Role of humic acid pretreatment on sugar beet (Beta vulgaris L.) seed germination characteristics and early seedling growth

Suitable germination and crops establishment are one of the most significant and fundamental issues that overshadow the economic performance of the product. Improving the quality of seeds by relying on their pre-treatment is one of the issues that can be considered. Accordingly, the present study was performed to investigate the effect of pretreatment of sugar beet seeds using humic in factorial experiment in 2017. The first factor was humic acid including four levels of zero, 8.33, 12.50, and 25.00 mg per 100 g of seed, and the second factor, cultivar included two levels of Ekbatan and Paya. According to the results of the analysis of variance, the main effects of humic acid and cultivar had a significant effect on all evaluated characteristics except root dry weight at one and five percent probability levels. Humic acid-cultivar interaction was significant only for the three characteristics of mean germination time, root dry weight, and shoot dry weight. Based on the mean comparison results, the seed vigor (87.87%), germination rate (6.27 bud/day), seedling vigor length index (3.52) and seedling vigor weight index (1269.96) were assigned to seed pretreatment using 12.50 mg of humic acid per 100 grams of seeds. Seed pretreatment without significant difference in the amount of coating material increased the uniformity of seed germination. Among the two studied cultivars, the Ekbatan cultivar was superior to the Paya cultivar in terms of all studied characteristics. In general, the use of humic acid improved the germination characteristics and early growth of seedlings.