THE EFFECT OF BIOLOGICAL PLANT PROTECTION ON SUNFLOWER PRODUCTIVITY UNDER IRRIGATION CONDITIONS IN SOUTHERN UKRAINE

Abstract

Perpose. To determine the impact of biological plant protection on the productivity of sunflower hybrids under irrigation conditions in the south of Ukraine. Methods. A set of general scientific methods and approaches of empirical and theoretical knowledge is applied: abstractlogical, statistical, modeling, generalization, two-factor field experiment. Results. During the entire vegetation period, significant differences were noted between hybrids and options for the use of biological preparations to protect plants from diseases according to the duration of the vegetation period. The highest values of this indicator – 129–132 days – were found in the Rimi hybrid using haupsin and Agat-25k seed treatment preparations. The growing season decreased by 17.2–21.7% when growing the yason hybrid without biological plant protection. During the formation of the basket, the maximum positive effect of the drug Agat–25k on the height of the plants of all studied hybrids was manifested. In the flowering phase, the difference between the options for seed treatment with biological preparations decreased to 3.3–14.5%, but the advantage of Agat–25k remained. According to factor a, the Rimi hybrid formed the highest height – on average 3.5–6.9% more than other hybrids. The largest indicators of the area of the assimilation surface at the level of 43.9–49.5 thousand m2/ha were observed in the rimi hybrid with treatment of sunflower seeds with the biological preparation Agat–25k. On average, according to the field experiment, in the phase of basket formation, the collection of dry matter was 0.61 t/ha, in the flowering phase, this indicator increased by 2.5 times (1.49 t/ha), and in the phase of full seed maturity, it reached the highest values - 3.53 t/ha, which was 2.4 times more than in the previous phase of development. Starting from the initial stages of organogenesis, the advantage of using Agat–25k biological preparation for pre-sowing seed treatment was evident, most of all for the cultivation of rr64e71 and Rimi hybrids. It was determined that on average for 2016–2018 and on average for factor A (hybrid), the maximum seed yield at the level of 3.17 t/ha was formed by the Rimi hybrid. According to the second studied factor (B – biological preparation), the advantage of the biological preparation Agat–25k was manifested in all studied sunflower hybrids. The РR64E71 hybrid had the best stress resistance -1.82. Genetic flexibility (2.83–3.17) was the highest РR64E71 and Rimi hybrids. The Rimi hybrid had the lowest variability (v = 14.8%). The breeding value at the maximum level – 2.00 was manifested in the variant with the Rimi hybrid. Conclusions. In field experiments, observation of sunflower plants made it possible to establish differences in the onset of phenological phases of development, as well as the difference and duration of interphase periods, growth dynamics, photosynthetic surface formation, accumulation of dry matter and yield in individual hybrids depending on the use of biological preparations to protect plants from pathogens.