Sunflower is one of the most important and economically attractive crops of today’s agricultural production in Ukraine. The favorable price policy of the domestic and foreign markets encourages farmers to annually increase the acreage of this crop. However, unstable world prices for fertilizers force farmers to constantly save on them, which negatively affects the stability of productivity. But the agronomist’s task is not to save on fertilizers, but to optimize nutrition to obtain the highest yield and preserve soil fertility.
The majority of farmers have an imposed opinion that sunflower responds poorly to the level of mineral nutrition, so they apply, at best, 100 kg/ha of NPK in the fall and 100 kg/ha of urea or saltpeter in the spring and count on the natural fertility of the soil and favorable weather conditions. . However, this technology in most cases does not meet the expected results, because one-sided feeding does not contribute to obtaining a high yield. In addition to macronutrients, sunflower plants also require a certain amount of micronutrients, and their reservoirs in the soil are not unlimited.
Sunflower, despite its well-developed root system, which is able to penetrate to a depth of 2-3 m, and to develop horizontally from the trunk with a radius of up to 1 m, makes rather high demands on the conditions of mineral nutrition. Sunflower takes a large amount of nutrients from the soil, in particular nitrogen (N) and phosphorus (P 2 O 5 ) 1.6-2 times, potassium (K 2 O) 6-10 times more than grain crops. Depending on the processing conditions and varietal characteristics, the consumption of nutrients for the formation of 1 ton of seeds and the corresponding amount of by-products (stems, leaves, baskets) is: N – 50-60 kg, P 2 O 5 – 25-30, K 2 O – 150-180, Ca – 14 and Mg – 12 kg. The general level of removal of nutrients is determined by the yield and fertility of the soil. Accordingly, with a seed yield of 3 t/ha, the economic removal of the main nutrients by sunflower is: N – 135-180 kg/ha, P 2 O 5 – 75-90, K 2 O – 450-500, Ca – 35-45 and Mg – 30-35 kg/ha.
The need of sunflower for certain nutrients in certain phases of development is different, depending on this, the intensity of their absorption by plants is different. There are several critical periods. Thus, at the beginning of growth, it requires few nutrients, but their assimilation is ahead of the rate of increase in dry matter. During the first month of vegetation, sunflower uses 15% of nitrogen, 10% of phosphorus and 10% of potassium, although the accumulation of organic matter during this time does not exceed 5% of the maximum value. Sufficient provision of plants with nutrients after germination is of key importance for obtaining the planned yield, since the germinal meristem of vegetative and reproductive organs is formed in the growth cone at the early stages of organogenesis. With a lack of nutrients during this period, in particular nitrogen, significantly fewer leaves and flowers are laid. When plants are well supplied with this element, a large surface and mass of leaves are formed, in which a reserve of nitrogen-containing organic substances is created for their further transfer to seeds during pouring, leaves age more slowly after flowering, and the number of unfertilized flowers decreases. However, excessive nitrogen nutrition at the initial stages of development, on the contrary, leads to a decrease in the resistance of plants to adverse weather conditions, lodging and diseases, which in turn affects the level of crop yield and the quality of the crop.
The second critical period is the phases of budding (asterisks) and flowering. When the intensity of growth of vegetative mass and assimilation of nutrients accelerates significantly. During this period, the root system often does not cope with the full supply of plants.
A variety of stresses that constantly accompany plants during the growing season, such as drought or excessive moisture, low or high temperatures, and sharp fluctuations in night and day temperatures, also play an important role in the level of assimilation of nutrients by plants. And the application of insurance herbicides in the phase of 2-4 pairs of leaves also causes certain stress in plants.
One of the effective ways to balance and improve plant nutrition in stressful situations is foliar fertilization, which plays the most important role in increasing yield, since traditional (soil) fertilizers cannot independently provide plants with normal growth and development. The use of microfertilizers is especially important in critical phases of crop development, when it is necessary to provide a balanced nutrition of sunflower plants with trace elements to stimulate root formation and laying of baskets, which will ultimately affect productivity.
