Key Points of "One Spray, Multiple Promotions" Technology for Autumn Crops
Currently, corn in main production areas is successively entering the flowering and milk stages, middle-season rice is in the booting and heading stages, and soybeans are about to enter the flowering and pod-setting stages. This is a critical period for yield formation and also the window for “one spray, multiple promotions”. However, the autumn harvest still faces threats from floods, high temperatures, drought, cold damage, and pests. During the middle and late growth stages of autumn crops, mixing and spraying foliar fertilizers, regulators, stress-resistant agents, and pesticides can achieve multiple effects such as promoting growth and development, grain filling and maturation, post-disaster recovery, and yield increase in one operation. This is a key measure for disaster prevention and yield increase in the middle and late stages of autumn crops. Adhering to the principles of “classified measures, optimal selection of fertilizers and pesticides, precise spraying, and ensuring safety”, we should promote the implementation of “one spray, multiple promotions” to fully consolidate the foundation for a bumper harvest of autumn crops.
(I) Adapt to Local Conditions, Implement Classified Measures
In Northeast China, spring corn is in the flowering and milk stages, spring soybeans are in the flowering and pod-setting stages, and middle-season rice is in the booting and heading stages. Focus should be on threats from waterlogging, low temperature and cold damage, early frost, as well as pests such as corn borers, bean leaf beetles, northern corn leaf blight, soybean sclerotinia stem rot, pod borers, rice blast, sheath blight, sheath rot, false smut, rice stem borers, and rice plant hoppers. In the Yellow River and Huai River Basin, summer corn is about to enter the tasseling and flowering stages, and summer soybeans are entering the flowering and pod-setting stages. Focus should be on waterlogging in the north and high temperatures in the south, as well as southern corn rust, brown spot, corn borers, fall armyworms, beet armyworms, cotton bollworms, soybean downy mildew, and pod borers. In the middle and lower reaches of the Yangtze River, middle-season rice is in the booting and heading stages. Focus should be on natural disasters such as high temperatures, drought, floods, and cold dew winds, as well as sheath blight, false smut, rice blast, rice stem borers, rice leaf rollers, and planthoppers. In Northwest China, spring corn is mostly in the tasseling and flowering stages, spring soybeans are in the pod-filling stage, and summer soybeans are in the flowering and pod-setting stages. Focus should be on drought and early frost, as well as bean leaf beetles, spider mites, soybean pod borers, and downy mildew. The implementation of “one spray, multiple promotions” should be comprehensive based on the growth progress of corn and soybeans, pest infestations, and natural disasters in each region.
(II) Optimal Selection of Fertilizers and Pesticides, Scientific Combination
To address natural disasters, areas with high temperatures and drought can spray potassium dihydrogen phosphate, water-soluble micronutrient fertilizers, and drought-resistant agents. Waterlogged fields can be sprayed with urea and potassium dihydrogen phosphate after timely drainage. Areas under threat of early frost can spray phosphorus and potassium fertilizers or liquid membranes. Corn growth regulators can include triacontanol, thidiazuron, brassinolide, and indolebutyric acid. Soybean growth regulators mainly include triacontanol, brassinolide, indolebutyric acid, brassinolide, thidiazuron, dinitrophenol·indoleethanol·brassinolide, 14-hydroxy brassinolide·thidiazuron, and calcium prohexadione. To address pests and diseases, corn fungicides can include pyraclostrobin, difenoconazole, pyraclostrobin·tebuconazole, azoxystrobin·difenoconazole, etc. Insecticides can include chlorantraniliprole, emamectin benzoate, deltamethrin, beta-cypermethrin, etc. Soybean fungicides can include pyraclostrobin, azoxystrobin, pyraclostrobin·difenoconazole, carbendazim·propiconazole, etc. Insecticides mainly include chlorantraniliprole, deltamethrin, beta-cypermethrin, abamectin·chlorpyrifos, etc. Rice fungicides can include tricyclazole, pyraclostrobin microsuspension, thifluzamide, azoxystrobin, isoprothiolane·tebuconazole, etc. Insecticides mainly include triflumezopyrim, tetraniliprole, indoxacarb, and spinetoram.
(III) Timely Spraying, Precise Dosage
Timing: Operations should be carried out when wind speed is below level 3 and temperature does not exceed 30°C, generally before 9 am or after 4 pm, avoiding the midday high temperature period. If moderate to heavy rain occurs within 24 hours after spraying, re-spraying should be done promptly. Night operations using drones can be considered according to local conditions. Dosage: When using drones, the spray volume should be more than 1.5 liters per mu, with the addition of an appropriate amount of spray adjuvant to improve droplet deposition, anti-drift, and anti-evaporation properties. When using high-clearance boom sprayers or vehicle-mounted frame machines for spraying, the spray volume should reach more than 30 liters per mu.
(IV) Unified Operations, Ensuring Safety
Before operations, give advance notice in accordance with relevant regulations. Set up warning signs during operations to prevent human and animal poisoning and accidents. Prioritize unified spraying operations using drones, controlling flight speed at 3-5 meters/second. Adjust flight height based on drone payload: for drones with payload under 30 liters, maintain 2-3 meters above the crop canopy; for drones with payload over 30 liters, maintain 3.5-4.5 meters above the crop canopy to prevent stem breakage during operation. Drone takeoff and landing should be away from obstacles and personnel. Operators should wear necessary protective equipment, avoid downwind positions of the spray, and strictly prohibit traversing the sprayed area. Smoking and eating are forbidden during operations. For fields unsuitable for drone operations, high-clearance boom sprayers or vehicle-mounted frame machines can be used for spraying as appropriate. Before spraying operations, comprehensively assess potential risks to prevent spray drift causing toxicity to non-target organisms and phytotoxicity to surrounding crops. Conduct small-scale trials before large-scale application.
