Effect of humic substances on yield and nutrient contents of Eggplant Santana (Solanum melongena) plants in gray-brown soil

Humic substances promote the conversion of nutrients into forms available to plants. It also stimulates seed germination and viability, and its main effect usually being more prominent in the roots. This study was conducted in a randomized complete block design with three replications in Gobustan, Azerbaijan, in 2021 growing season, to determine the effects of different doses (0, 250, 500 and 1000 ppm) of humic substances such as humic acid (HA), fulvic acid (FA) and humic fulvic acid (HFA) on fresh yield and nutrient contents (N, P and K) of Eggplant Santana (Solanum melongena var. esculentum Santana) plants in a field experiment. According to the results of this study, humic substance treatments increased the fresh yields and leaf nutrient contents of Eggplant Santana, and this increase was found to be significant. The highest value for highest fresh yields and leaf NPK contents of Eggplant Santana plants were obtained from 1000 ppm HFA dose. These results suggest that 1000 ppm HA and FA combination to the standard humic substances application will be sufficient to obtain adequate fresh yield and nutrient contents in Eggplant Santana leafs.