FORMATION OF BIOLOGICAL PARAMETERS OF FODDER BEET DEPENDING ON FOLIAR FERTILIZATION AND PLANT DISEASE PROTECTION UNDER THE CONDITIONS OF THE WESTERN FOREST-STEPPE OF UKRAINE

Abstract

The article presents the results of long-term field studies (2020–2024) aimed at investigating the effects of various foliar fertilizers and fungicides on the development of the leaf apparatus and photosynthetic parameters of fodder beet (Beta vulgaris L.) under the conditions of the Western Forest-Steppe of Ukraine. The study revealed significant differences in leaf area between the investigated varieties. The average leaf area of the Starmon variety was 56.31 thousand m²/ha, while that of the Olzhych variety was 48.18 thousand m2/ha. Foliar application of microfertilizers contributed to a significant increase in leaf area. The increase in leaf area with the application of the ADOB macro + micro fertilizer compared to the control amounted to 8.19 thousand m2/ha for the Olzhych variety and 9.19 thousand m2/ha for the Starmon variety. The maximum leaf area values were recorded under the combined application of microfertilizers and fungicides. For the Olzhych variety, the largest leaf area (54.58 thousand m2/ha) was observed with the ADOB macro + micro fertilizer in combination with the Impact fungicide, while for the Starmon variety, the same combination ensured a leaf area of 61.61 thousand m²/ha. The photosynthetic potential of the plants exhibited similar patterns. During the study period, the highest levels of this parameter were recorded during the period of intensive growth (August 10). The maximum photosynthetic potential in all experimental variants was observed with the ADOB macro + micro + Impact combination: 3.785 million m2 × days/ha for the Olzhych variety, while for Starmon, the same combination reached 4.531 million m2 × days/ha. Net photosynthetic productivity (NPP), as a key indicator of the efficiency of leaf area utilization for dry matter accumulation, also depended on varietal characteristics and agronomic treatments. The average NPP of the Starmon variety was 8.21 g/m2 per day, while that of Olzhych was 5.50 g/m2 per day. Foliar application of ADOB macro+micro increased NPP to 9.22 g/m2 for Starmon and to 5.80 g/m2 for Olzhych, and the additional application of the Impact fungicide further increased these values to 9.61 g/m2 and 6.17 g/m2, respectively. These results confirm the effectiveness of the combined use of microfertilizers and fungicides, which promotes the maximal preservation of an active leaf apparatus and enhances the photosynthetic productivity of plants, thereby ensuring an increase in the potential yield of fodder beet.