Growth and yield of marigold flowers in response to mycorrhizal inoculation and phosphorus

ABSTRACT:

An experiment was carried out at greenhouse conditions in order to evaluate the effects of inoculation with arbuscular mycorrhizal fungi and phosphorus on growth and production of capitula of marigold (Calendula officinalis) plants. Inoculation with the arbuscular mycorrhizal fungi Glomus clarum, Gigaspora margarita and control (without fungus), as well as phosphate fertilization (50 mg/dm³⁾ or no fertilization were made. The experiment design was a randomized complete block, in a 3x2 factorial scheme, with four replications. In soils without addition of phosphate fertilizers, the inoculation of marigold plants with the arbuscular mycorrhizal fungi Gigaspora margarita resulted in higher plants (27.9 cm), with higher dry weight of the aboveground part (4.22 g/plant) and roots, more units of flowering capitula (16.5) and higher dry mass of flowering capitula (0.51 g/capitula) compared to non-mycorrhizal plants (19.8 cm, 3.49 g/plant, 7.0 and 0.22 g/capitula, respectively).

Keywords:
Calendula officinalis; Gigaspora margarita; Glomus clarum; phosphorus; medicinal plants; arbuscular mycorrhizal fungi.