Agrology (Nov 2020)
Formation of sunflower productivity under the influence of foliar top dressing by modern biopreparations in the conditions of the Southern Steppe of Ukraine
Abstract
The results of research with the culture of sunflower hybrid Dragan, performed du-ring 2016–2018 in the experimental farm of State Enterprise “Seleni Koshary” (“Green Barns”), located in the Pervomaiskyi District of Mykolaiv Region. Soil kind – southern chernozem with a content of 3.3–3.5% of humus in the layer of 0-30 cm and an average supply of mobile forms of nitrogen, phosphorus and potassium. Sunflower was placed after winter wheat. Under the primary (base) tillage, N16P16K16 was applied as the background. And in the main growing seasons foliar top dressing was carried out with modern preparations: Retardine, Fresh Energy and Fresh Flo-rida. The years of sunflower growing were typical for the Steppe Zone of Ukraine, but differed in the amount of precipitation. The main trends, regional features of sunflower growing, formation of its yielding capacity and seed quality are revealed. The importance of nutrition optimization by selecting micronutrients for the growth and development of sunflower for the benefits of foliar top dressing as a way to overcome the deficit in nutritive elements. The results of researches of influence of foliar top dressing in the basic periods of vegetation on productivity of sunflower are analyzed and stated. The importance of modern preparations in increasing the yielding capacity, quality and conditional collection (output) of oil per unit area has been studied. It is established that the yielding capacity of sunflower grain from foliar top dressing with modern preparations increases from 8.3 to 39.3% relative to control. Its highest level was formed during the treatment of plants twice during the growing season – in the phase of 3–4 pairs of leaves and the formation of anthodium (3.56 t/ha, in the control 2.76 t/ha). The highest yielding capacity is obtained in 2016, and the lowest – in the most unfavorable rainfall in 2017, when the increase in yields from foliar top dressing was up to 63.6%. This indicates the ability of plants under the influence of the studied biological preparations to withstand adverse conditions, in particular, high temperatures and drought during the growing season. In 2016, the increase in yield in the most optimal variants of nutrition reached 38.3%, and in 2018 – 29.6%. The fat content in the grain (kernels) of sunflower in more favorable years for moisture, compared to 2017, was also higher, but with the number of treatments of crops in contrast to the level of yield, this index did not increase. At the same time, the conditional collection (output) of oil from one hectare increased, which is due to the level of the formed yield. Thus, in the control the average indicator for 2016–2018 was 1.17t/ha, for the treatment of plants in the phase of 3–4 pairs of leaves – 1.40 t/ha, budding – 1.59, and in both phases – on average for all preparations 1.64 t/ha of oil. The obtained results gave grounds to substantiate a set of measures related to the optimization of sunflower plant nutrition through the use of modern growth regulators to obtain a stable grain yielding capacity and conditional oil output per unit area
Keywords