Effect of Biostimulants on the Productivity and Nutritional Value of White Cabbage (Brassica oleracea L. var. capitata)

The study examines the influence of humic and amino acid applications on the productivity and nutritional value of white cabbage (Brassica oleracea L. var. capitata). Two cultivars, ‘Bagočiai’ and ‘Kamienna glowa’, were investigated at the Lithuanian Research Centre for Agriculture and Forestry during the 2020–2021 period. The experiment was carried out in the experimental field where four different combinations of humic and amino acids were applied. Productivity and biochemical parameters were evaluated. It was determined that the application of amino and humic acids influenced the productivity of white cabbage. The obtained results showed that biostimulants enhanced the yield of heads up to 25% for cultivar ‘Bagočiai’ and 35% for ‘Kamienna Głowa’ compared with the control. The highest productivity, reaching 72.5–78.6 t ha−1 of cultivar ‘Kamienna Głowa’ and 74.9 t ha−1 to 76.2 t ha−1 of ‘Bagočiai’, was determined in the variants where amino acids and a combination of humic + amino acid were applied. The amount of vitamin C increased when plants were treated with an amino acid solution, while the highest crude protein content was found when plants were treated with humic acid.