The influence of plant extracts on root biostimulation in different strawberry (Fragaria × ananassa Duchense) cultivars

The use of botanical extracts is considered an important tool to stimulate plant growth, reduce the use of synthetic pesticides, or both. The impact of hydro-alcoholic extracts of Calendula officinalis, Salvia officinalis, Tagetes sp., and Taraxacum officinale on growth and root development of plants of five strawberry cultivars (‘Albion’, ‘Florence’, ‘Magnum’, ‘Rumba’, and ‘San Andreas’) grown in semi-field controlled conditions was tested in the present study. The vigor and growth of the five strawberry genotypes were significantly affected by the extracts, with cv. Florence consistently producing more biomass than any other variety compared to the untreated control. The extracts also impacted the root system differently depending on the specific genotype. However, the C. officinalis flower extract consistently improved the root architecture, increasing the value of five out of six parameters compared to the control. The genotype-related response points to the strong influence of the “variety factor” on the possible effect of plant extracts considered for biostimulation, plant protection purposes, or both, prompting the need for additional work to unravel the bottlenecks in using botanicals.