Effect of biostimulants on root yield and quality of carrots across different growing seasons

ABSTRACT Abiotic stresses are causes of losses in crop yield and quality. New technologies, including growth‐enhancing products, have been tested to mitigate this impact. The application of biostimulants has shown promise in managing biotic and abiotic stress‐related damage. This study evaluates the effect of a phytohormone‐based biostimulant on root yield and quality of two carrot cultivars across two contrasting growing seasons. Randomised block trials were arranged in a split‐plot scheme with four replicates. The carrot cultivars Nantes and Brasília were assigned to plots, and five Stimulate® doses (0, 5, 10, 15 and 20 mL L −1 ) to subplots. Traits assessed included root length and diameter, fresh and dry mass, root volume, β‐carotene, soluble sugar, pH, titratable acidity and total root yield. A combined analysis of both trials was conducted to investigate the effect of planting time on yield and quality. Biostimulant dosage influenced root length, with 12.91 mL L −1 , obtained by the regression curve, resulting in the longest roots during summer. Biostimulants had no impact on other traits, except for soluble solids, which decreased with increasing dosage. Brasília outperformed Nantes in all traits except titratable acidity. Midseason planting was advantageous for traits such as root fresh mass, total yield, root volume and diameter, especially for Brasília.