The research and production company “Evrosem”, an expert in sunflower, constantly conducts experiments on improving the technology of growing this crop in its own research fields “Fields of Knowledge” in order to obtain the maximum yield and profit. Many years of testing and improvement of nutrition technology led to the development of the innovative product EUROSTIM AMINO, which nourishes sunflower plants with a balanced composition of nutrients, and the amino acids in its composition help to pass the most critical phases of development with the least stress.
The main advantages of Eurostim Amino are:
- a balanced composition of nutrients, selected specifically for sunflower with the addition of humic substances, succinic acid and amino acids to nourish and relieve stress in the most critical periods of plant development;
- enriched with nitrogen, phosphorus and potassium in an easily accessible active form for the best absorption through the leaf surface;
- trace elements in chelated form dissolve well in water and are perfectly and quickly perceived by plants;
- has anti-stress, immunostimulating and fungicidal properties;
- compatible use with most plant protection products;
- non-toxic and safe for the environment;
- a relatively easy scheme and a long shelf life of the drug.
Eurostim Amino contains a balanced amount of microelements essential for sunflower plants, including boron, sulfur, copper, cobalt, molybdenum and manganese. Each of these nutrients plays an important role in the assimilation of macronutrients from the soil and through the leaf, increasing plant resistance to stress and forming a high yield. In particular, boron is the most important trace element for sunflower, it can be said to be irreplaceable. Foliar feeding of sunflower with boron allows you to maintain water balance, stimulate calcium absorption, activate the transfer of sugars, regulate the processes of pollination, pollen germination and fertilization, ensures the formation of a full-fledged basket and the accumulation of fats during pouring. Sulfur promotes effective assimilation of nitrogen, which is especially important during critical periods of plant life. Without it, the normal course of the processes of photosynthesis, growth, formation of amino acids and enzymes, oxidation-reduction reactions is impossible, it is responsible for the synthesis and accumulation of oil. Molybdenum participates in the synthesis of some important protein compounds, prevents the accumulation of nitrates, which negatively affects the formation of flowers. Copper is responsible for the culture’s resistance to drought, reduced temperature conditions, and plant lodging. Cobalt and manganese play an important role in the cycle of nitrogen assimilation, balanced formation of above-ground mass and root system, resistance to diseases.
The composition of Eurostim Amino also includes succinic acid and amino acids glycine, arginine and tryptophan, each of which has a positive effect on softening the passage of stressful periods with the least consequences and increasing the natural immunity of plants. Thus, glycine plays an important role in the synthesis of chlorophyll, regulating the work of the mouth of the leaves and the pollination process. It is a component of prostructural proteins that counteract the effects of dehydration or excess salt in plants. Arginine participates in the formation of the charge of the protein molecule, enhances cold resistance and the development of the root system, stimulates the synthesis of chlorophyll, alkaloids and hormones related to flowering and fruiting. Tryptophan is a material for the synthesis of auxin-type hormonal substances. Succinic acid increases natural resistance to stress, mitigates their consequences, regulates energy exchange in cells, works as a growth stimulator, increases plant immunity to diseases.
This entire complex of nutrients and amino acids concentrated in Eurostim Amino is, without a doubt, one of the most effective ways of leveling the impact of harmful environmental conditions and feeding sunflower plants. Long-term testing of the drug on experimental plots of the Field of Knowledge and production crops in many regions of Ukraine has shown its high effectiveness.
So at the “Fields of Knowledge” test sites in Kyiv and Poltava regions in 2019-2021. under different weather and climate conditions, the effectiveness of the Eurostim Amino preparation on the own sunflower hybrids of the Eurosem company was investigated. The experiments were carried out on the plots according to the field research method, in three repetitions, in four variants against the background of traditional cultivation technology (discification of the predecessor, plowing, early spring harrowing, pre-sowing cultivation, nitroammophoska fertilizers (16:16:16) 100 kg/ha, KAS 200 l /Ha). The years of the research differed dramatically in terms of weather conditions, so 2019 turned out to have a sufficient amount of precipitation, 2020, on the contrary, with a sharp lack of moisture, and 2021 – with excessive moisture.
