How to grow sunflowers scientifically? Detailed explanation of key techniques
How to grow sunflowers scientifically? Here is an introduction and guide. Sunflower cultivation can follow the methods below: land preparation and sowing. Before planting, apply 30-35 dan of farmyard manure per mu or 25 dan of cattle pen manure, plus 3 dan of plant ash, then plow and harrow to form beds 2-2.5 m wide. Spring sowing of sunflowers is from late March to late April; the earlier the sowing, the...
How to grow sunflowers scientifically? Here is an introduction and guide
Sunflower cultivation can follow the methods below:
Land preparation and sowing. Before planting, apply 30-35 dan of farmyard manure per mu or 25 dan of cattle pen manure, plus 3 dan of plant ash, then plow and harrow to form 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 sowing or seedling transplanting can be used, with a planting density of 65×60 cm, one seedling per hole. Replanting and thinning. Sunflower seedling transplanting 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 seedlings are no more than 15-20 cm tall, thin to the final spacing, one plant per hole. Intertillage and weeding. Intertillage is generally done 3 times. The first is hand hoeing to thin seedlings and remove weeds; the second is weeding combined with final thinning and intertillage; when plants are 50-60 cm tall, earth up into ridges to prevent lodging. The herbicide "trifluralin" is effective on narrow-leaf weeds; use 300 g per mu mixed with 20 kg of water, spray 10 days before sowing, and harrow into the soil layer 10 cm deep to avoid seedling injury; 50% prometryn is effective on broadleaf weeds; use 200 g per mu mixed with 20 kg of water, spray within 3 days after sowing to kill germinating weeds, etc.
Pruning side shoots to control growth. Remove side shoots early to control unlimited shoot growth; applying nitrogen and potassium fertilizer at 7-8 pairs of true leaves works well. For fields without base fertilizer at sowing, early topdressing is required. At the first intertillage, 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-fertile; they can only set seed through artificial assisted pollination or cross-pollination by insects.
⑴ Artificial pollination: use soft cotton as a pollen puff to help pollen from different flower heads spread to each other on the flower disk. Pollinate during full bloom from 8-10 am (when the morning dew has not dried) and at 3 pm.
⑵ Bee pollination. When there is no strong wind or rain, release bees to pollinate.
⑶ During the seed-setting stage, supply fertilizer and water reasonably, increase potassium and apply phosphorus. 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% avermectin No. 2 at 1500 times dilution to control aphids, mites, etc. Harvest and seed saving. When the small florets in the center of the sunflower head wither and the seeds turn black, indicating maturity, harvest at the proper time. Select flower heads that are large, with short plants, thick stems, no pests or diseases, and plump seeds for seed. Place the seed-bearing flower heads for 3-5 days, then thresh and sun-dry.
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