What are the technical measures for promoting early maturity and preventing early frost in corn?

First, prevent drought and drain waterlogging to promote growth. From 10 days before tasseling to 20 days after tasseling is the period when corn needs the most water, consumes the most water, and is most sensitive to water in its entire life. According to soil moisture and seedling growth, irrigate timely and appropriately with tasseling and grain-filling water to effectively prevent "autumn drought" and promote large ears and full grains. September may be a rainy period, and low-lying waterlogged plots should be drained and dewatered in time to disperse soil moisture, avoiding severe yield reduction caused by lodging from waterlogging damage.

Second, fertilize reasonably to increase grains and grain weight. According to soil fertility, seedling condition and earlier fertilization, topdress in time. For fields with sufficient base fertilizer and intertillage topdressing and good growth, no further topdressing is needed; for fields with insufficient fertility, at the large trumpet stage, combined with irrigation or effective rainfall, open furrows on the side of the rows and apply fertilizer deeply, applying 25-30 kg of urea per mu, or using 150-200 grams of potassium dihydrogen phosphate per mu mixed with 30 kg of water for foliar spraying. High-yield fields may appropriately increase the dosage to accelerate the growth process, prevent premature leaf senescence, enhance root activity, and increase grain number and grain weight.

Third, use pesticides scientifically to prevent diseases and control pests. To control corn borer, armyworm, aphids, northern corn leaf blight, southern corn leaf blight, brown spot and other diseases and pests, strengthen monitoring and early warning, scientifically select pesticides, promote green control technologies such as using Trichogramma to control corn borer and using black light lamps or sex attractants for trapping and killing, comprehensively use various measures such as mechanical spraying and aerial control, and carry out emergency control and unified control at the appropriate time. For plants with disease, promptly remove diseased leaves at the bottom and take them out of the field for centralized burning to reduce sources of pathogen infection.

Fourth, promote early maturity and prevent frost damage. Adopt measures such as loosening autumn furrows, removing large weeds, cutting off empty stalks and diseased plants, removing bottom leaves, removing ineffective ears, stripping husks while standing for drying, and spraying potassium dihydrogen phosphate to improve field ventilation and light transmission conditions, reduce nutrient consumption, and accelerate grain filling. Prevent removing the middle and upper stems and leaves of corn too early, and promote the transfer of nutrients to the ears. For late-maturing varieties and low-lying plots, place rice husks, corn straw, weeds and other materials at the upper wind outlet and ignite them for smoking and fumigation to increase the local environmental temperature. Where conditions permit, spray plant growth regulators such as mepiquat chloride and chlormequat to enhance stress resistance and cold resistance.

Fifth, harvest late at the appropriate time to dehydrate and improve quality. Before early frost arrives, delay corn harvest as much as possible, make full use of corn after-ripening, extend the effective grain-filling time, and preferably carry out mechanical harvest when the husks are dry and withered, the black layer appears, and the milk line of the grains disappears. Spray corn dehydrating agent 10 days before harvest, at 60-100 ml per mu, mixed with 15-20 kg of water and sprayed on the three leaves at the ear, to accelerate grain dehydration, reduce moisture content, and improve yield and quality. For plants that stay green and mature late, harvest them in time for silage as feed. After corn harvest, stack them by arranging rows, putting them in barns, placing ears on the roof, and selecting and classifying ears to accelerate dehydration and prevent grain mildew.