AGRO-ECOLOGICAL JUSTIFICATION OF THE APPLICATION OF FERTILIZERS AS AN ELEMENT OF THE ORGANIC SYSTEM OF GROWING OKRA

Abstract

Purpose. Studying the effectiveness of applying different types of organic fertilizers to obtain a crop of okra plants. Methods. The production experiment was carried out on okra plants during 2021–2023 in the educational production department of the Uman National University of Horticulture. Dibrova okra plants were grown in the experiment. Organic fertilizers studied in the experiment: litter-free poultry manure, rotted cattle manure, biohumus. Applying rates: poultry manure – 4 t/ha (before sowing, in furrows), rotted manure – 50 t/ha (applied in the fall for plowing), biohumus – 0.5 t/ha (for pre-sowing cultivation). Results. In general, it is possible to trace a clear tendency to increase the indicator of photosynthetic potential in plants of the variant with the use of poultry manure. At the first harvest of fruits, the photosynthetic potential indicator of the plants of this variant is 464 thousand m2/ha × days, which is 46 % more than the indicator of the control variant. In the phase of the beginning of flowering – the end of the fruit picking, the plants of the variant with the use of poultry manure also showed a better result – the difference with the plants of the control variant was 35.7 %. Similar conclusions can be drawn by analyzing the indicators in the phase of the end of fruit picking. During the three years of research, according to the number of fruits per plant, the plants of the version fertilized with poultry manure were the best – an average of 14.5 fruits per plant. This is 21.8 % more than on plants grown without fertilizer. The introduction of poultry manure stimulated the plants to form fruits 23.1 % larger than those of the control variant on average over the years of research. Over the years of research, the largest average increase in yield was obtained with the use of poultry manure – +1.6 t/ha. As for the plants of other fertilizer options, all of them also had a better yield rate than the control, in the range of 8.2–8.4 t/ha, which is 10.8–13.5 % more. Findings. Therefore, with the use of organic fertilizers, the photosynthetic potential of okra plants increases, productivity indicators improve, and, accordingly, yield. During the three years of research, according to the indicator of the number of fruits per plant and the weight of the fruit, the plants of the variant fertilized with poultry manure were the best. They formed the largest average yield – 9.0 t/ha.