The rain has arrived, Henan wheat has gradually entered the greening period, and the critical period of wheat spring management is coming soon. This period is a key stage to consolidate strong seedlings before winter, promote weak seedlings to grow stronger, and control vigorous seedlings. It is also a decisive victory for building a high-quality population structure, increasing tillering and panicle formation, increasing panicle formation rate, seed setting rate and thousand-grain weight, and winning a good wheat harvest. period. Therefore, we must not miss the farming season, take timely, scientific, and effective technical measures, do a good job in the management of wheat in spring, and make every effort to win a bumper harvest of wheat in 2021.
1. Analysis of meteorological conditions and overwintering seedlings since the wheat planting last year
1. The weather conditions during the sowing period are generally favorable, and the overwintering seedling conditions are generally good. One is the high quality of wheat sowing. During the wheat sowing period last year, the soil moisture was suitable, and most wheat fields realized”sow with suitable time and suitable moisture”. Technical measures such as deep plowing and deep plowing, soil testing and formula fertilization, seed coating and pharmaceutical dressing were implemented at a high rate, and most of them have been implemented. Miao Qi Miaoyun Miao Zhuang. The second is that the overwintering seedlings are in good condition. The condition of wheat seedlings during the wintering period in the province was better than that of the previous year and significantly better than normal. Among them, the first and second types of seedlings accounted for 88.5%, an increase of 1.3%over the previous year and an increase of 6%over the normal year.
2. Since the winter has been overwintering, the rainfall has been low, the drought phenomenon has begun to appear, and the risk of freezing damage in spring is high. One is that there are drought elephants in some wheat fields. According to the monitoring of soil moisture during the wintering period, the soil moisture of wheat fields in some areas of our province is insufficient, especially the soil moisture is poor, and drought conditions have begun to appear. Second, the risk of freezing damage in spring is high. According to forecasts by the Meteorological Department, affected by the”La Nina” event, there is a greater risk of a”spring cold” this spring.
3. Stripe rust has a small area for early onset and removal, and the task of controlling pests and weeds in spring is heavy. First, stripe rust occurs early, has a large number of incidence points, and spreads quickly; second, the temperature drops early in the winter, the area of chemical weeding is small, and the task of prevention and control in spring is heavy. At the same time, spring is also an important period for the occurrence and prevention of pests such as sheath blight and wheat spiders, which require timely monitoring and prevention.
Ⅱ. The main technical points of wheat spring management in Henan Province in 2021
According to the current wheat seedling situation and future climate change trends, the guiding principles for spring wheat field management in Henan Province in 2021 are:”Pests, pests, and weeds” are the main goal, with the construction of a reasonable population structure as the core, seedling policy, classified management, and scientific regulation, laying a good foundation for a high-yield wheat harvest in our province.
1. With the goal of cultivating strong stalks, multiple ears, and large ears, take measures to suit the local conditions and do a good job of fertilization and water management at the right time. According to seedling situation and seedling situation, all localities should scientifically manage water and fertilizer management, promote weak and strong, control prosperous and strong, stable and healthy growth, build a reasonable population, promote balanced development of spikes and flowers, promote polarization, and lay the foundation for high yield.
(1) Three types of weak seedling wheat fields (≤500,000/mu), mainly to promote the weak and strong, topdressing urea per acre during the rejuvenation period to the rising period About 15 kg, irrigation 35-40 m3 to increase the rate of panicle formation and increase the number of grains per panicle;
(2) The first and second types of wheat fields with strong seedlings are mainly for stable and healthy growth, which can be postponed to the early-mid jointing stage and then top-dressing and watering, and top-dressing urea per mu 10-15 kg, irrigation 35 m3, promote polarization and balanced development of panicles and flowers, and achieve large panicles and multiple grains;
(3) Prosperous and long wheat fields (≥1 million/mu), mainly to control prosperous growth, prevent prosperous and weak seedlings from being harmed by early spring cold, fertilizer and water management can be Postpone it to the middle and late stage of jointing, chase urea 10-15 kg per mu, combined with moisture content can be carried out at the same time as watering (about 35 m3 per mu).
