How to grow sunflowers scientifically?

How to grow sunflowers scientifically? Please give instructions to sunflower planting can refer to the following methods: soil preparation and sowing. Before planting, apply 30-35 piculs of soil fertilizer or 25 piculs of cow pen manure per mu, add 3 piculs of plant ash, pear rake to make the border, the width of the bed is 2-2.5 meters. Sunflower spring sowing from late March to late April; the earlier the sowing, the higher the yield and quality. Direct seeding or seedling transplanting can be done with a planting density of 65 × 60 cm and one seedling per hole. Replenish seedlings between seedlings. The survival rate of sunflower seedling transplanting with soil is as high as 90%. Replanting should be early should be 1-2 pairs of true leaves, when the seedling height is not more than 15-20 cm, according to the row spacing to determine the seedling, one for each hole. Ploughing and weeding. It is generally ploughed three times. The first time hand hoe thinning seedling weeding, the second weeding combined with fixed seedling ploughing, seedling height of 50-60 cm to cultivate soil to prevent toppling. The herbicide "fluralin" has a good effect on narrow-leaf weeds, with 300 grams per mu plus 20 kilograms of water, sprayed 10 days before sowing, raked into the soil layer of 10 centimeters, free from seedling damage; 50% of the herbicide has a good effect on broadleaf weeds, 200 grams per mu with 20 kilograms of water, spraying within 3 days after sowing, killing sprouting weeds and so on. Control the length of the branch. 7-8 has a good effect on the application of nitrogen and potassium fertilizer to true leaves by using early forking to control infinite long forks. Fields that are not fertilized with base fertilizer when sowing must be fertilized early. For the first time, 12-15 kg ammonium nitrate or 25 kg ammonium bicarbonate or 8 kg urea plus 15 kg potassium chloride were applied. Auxiliary pollination. Sunflower self-pollination can not bear fruit, artificial pollination or insect cross-pollination can bear fruit. ⑴ artificial pollination uses soft cotton as a powder puff to help spread pollen from different discs to each other. It is pollinated from 8 am to 10:00 (morning dew is not dry) and 3 pm at full bloom. ⑵ was pollinated by bees. When there is no strong wind or rain, release bees to pollinate. During the fruiting stage of ⑶, fertilizer and water should be supplied reasonably, potassium should be increased and phosphorus should be applied. Prevent disease and kill insects. If leaf spot or rust occurs, it can be sprayed with 1500 times of Fenru Ning wettable powder; about 10 days after pollination, 1000 times of 40% dimethoate EC or 1500 times of 20% Aifudin 2 are sprayed to control aphids and mites. Harvest and leave seeds. When the withered seeds of the floret in the center of the sunflower disk turn black to show maturity and can be harvested at the right time. Choose the disk with large disk, short plant, thick stem and full grain free from diseases and insect pests to plant. Leave the seed on the disk for 3-5 days, threshing and drying. Click to get more sunflower planting techniques click to get more grain and oil crop planting techniques