How to plant sunflower closely? How to choose seeds? When is the best time to sow?

Sunflower, also known as sunflower, its seeds can be processed into snacks, or used to extract oil. Oil residue can also be used as feed and is one of the traditional cash crops. So how to plant sunflowers? How to choose seeds? When is the best time to sow seeds?

Seed selection

1. Variety selection: select excellent varieties with strong stress resistance, good yield and suitable for local ecological conditions, such as Gankui 1, Gangui 2, Gangui 3, etc., or other varieties suitable for local cultivation.

two。 Seed quality: seed purity is more than 98%, purity is more than 98%, germination rate is more than 90%, and water content is not more than 15%.

3. Seed selection: sunflower seeds were selected 4-5 days before sowing, and miscellaneous, shrunken and small seeds were removed, and then dried for 2-3 days, in order to increase seed vigor, germination rate and germination energy.

4. Seed treatment: soak the seeds in 25: 30 ℃ warm water for 3 hours before sowing, or soak the seeds in cold water for 6 hours, remove them to dry, stack them at 15: 20 ℃ for one day and night, and sow seeds with part of the seed coat opening.

Land selection, stubble selection and soil preparation

1. Land selection: select plots with deep ploughing layer, flat topography, good drainage and rich organic matter.

two。 Stubble selection: cereal crops are a good predecessor to sunflowers. In general, the number of years of rotation in production is 5-7 years. Do not repeat, meet stubbornness.

3. Land preparation

3.1Ridge in autumn: it is suitable for living soil layer 25~30cm, ploughing 20~25cm deep, deep loosening 30~40cm. To achieve no leakage ploughing, no bumps, timely application of farm manure or green manure ridging, and timely suppression after ploughing.

3.2Ridging in autumn: on the basis of autumn turning, raking and ridging should be carried out in time when 14cm is thawed in early spring to strictly prevent soil moisture running.

3.3 Deep loosening ridging: first loosen the original ridges and then break the original ridges to synthesize new ridges and suppress them in time.

3.4 Rotary tillage ridging: suitable for soybean, potato, corn and millet stubble. Ridging after rotary tillage should be carried out when thawing 14cm or above in early spring, and it should be suppressed in time.

Fertilizer application

1. Farm manure: combined with land preparation, 30-40 cubic meters of mature high-quality farm manure are applied per hectare.

two。 Green manure: a sufficient amount of green manure approved for use in combination with land preparation.

3. Chemical fertilizer

3.1Nitrogenous fertilizer: topdressing urea 100~150kg per hectare in the budding stage of sunflower, eliminating the use of nitrate nitrogen, the last topdressing must be carried out 30 days before harvest.

3.2Phosphate fertilizer: 60 ~ 75kg phosphate pentoxide was applied per hectare, combined with soil preparation as base fertilizer or seed fertilizer.

3.3Potash fertilizer: potassium oxide 35~50kg was applied per hectare, combined with soil preparation as base fertilizer or seed fertilizer.

Sowing at the right time

1. Sowing time: it can be sowed when the 5cm temperature of the soil layer is stable at 8: 10 ℃ for 3-5 days. Our general period is from May 15 to May 20.

two。 Sowing method: artificial on-demand sowing on ridges, or artificial on-demand sowing after ploughing and trenching. Dry land ploughing and water-on-demand.

3. Sowing method

3.1 artificial sprouting seeds: sitting water seeds in plots with soil water content less than 20%, and direct seeding seeds when soil water content is higher than 22%.

3.2 Precision point (hole) sowing of machinery on the ridge

4. Sowing depth: sowing depth 6~7cm, so that the depth is the same, the soil cover is uniform, and it reaches 4~5cm after suppression.

5. Sowing density: ridge distance 65cm, planting two ridges and one ridge, plant spacing 50cm.

6. Sowing quantity

6.1 artificial on-demand: sow 3 to 4 seeds per season.

6.2Mechanical sowing: sowing amount 12.5~15kg per hectare.

Field management

1. Interseedling: after emergence, a pair of true leaves will be thinned immediately, and when two pairs of true leaves will grow, one strong seedling will be left in each plant.

two。 Ploughing and weeding: three shovels and three times must be done. The first middle ploughing should be carried out early, when two pairs of true leaves of seedlings can be carried out, and ridges and deep loosening should be carried out in conditional plots. Shovel every 10 days or so after the first shovel and pick up the big grass in time.

3. Irrigation: irrigation should be timely and appropriate according to crop growth, especially in bud and flowering stage when drought occurs.

4. Forking: the small branches growing in the axils of the sunflower leaves and the ineffective small flower plates next to the flower plates should be knocked out in time.

5. Artificial pollination: a powder puff made of soft gauze, cotton or sponge that gently touches the disk after the dew dries in the morning. Bees can also be used for auxiliary pollination, with 15 cases per hectare.

6. Control of diseases, pests and weeds

6.1 Control of Sclerotinia sclerotiorum: rotation for more than 5 years can be adopted, combined with chemical control. Mix seeds with 0.5% pentachloronitrobenzene or 0.5% sclerotia.

6.2 Control of brown spot: selection of disease-resistant varieties, rotation, deep autumn ploughing, cleaning the countryside, and increasing application of phosphorus and potassium fertilizer can be adopted to control brown spot.

6.3 Control of sunflower borer: during the peak period of adult sunflower borer, 90 Trichogramma cards per hectare were evenly distributed in the field in two stages at an interval of 3 days. when the bees were released, the bee cards were attached to the back of the leaves with a curved needle. The larval stage (early August) was sprayed twice with 500-1000 times of 90% trichlorfon wettable powder per hectare, imitating more than 90%.

6.4 Control of grass damage sunflower Liedang: sunflower grows slowly after parasitism, plant becomes smaller, disk grows small, seed chaff is empty, thus reducing yield and quality. There are several ways to prevent and cure the list:

6.4.1 do a good job in the quarantine of sunflower seeds and do not allow propagation and production of sunflower seeds on plots where sunflower seeds have been grown.

6.4.2 rotation control is not allowed to plant sunflowers on parasite plots for 10 years.

6.4.3 artificial weeding during sunflower flowering when a large number of sunflowers are unearthed, artificial weeding should be carried out once or twice to remove the seedlings.

Harvest

The sunflower can be harvested when the maturity rate is more than 90%. Drying should be carried out in time after harvest, and ensure that there is no contact with sick and toxic substances to ensure the quality and hygiene of the products.