Management measures of wheat field in spring during the critical period of wheat growth

After the Beginning of Spring, with the gradual rise of temperature, Huang-Huai wheat gradually entered the stage of turning green, getting up and jointing, and the seedling condition was generally good. This period is not only a critical period for determining the number and size of panicles, but also a critical period for management. First, some wheat fields with early sowing date, large sowing rate and sufficient fertilizer and water show a trend of vigorous growth before winter, and there is a potential danger of frost injury in spring and lodging and premature senescence in the later stage; second, the temperature is high before winter, and the occurrence of diseases, pests and weeds in some wheat fields is more serious; third, there has been less rainfall since November last year, resulting in rapid loss of soil moisture in some wheat fields and insufficient soil moisture; fourth, climate uncertainties have increased, and natural disasters such as spring drought and late frost are more likely to occur.

First, strengthen ploughing and repression. For the wheat fields that sow too early, sow too much, and the population is too large and too prosperous, root cutting or suppression should be carried out in time, and shallow and medium ploughing should be carried out for the three types of wheat fields with smaller populations, so as to increase temperature and preserve soil moisture, and promote the growth of roots and tillers. For wheat fields with straw returning, extensive soil preparation and soil warping, especially in dryland wheat fields without water irrigation, timely suppression and hoeing should be carried out in order to stabilize the soil, heal cracks, preserve soil moisture and increase temperature, promote strong roots and tillers, enhance drought resistance and frost resistance, and promote early and stable growth.

Second, according to the seedling system, classified fertilizer and water management. For the wheat field with insufficient soil moisture at present, the wheat field should be watered as soon as possible when the temperature is suitable. The first kind of wheat field (80 ~ 1 million / mu) should be controlled before and promoted later, and about 15 kg of urea should be applied in the middle and later stage of jointing combined with watering. In the second kind of wheat field (60 ~ 800000 / mu), 10 ~ 15kg urea per mu was irrigated at the beginning or early jointing stage to promote tillering and panicle formation. The three types of seedlings (less than 600000 / mu) should be mainly promoted, with urea topdressing 8kg / mu at returning to green stage, combined with watering at jointing stage, and then 5kg / mu to promote early development and rapid growth of seedlings. Late sowing wheat fields, it is necessary to control early spring watering, so as not to reduce the soil temperature and air permeability and affect the growth. The flourishing wheat field (1 million / mu) is mainly controlled, and it is generally no longer watered in early spring. Fertilizer and water management can be postponed to the middle and later stages of jointing, and the seedlings become weaker. For the dryland wheat fields without irrigation conditions, the hoe should be suppressed in time after the soil thawed in spring, and the soil moisture should be fertilized while the soil returned to slurry or light rain in early spring; in the areas with serious waterlogging damage caused by rice stubble and wheat, the ditches should be cleared in time, drainage and humidity should be reduced to ensure normal growth.

Third, we should focus on preventing the "three disasters". Prevent frost injury. The temperature in spring rises rapidly and fluctuates greatly, so it is very easy to have "late spring cold". According to the weather forecast, all localities should timely irrigate the prosperous wheat fields or soil suspended wheat fields before the cold spell comes, so as to improve soil moisture and prevent frost damage. Once the freezing injury occurs, remedial measures such as combining watering with quick-acting chemical fertilizer should be taken in time to promote small tillers to catch up with large tillers, promote the growth of frozen wheat seedlings as soon as possible, and reduce the loss of freezing injury to a minimum. two。 Prevent spring drought. At present, the soil moisture in some wheat fields is insufficient, and the frequency of spring drought is high, so we should pay close attention to the weather. The wheat fields with insufficient soil moisture, poor soil preparation quality and loose soil should be watered in time to protect seedlings, resist drought and frost, and promote normal growth. 3. Prevent lodging. For the wheat fields with large sowing rate, large population and the trend of prosperity and growth before winter, the wheat fields should be mainly controlled in spring, and some measures such as suppression, deep hoeing and spraying paclobutrazol, Maijujin, Maiyefeng, ton Tianbao and other growth inhibitors should be adopted to control spring tillering, restrain basal Internode elongation, build reasonable populations, cultivate robust individuals and prevent late lodging. Choose the right way of pesticides to prevent and control diseases and weeds. The disease should focus on monitoring wheat sheath blight, and correct road chemicals such as Xanthomonas cereus, diniconazole, tebuconazole and propiconazole should be selected to control wheat sheath blight and control wheat sheath blight during the period of turning green, and serious plots should be controlled again in 7 and 10 days after the first control. For the wheat fields that have not carried out chemical weeding before winter, after the spring air temperature has passed steadily through 6 ℃, fine weather can be selected from 10:00 to 4 p.m., and herbicides should be selected according to the types of weeds in the field, and the weeds can be removed in time. It is necessary to operate strictly in accordance with the appropriate concentration, use period and technical operating procedures of the pesticides used to avoid drug damage.