(4) Late sowing weak seedlings and dry wheat fields should especially be watered early and top-dressing according to the situation, water and fertilizer should be coordinated, cost-saving and efficiency-increasing. When the relative water content of 0-20 cm soil is less than 60%in the greening stage, the jointing and booting stage is less than 70%, and the heading and flowering stage is less than 65%, appropriate supplemental irrigation should be timely and appropriate.
2. Strictly monitor the occurrence of diseases and insect pests, and conduct timely and accurate chemical control. From the turning green to heading stage of wheat, stripe rust, sheath blight, stem stalk rot, head blight, wheat spiders, aphids, etc. are the key targets for prevention and control, and precise prevention and control are implemented.
(1) For wheat fields that have not been chemically weeded before winter, chemical weeding should be carried out in time when the wheat turns green. After the average daily temperature has passed 6℃ stably, select the corresponding herbicides according to the types of weeds in the field, and spray them in strict accordance with the dosage and method requirements to ensure the weeding effect and avoid phytotoxicity;
(2)”Find one spot and prevent one slice” of stripe rust:spray triadimefon, propiconazole and tebuconazole and other high-efficiency chemical pesticides in time to prevent sporadic prevention Diseased leaves and disease centers, reduce the amount of bacteria source and reduce the risk of disease epidemic;
(3) Greening-joint stage is the key period for the control of wheat sheath blight and stem rot. Diniconazole, tebuconazole, and propiconazole are used , Shenzinomycin and other agents, spray the base of the stem of the wheat plant;
(4) Focus on the prevention and treatment of head blight:”Proactively attack and fight medicine when you see the flowers.” In the period of wheat ears to blooming, cyanostrobin, prothioconazole, tebuconazole, prochloraz, carbendazim, thiophanate, etc., and a combination of the above agents are used to treat wheat ears. Spray it. Continuous rainy weather is conducive to the occurrence of head blight. It should be controlled again after 5-7 days to ensure the control effect.
3. With the goal of pre-disaster prevention and post-disaster loss reduction, pay close attention to changes in weather and prevent low temperature hazards in spring.
The early spring temperature in our province rises rapidly and fluctuates greatly. The hazards of early spring cold are very prone to occur, especially due to the impact of the La Nina climate event this year. Attention should be paid to prevent the cold and late frost from mid-to-late March to early April, reduce floret abortion, and increase the number of grains per panicle. It is necessary to pay close attention to changes in the weather. Before the arrival of the cold current, the soil-deficient plots should be irrigated in time to improve soil moisture, adjust the microclimate near the ground layer, reduce the variation of ground temperature, or spray antifreeze biochemical control agents to prevent freezing damage. After freezing damage occurs, remedial measures such as top dressing, watering, spraying foliar fertilizer, plant growth regulators, etc. should be taken in time to promote the recovery of frozen wheat seedlings as soon as possible and reduce the loss of freezing damage.
4. High-quality wheat is scientifically regulated by type to ensure high quality, high yield and efficiency.
In areas where high-quality special-purpose wheat is planted, the spring management of high-quality wheat should be scientifically regulated and controlled according to the local climate, soil and the characteristics of the planted varieties. First, for strong gluten wheat, the nitrogen should be moved before and after, postpone the time of top dressing until the middle and late jointing period, reapply joint booting fertilizer, top dressing and watering should be carried out simultaneously, water filling period should be properly controlled, and nitrogen fertilizer or plant growth regulator can be sprayed in the later period to supplement nutrient. The second is to fertilize weak gluten wheat as early as possible, and pay special attention to the application of green fertilizer to avoid late topdressing. The third is the varieties with weak resistance to cold, pay attention to timely watering and jointing to prevent freezing damage; varieties with poor resistance to fall should return to green-chemical control at the beginning of the rise; varieties with poor resistance to diseases should be combined with disease-precision application to prevent disease Guaranteed.
Wheat Research Institute, Promotion Office
February 18, 2021