Synergy between Trichoderma spp. strains and substrate composition: keys to vigor in Hibiscus sabdariffa L

Abstract

Hibiscus sabdariffa L., has high agroindustrial and nutraceutical potential, which requires sustainable strategies to optimize its establishment in nurseries. The present study evaluated the influence of Trichoderma spp. strains on the germination and early growth of hibiscus seedlings under controlled and greenhouse conditions, considering their interaction with different substrate mixtures. During the germination phase, strains EDC-Q1 and EDC-S1 significantly increased (p ≤ 0.05) hypocotyl height, root length, and fresh root weight, without affecting the percentage or speed of germination. In the greenhouse, factorial analysis showed significant strain × substrate interactions in aerial and root variables. The combination EDC-S1 × peat (40%) + forest soil (60%) promoted the highest dry weight and root volume values, while the longest root length was recorded in EDC-Q1 × peat + forest soil. The results confirm that the biostimulant response of Trichoderma spp. depends on the interaction with the substrate, with the peat + forest soil mixture standing out as the most favorable for maximizing root vigor and initial crop establishment.