Detailed explanation of clever sunflower cultivation methods, easily master the planting techniques
Land preparation and sowing. Before planting, apply 30-35 dan of farmyard manure or 25 dan of cattle pen manure per mu, add 3 dan of plant ash, and use a plow harrow to make beds 2-2.5 m wide. Spring sowing of sunflowers is from late March to late April; the earlier the sowing, the higher the yield and quality. Either direct seeding or seedling transplanting can be used, with a planting density of 65×60 cm, one seedling per hole. Replanting...
Land preparation and sowing. Before planting, apply 30-35 dan of farmyard manure or 25 dan of cattle pen manure per mu, add 3 dan of plant ash, and use a plow harrow to make beds 2-2.5 m wide. Spring sowing of sunflowers is from late March to late April; the earlier the sowing, the higher the yield and quality. Either direct seeding or seedling transplanting can be used, with a planting density of 65×60 cm, one seedling per hole.
Replanting and thinning. Transplanting sunflower seedlings with soil has a survival rate as high as over 90%. Replanting should be done early and with small seedlings, at 1-2 pairs of true leaves, when the seedlings are no more than 15-20 cm tall; set the plants according to row and plant spacing, one plant per hole.
Cultivation and weeding. Generally cultivate 3 times. The first time, use a hand hoe to thin seedlings and remove weeds; the second weeding is combined with final thinning and cultivation; when the seedlings are 50-60 cm tall, earth up to form ridges to prevent lodging. The herbicide "trifluralin" is effective against narrow-leaf weeds; use 300 g per mu added to 20 kg of water, spray 10 days before sowing, and harrow it into the soil layer 10 cm deep to prevent seedling injury from the chemical; 50% prometryn is effective against broadleaf weeds; use 200 g per mu added to 20 kg of water, spray within 3 days after sowing to kill germinating weeds, etc.
Removing branches and controlling growth. Remove branches early to control unlimited branch growth; applying nitrogen and potassium fertilizer at 7-8 pairs of true leaves gives good results. For fields where no basal fertilizer was applied at sowing, topdressing must be done early. At the first cultivation, apply 12-15 kg of ammonium nitrate or 25 kg of ammonium bicarbonate or 8 kg of urea plus 15 kg of potassium chloride.
Assisted pollination. Sunflowers are not self-fruitful; they can only set seed through artificial assisted pollination or cross-pollination with the help of insects. (1) Artificial pollination means using soft cotton as a pollen puff to help pollen from different flower disks spread to each other on the disk. Pollinate during full bloom at 8-10 am (while the morning dew is not yet dry) and at 3 pm. (2) Bee pollination. In weather without strong wind or rain, release bees to pollinate. (3) During the seed-setting period, fertilizer and water should be supplied reasonably, with more potassium and phosphorus applied.
Disease and pest control. If leaf spot or rust occurs, spray with 15% triadimefon wettable powder at 1500 times dilution; about 10 days after pollination, spray with 40% dimethoate emulsifiable concentrate at 1000 times dilution or 20% Aifuding No. 2 at 1500 times dilution to control aphids, mites, etc.
Harvesting and seed saving. When the small flowers in the center of the sunflower disk wither and the seeds turn black, indicating maturity, harvest at the proper time. Select disks that are large, with short plants, thick stems, no pests or diseases, and plump seeds as seed. Place the seed-saving disks for 3-5 days, then thresh and dry in the sun.