Use of Chlorella vulgaris suspension as biofertilizer in sunflower cultivation in the conditions of the Republic of Moldova

Abstract

The present study evaluates the effect of Chlorella vulgaris suspension used as a biofertilizer in sunflower (Helianthus annuus L.) cultivation under field conditions in the Republic of Moldova during the 2025 agricultural year. The experiment included pre-sowing seed treatment, soil application, and foliar treatments with algal suspension, compared with a control treated with distilled water. Morpho-physiological and biochemical parameters were analyzed, including field emergence, plant height at different ontogenetic stages, yield, and seed quality indicators. Results showed that Chlorella vulgaris positively influenced early plant development, increasing field emergence by 4.90% (relative growth of 5.93%). Treated plants showed improved growth during early ontogenetic stages, while final yield increased by about 10%. Significant improvements were also observed in seed quality, particularly oleic acid content (+29.16%), oil content (+4.14%), and protein content (+2.11%). These findings highlight the potential of Chlorella vulgaris as an effective and sustainable biofertilizer that enhances sunflower productivity and quality while supporting environmentally friendly agricultural practices.