Summer corn sowing is about to start in an all-round way. According to the forecast of the meteorological department, in the first ten days of June, there are high temperature and low precipitation in the Huang-Huai-Hai Region, possibly leading to drought in some parts, which will be unfavorable to the sowing and emergence of summer corn. In view of the current meteorological conditions and production situation, the National Agro-Tech Extension and Service Center (NATESC) has formulated technical opinions on summer corn production in Huang-Huai-Hai.
The first is to select improved varieties to raise the quality of seeds. It is necessary to scientifically select corn varieties with appropriate ripe period, high and stable yield, multiple resistance, wide adaptability and excellent comprehensive characters, especially those with strong resistance to close planting and lodging, drought, waterlogging, high temperature, little light and other abiotic stresses. In the north, the varieties with early maturity and strong drought tolerance should be selected; In the south, the varieties with moderate maturity, strong resistance to rust disease and high temperature should be selected; In addition, early-maturing, lodging-resistant, fast-dehydration varieties suitable for direct mechanical harvesting should be selected in places carrying out mechanical harvest. The germination rate of high quality coated seeds should be more than 95%, which can meet the requirements of mechanical precision sowing.
The second is to plant directly close to the corn stubble to improve the quality of sowing. Generally, it is planted in 60-cm line spacing and 3–5 cm deep. The single grain fine seeding machine with multi-function and high precision can be used to complete all processes of ditching, fertilization, sowing, soil-covering and suppressing at one time. Attention should be paid to the removal of the attachment on seed furrow after straw returning to destroy living places for diseases and pests. The seeds and fertilizer should be separated reasonably to avoid affecting seed germination and seedling growth. It is suggested that high quality special controlled-release fertilizer should be used to prolong fertilizer efficiency. If the soil moisture is not enough, seeds can be sown first, and then irrigate the field in time. Sowing should be completed in early to middle June in the south, and before 20 June in the north.
The third is to carry out close planting appropriately to improve the quality of the group. According to variety characteristics and production conditions, suitable planting density should be determined, to improve uniformity and establish high-quality population structure. Generally, 9.884–11,120 seedlings should be planted per ha; For high-density varieties or areas with better soil fertility and moisture, 12,355 seedlings can be planted. Spraying herbicides in time can effectively control weeds in the field, and removing small, weak and diseased plants in the field can improve the population uniformity. For the areas with high planting density, overgrowth and frequent wind disaster, plant growth regulators can be applied from jointing stage to tasseling stage, so as to improve the lodging resistance of plants.
The fourth is to coordinate the application of fertilizer and water to improve utilization rate. Restraining the growth of seedlings (for root development) should be launched in seedling stage to promote the growth the root and stem base, thus increasing the lodgging resistance of plants. Timely drainage should be carried out in case of waterlogging. Before the temperature becoming super high, irrigation should be carried out in time to reduce plant temperature and field temperature. Nitrogen fertilizer and moderate amount potassium fertilizer and micro-fertilizer should be applied in fields covered by former wheat straw. After fertilization, if the soil moisture is low, fields should be watered in time. It is better to promote the integration of water and fertilizer if permitted, to improve the fertilizer utilization efficiency.
The fifth is to strengthen monitoring of disaster, pests and dieases to reduce loss. Attention should be paid to weather changes such as summer drought, flood, high temperature and heat, typhoon and other disasters. Meanwhile, it is essential to pay close attention to the situation of diseases and pests, strengthen the monitoring and early warning of the second-generation armyworm, spodoptera frugiperda, and aphids. Especially, the northward migration of adult spodoptera frugiperda has peaked since May when is the seedling stage of summer corn in Huang-Huai-Hai Region. Agricultural departments should vigorously promote the unified control and joint prevention and control, and timely carry out plant protection measures to curb pests and diseases.
The sixth is to launch harvest timely to bring in every single grain. Without affecting the planting of next-stubble wheat, late harvest, mechanical harvest or direct harvest should be carried out according to the growth of corn. After harvest, corn should be dried in time to prevent mildew and improve yield and quality.