GROWTH, DEVELOPMENT, AND PRODUCTIVITY OF EGGPLANT PLANTS IN THE RIGHT-BANK FOREST-STEPPE OF UKRAINE

Reseаrch has established a relationship between eggplant productivity and the timing of transplanting seedlings into open ground. Studies of the timing of planting seedlings in open ground showed changes in the duration of phenological phases of plant growth and development, in biometric parameters of plants and products, as well as the size of the crop and its quality. According to the research scheme and methodological recommendations, an experiment was conducted, which consisted of growing eggplant seedlings in a film greenhouse, with subsequent planting in the field at different times: the first decade of May, the second decade of May, the third decade of May, the first decade of June. The study examined the impact of transplanting dates on the growth, development, and productivity of eggplant plants. The findings revealed a significant influence on plant phenological indicators. It was determined that delaying the transplanting date shortens the duration of both the fruiting period and the total growing season. The duration of the fruiting period decreased from 50 days (early May) to 29 days (early June) – a reduction of 21 days. A similar pattern was observed for the "planting-to-fruiting" period: it ranged from 82 days for the eаrly planting date to 72 days for the late one. Early transplanting extended the fruiting period by 13 days and the total growing season by 6 days, whereas late transplanting (early June) reduced them by 8 and 5 days, respectively. The highest number of flowers per plant (22.3) was recorded for the transplanting date in mid-May, representing an increase of 2.2 flowers per plant compared to the control. At the onset of fruiting, the greatest plant height (76.3 cm) was observed with the mid-May transplanting date, exceeding the control by 11.9 cm. The number of fruits per plant ranged from 3.4 to 5.0. The highest fruit yield was obtained with the mid-May transplanting date (5.0 fruits per plant), an increase of 1.6 fruits per plant compared to the control. The high yield achieved with this planting date was accompanied by the highest marketable yield rate for the eggplants, at 87.2 %. Planting seedlings during the first ten days of May resulted in a yield of 26.1 t/ha – an increase of 21.2 % over the control – and a marketаble yield rate of 87.1%, which was 3.4% higher than that of the control. Planting during the first ten days of June yielded the lowest results: 17.5 t/ha (4.0 t/ha less than the control) and a marketable yield rate of 80.4 %. Biometric parameters of eggplant fruits are key indicators characterizing growth, development, and market quality; their formation depends largely on the seedling planting date and growing conditions. The highest fruit mass (159 g) was recorded for the planting date in the second ten-day period of May, exceeding other experimental variants by 13–31 g. The lowest fruit mass (128 g) was obtained when plants were planted during the first ten-day period of June. Fruit diameter and length were also greatest for the planting date in the second ten-day period of May (5.2 cm and 16.6 cm, respectively), exceeding the control by 0.7 cm and 0.9 cm. Planting eggplants at later dates resulted in less favorаble conditions for the development of these biometric parameters. The study estаblished that the most effective approach to eggplant cultivation is planting seedlings during the second ten-day period of May. Plants transplanted during this period exhibited the highest growth activity and produced the greatest yields, аlong with superior biometric parameters of the produce. A decline in efficiency was observed with transplanting dates in the first and third ten-day periods of May and the first ten-day period of June, as evidenced by reduced plant productivity and poorer biometric characteristics of the produce. Therefore, for the conditions of the Right-Bank Forest-Steppe of Ukraine, it is recommended to transplant eggplant seedlings into open ground during the second ten-day period of May; this ensures the fullest realization of the crop's potential and the production of a high-quality harvest.