Sunflower needs fertilizer rules (sunflower needs fertilizer characteristics)

Sunflower flowering period fertilizer requirement pattern

It is the turning point of sunflower growth. After flowering, root growth gradually slows down, and the above-ground part is still the stage of nutritional growth and reproductive growth, both the growth of stems and leaves, and the growth of flowers and flower discs. The content of protein and fat in sunflower seeds is very high, with crude fat content up to more than 40% and crude protein content up to about 30%, so the stage of carbon and nitrogen metabolism in the plant can still be maintained for a period of time after flowering. The nitrogen, phosphorus and potassium absorbed during flowering are 42%, 27% and 24% for edible sunflower and 31%, 31% and 24% for oil sunflower respectively. Increasing the level of nitrogen nutrients within certain limits increases the nitrogen content of stems, leaves and flower discs, which facilitates photosynthesis, synthesizes more carbohydrates and increases oil content. In addition, nitrogen is also necessary for the growth of flower discs and the formation of seed coat structural material.

Sunflower fertilizer requirements during maturity

Sunflower can enter the flowering stage 3 to 5 days after flowering, and gradually enter the maturity stage after pollination. The synthesis process in the mature plant is mainly the formation of oil and protein in the seeds. The oil of the seeds is converted from carbohydrates, which are photosynthetic products of the leaves, to the seeds later. The substances that can be transformed into oil and protein are called plastic substances. This substance can form both oil and protein, and because of these two possibilities, the protein and oil content of the seeds are in a reciprocal relationship. The direction in which the plastic material is transformed in the seeds depends on the external environmental conditions. Therefore, as early as after flowering, the level of nitrogen nutrition should be moderate, too much nitrogen supply will promote the conversion of plastic substances into protein, so that the oil content is relatively reduced.