According to the results, visual differences in the intensity of leaf coloration and the size of the leaf surface during the growing season of the sunflower of the variants treated with Eurostim Amino compared to the control were noted. A positive effect of treatment with the drug on the area of the leaf surface and the diameter of the basket was established with two treatments in the 2-4 leaves and “star” phase, regardless of the year’s conditions. The basket diameter increased by 7-9%, and the leaf surface area increased by 28 to 38% compared to the control.
The main result of the experiment is based on the obtained harvest. Despite the different weather conditions of the years of research, there is a positive reaction of plant productivity to Eurostim Amino treatment, especially in the phase of 2-4 pairs of leaves, when the generative organs of the plant are laid. Moreover, the maximum effect was obtained when using the drug Eurostim Amino when processing twice during the growing season (Fig. 1). In this case, the productivity of the hybrid increased from 2.8 to 3.8 t/ha depending on the year.
A characteristic feature of the dynamic process of leaf surface activity is its rate of drying. During three years of observations, it was established that in the variants with two treatments per vegetation period, the functioning of the leaves continued for 5-12 days. This indicates the effectiveness of the drug Eurostim Amino and the development of the root system. In addition, with an increase in the number of treatments, from one to two, there was a tendency to decrease the level of development of various diseases on plants. Additional nutrition in the most critical phases of development forms greater natural immunity, which also positively affects the level of productivity. The oil content in the seeds is of great importance for sunflower. Thus, the treatment of plants with Eurostim Amino in the experiments of the Field of Knowledge showed an increase in oil content by 1.5-3.2%, depending on the conditions of the year.
Of course, the cost depends on the number of treatments, but in any case, the economic effect far exceeds the control. The economic effect over the years of testing ranged from UAH 3.7 to 9.9 thousand per hectare.
In 2021, all crops on the hybridization sites of the Evrosem company in various regions were treated with Eurostim Amino. Regardless of the region and weather conditions, there is a positive correlation between the increase in the diameter of the basket, the weight of 1000 seeds and the area of the leaf surface. And thanks to the higher level of basket filling, the yield has also increased significantly.
Thus, in the Novoukrainskyi district of the Kirovohrad region, after treatment with the drug Eurostim Amino, the height of the plants of the hybrid Pegasus was 202.7 cm (in the control – 195.3 cm), the diameter of the basket – 19.2 cm (18 cm), the area of the leaf surface – 67 ,71 dm. (50.36 dm.), weight of 1000 seeds — 63.5 g (56.8 g), yield — 2.89 t/ha (2.8 t/ha).
In the Dnipropetrovsk district of the Dnipropetrovsk region, on production crops of the Ajax hybrid, treatment with the drug increased plant height by 10.2 cm, leaf surface area – by 15.6 dm, basket diameter – by 3.2 cm, weight of 1000 seeds – by 7.6 g, productivity by 3.6 t/ha.
In the Kyiv region, in the Skvyr district, the Arkon hybrid also showed positive results: on the crops treated with the drug, the height of the plants was 160.2 cm (on the control – 158.2 cm), the diameter of the basket – 22.1 cm (18.3 cm), the area of the leaf surface — 67.28 dm. (52.34 dm.), weight of 1000 seeds — 65.7 g (60.1 g), yield — 3.72 t/ha (on control — 3.56 t/ha).
The Avalon hybrid in the Pavlograd district of the Dnipropetrovsk region showed similar results: on the crops treated with the drug, the height of the plants was 192.6 cm (on the control – 184.1 cm), the diameter of the basket – 22.5 cm (18.9 cm), the area of the leaf surface – 68.12 dm. (53.46 dm.), weight of 1000 seeds — 68.4 g (62.1 g), yield — 3.5 t/ha (on control — 3.34 t/ha).
Practical experience shows that the system of foliar foliar fertilization of sunflower is highly effective. Thanks to this agromeasure, it is possible to increase seed yield up to 5 t/ha in commercial crops and up to 4 t/ha in hybridization areas.
Therefore, the inclusion of Eurostim Amino foliar treatment of crops in the traditional sunflower nutrition system has a positive effect on the growth and development of plants, contributes to the better development of the root system, increases the natural resistance of plants to diseases, improves pollination and the fullness of the basket, helps plants to overcome stress more easily and with less consequences due to unfavorable weather conditions, which, in turn, positively affects the formation of yield and maturity of seeds.