There are several critical phases in the development of sunflower, one of them is 3 - 5 pairs of leaves.
On different types of soils, plants may lack the individual elements of mineral nutrition. Particularly, it is worth paying attention to nutrition of sunflower with boron. The content of boron in the soil in the amount of 5.0 mg / 1kg of soil is the minimum limit on which the first symptoms of a lack of boron begin to appear, and if its content is below 3.0 mg, these symptoms can be very strong.
Symptoms of boron deficiency
Symptoms of boron deficiency are manifested differently depending on weather conditions and hybrids. The upper leaves quickly become dry, dark and fragile.
Boron plays an important role from the moment of germination of seeds and next, from the regulation of carbohydrate metabolism, the synthesis of amino acids and proteins, chlorophyll, fertilization processes at the time of flowering. Boron is also important for the development of the root system of sunflower. It improves the outflow of carbohydrates to the root system and activates its growth. Due to the lack of remobilization (the ability to move from old fabrics to new ones), the need for sunflower bone remains high throughout the growing season, especially as it grows at the time of flowering. To provide sunflower plants with boron in the phase of 3 - 5 pairs of leaves, we recommend using Ecoline Boron Premium in a dose of 1.0 l/ha.
The use of boron in combination with L-α amino acids
The use of boron in combination with L-α amino acids contributes to the better and faster absorption of boron and mitigation of the negative effects of stress factors of different nature. In soils with low fertility and high levels of pathogenic diseases in the soil, it is advisable to conduct nutrition with a tank mix of Ecoline Boron Premium in a dose of 1.0 l / ha + GROS Phosphito NP 1.0-1.5 l / ha to enhance vegetative growth of plants and to control the development of diseases. Under the conditions of visual manifestation of individual nutrients' deficiency, or on the basis of a laboratory definition, other special fertilizers produced by the company "Ecoorganic" may also be used for foliar feeding of sunflower plants.