Efficacy of Trichoderma bio-priming on tomato (Solanum lycopersicum L.) seedling development and early-stage pathogen...

The present investigation evaluated the impact of bio-priming tomato seeds (Solanum lycopersicum L., cv. Pusa Ruby) with Trichoderma harzianum on seedling establishment and the suppression of early-stage diseases under controlled conditions over two consecutive growing seasons (2023-24 and 2024-25). A pot experiment with a randomized complete block design was employed, comprising untreated seeds (T₀) as the control and bio-primed seeds (T_h), with three replications per treatment. Bio-priming substantially enhanced seed performance, as reflected in improved germination (96.73% in T_h vs. 68.42% in T₀) and superior seedling morphology. Root length increased from 5.90 to 8.70 cm, shoot length from 8.35 to 10.6 cm, and leaf number from 9.11 to 12.20 in T_h. Biomass accumulation was significantly greater, with fresh weight rising from 39.50 to 53.70 mg and dry weight from 3.95 to 5.36 mg, representing a 35.7% increase over T₀. These improvements translated into longer seedlings (14.3-19.3 cm) and elevated vigor indices. Moreover, T. harzianum bio-priming reduced disease incidence from 9.63% in T₀ to 3.22% in T_h, corresponding to a biological control efficacy of 66.6%. Collectively, the findings highlight the dual role of T. harzianum biopriming in promoting seedling vigor and conferring early-stage disease resistance, accentuating its potential in integrated tomato crop management.