Technical opinions on Field Management of early Rice in the Middle and late stage of South China

At present, the early rice in South China entered the middle and late stage of field growth, in which South China entered the filling stage and the middle and lower reaches of the Yangtze River entered the jointing and booting stage. In view of the current early rice population growth and climate characteristics, the rice expert guidance group of the Ministry of Agriculture and the National Agricultural Technology extension Service Center discussed and put forward technical suggestions on the field management of southern early rice in the middle and later stage.

First, rational fertilization to promote growth. It is necessary to apply good fertilizer to the seedlings in order to promote early development and rapid growth. For the three kinds of seedlings of late sowing and late planting, one more tiller protection fertilizer should be applied to promote balanced growth. The first and second types of seedlings should focus on panicle and grain fertilizer, mainly flower protection fertilizer, fertilizing in the second leaf stage to prevent spikelet degradation, prolong the length of the first and second leaves, and promote tillers into spikes. For the fields with small population, fertilizer can be applied in advance when the inverted clover is drawn out, so as to achieve the combination of flower promotion and flower protection. According to the growth of grain seedlings in the field, apply nitrogen and potassium fertilizer in time to increase the number of effective panicles and grains per panicle, generally applying 3-5 kg nitrogen fertilizer and 3-5 kg potassium fertilizer per mu. If the leaf color is light green at heading stage, it is necessary to apply grain fertilizer, generally applying 1-2 kg nitrogen fertilizer per mu or foliar topdressing with 200 grams of potassium dihydrogen phosphate and 250 grams of urea to enhance the photosynthetic capacity in the later stage and promote grain filling.

Second, scientific water management and construction groups. On the whole, it is necessary to have water to grow ears in the middle stage of growth and dry and wet strong seeds in the later stage. In case of heavy precipitation, the open field should be drained in time. For late-developing fields that have not yet been exposed to the sun, we should adhere to the principle of "time to wait for seedlings", timely control of water and seedlings, to prevent cherishing water and seedlings, resulting in excessive population. After rewatering, dry and wet intermittent irrigation was used to promote root growth in paddy fields at the end of drying. During the heading period, shallow water irrigation is used to achieve water heading, which is conducive to the tidiness and maturity of heading. After heading, use dry and wet intermittent irrigation, cut off water about 5 days before harvest, avoid cutting off water too early to prevent premature senescence and high temperature forced ripening.

Third, comprehensive prevention and control of diseases and insect pests. Under the influence of the warm winter last year, the number of diseases and insect pests in the field and the population of rice planthopper abroad are on the high side, and the diseases and insect pests may be more serious in the middle and later stages of early rice. It is necessary to focus on the prevention and control of migratory "two insects" (rice planthopper, rice leaf roller) and "two diseases" (rice blast and rice sheath blight), vigorously promote centralized control, improve the effect of control, and reduce the amount of pesticides. Strengthen the monitoring of diseases and insect pests, appropriately increase the number of investigations according to weather changes, grasp the occurrence of diseases and insect pests, timely inform the information of diseases and insect pests, the time of application, pesticide selection and dosage, and generally carry out a key control in the break period of early rice to ensure that there are no major diseases and insect pests in the field in the middle and later stage.

Fourth, harvest at the right time and seize a bumper harvest. The early harvest of early rice affects the yield and quality, and too late affects the arrangement of the next crop. The harvest time is generally about 25 days after full heading, the whole ear loses green and 90% of the glume turns yellow. During the harvest of early rice in southern China, it is often accompanied by bad weather such as high temperature and torrential rain, and panicle sprouting is easy to cause yield and quality decline. It is necessary to guide farmers to harvest at the right time, prevent "cutting green", and ensure full maturity. Vigorously promote the mechanized combined harvesting with straw crushing device to improve the harvesting efficiency and realize the return of particles to the warehouse.