growth of individuals. For the second type of seedlings,The focus is to properly promote tillering in spring, consolidate tillering before winter, and improve the tillering and panicle formation rate. The second-class wheat fields without winter water should be watered at the regreening stage, and 6-8 kg of urea should be applied per mu; The second type of seedling wheat field that has been watered with winter water should be watered and topdressed in the later stage, if the surface moisture is poor in the green stage, it can be advanced to the middle stage of the rise, and 5-7 kg of urea is generally applied in combination with watering per mu. For three types of seedlings,It should be promoted; The three types of seedling wheat fields without winter water should be watered in the early stage of returning to greening, and urea 5-7 should be applied in combination with watering per mu5 kg, diammonium phosphate 5-6 kg; For the three types of seedling wheat fields that have been watered in winter, the management of fertilizer and water in the regreening stage should be strengthened, mainly to promote; In the three types of seedling wheat fields with good moisture, do a good job of cultivating and hoeing in the early stage of regreening, improve temperature and moisture to promote early onset, increase early spring tillering, cooperate with watering during the rising period, and apply urea 7 per mu5-10 kg, with 3-5 kg of diammonium phosphate to increase the number of spikes. Late-sown weak seedling fields in dryland should be topdressed with fast-acting nitrogen fertilizer at the rainy and snow topdressing and early spring slurry return period, generally 5-7 kg of urea per mu, and 5 kg of diammonium phosphate can be applied to fields with insufficient phosphate fertilizer. For the wheat field, the fertilizer and water can be controlled in early spring, and the suppression or chemical control measures should be taken to control the growth in the early stage, and the fertilizer should be watered and fertilized in the later stage of jointing to prevent the fertilizer from weakening.
(3) Cultivating and chemical control, anti-freezing and anti-falling. Pay close attention to weather changes and be prepared to deal with the "cold spring". For the soil pine wheat field, it is necessary to suppress it as soon as possible; For the prosperous wheat fields, it is necessary to combine deep cultivation and suppression to enhance the ability to resist adversity. Wangchang wheat fields with lodging tendencies should be suppressed as soon as possible after returning to green, and chemical control measures such as spraying Zhuangfengan or paclobutrazol should be taken before jointing. Timely irrigation before a significant drop in temperature to stabilize the ground temperature, or take foliar sprays of potassium dihydrogen phosphate or plant cell membrane stabilizers and other growth regulators to prevent spring frost damage. After the cold wave, the freezing situation of young panicles should be investigated as soon as possible, and the fertilizer should be applied to save and promote the recovery of growth.
Weeding in wheat fields.
(4) Chemical weeding, disease prevention and insect treatment. For wheat fields that have not been chemically weeded before winter, herbicides should be selected according to the types of weeds in the field, and manual weeding can also be carried out in combination with cultivating and hoeing. When the leaf age of the irrigation area before winter is greater than 3 leaves and the leaf age of the dry land is greater than 4 leaves, chemical weeding can be carried out before winter, and the average daily temperature is more than 6 in the 3 days before and after spraying. Focus on the monitoring and green prevention and control of diseases (stripe rust, root rot, leaf rust, sheath blight, powdery mildew) and insect pests (red spiders, aphids), and do "accurate monitoring, reconnaissance with medicine, find a point, and control a piece" before jointing, and promptly guide farmers to scientifically select medicines, use drugs safely, prevent and treat them early, and control them in a unified manner.
**: Wheat Expert Guidance Group of the Ministry of Agriculture and Rural Affairs, National Agricultural Technology Extension Service Center