THE IMPACT OF INSECT POLLINATION ON SEED AND YIELD CHARACTERISTICS OF SUNFLOWER (HELIANTHUS ANNUUS L.) LINOLEIC HYBRIDS IN THE CARPATHIAN FOOTHILL ZONE OF UKRAINE

This study examines the impact of exclusion of insect pollinators' access on the seed characteristics and yield performance of seven linoleic hybrids of Helianthus annuus L. developed by five seed companies (Euralis, RAGT Semences, DuPont Pioneer, Limagrain, and Syngenta).The hybrids were cultivated in the Carpathians foothill zone of Ukraine, on the fields of the company 'Continental Farmers Group' in Chernivtsi Region.We analysed the following seed characteristics: total number of seeds per head, total seed weight per head, 1000-seed weight, oil content, test weight, and biological yield.We found significant positive influence of insect pollination on seed characteristics and yield.Exclusion of pollinators led to statistically significant reductions in: total number of seeds per head (on average by ~1.2-2.7 times), total seed mass (by ~1.4-2.3 times), 1000-seed weight (by ~33-38%), oil content (by ~13-22%), test weight (by ~15-33%), and overall yield (by ~29-57%).ES Rosalia (Euralis) was found to be the most sensitive to the absence of insect pollinators, showing a significant decline across all analyzed characteristics.Among all the assessed characteristics, the total number of achenes per head was found to be the most sensitive indicator of the absence of insect pollination.Based on the results, the hybrids ES Rosalia (Euralis) and NK Brio (Syngenta) are recommended for cultivation in foothill regions, provided insect pollination is ensured.