The aim of this study was to investigate the effect of organic fertilization on growth, several physiological parameters and
yield of pepper plants (‛Buketen 50’). The field experiment was carried out at the experimental field of the Agroecological
Centre of the Agricultural University of Plovdiv (Bulgaria), which is certified as an ecological farm. For the purpose of the
research, the bio-fertilizer Lumbrical, produced by the Californian earthworm (Lumbricus rubellus), was used. Just before
planting, two levels of the bio-fertilizer were applied 50 and 100 ml per plant. Thirty days after planting, a part of the plants
were additionally fed with a solution of Lumbrical (200 ml per plant). During plant vegetation some biometrical indices
characterizing plant growth were measured. The content of the plastid pigments and the leaf gas exchange were taken into
account. The fertility of the pollen of the flowers was determined. The total amount of pigments in the dried and ground
red pepper was analyzed.