Trichoderma viride AT85 Shows Powerful Biocontrol Against Potato Early Blight, Cutting Disease by 93%

A new study published in the Journal of Plant Pathology reports that Trichoderma viride AT85 offers a highly effective, sustainable solution for controlling early blight, one of the most destructive diseases of potato crops worldwide.

Potato’s Most Persistent Fungal Threat

Early blight, caused by Alternaria solani, significantly reduces yield and tuber quality. The authors collected four A. solani isolates from different regions and confirmed broad genetic diversity using RAPD-PCR markers (UBC 825, 826, 827). Two isolates (1 and 2) showed high virulence, making them critical targets for control strategies.

Discovery of a High-Performing Trichoderma Strain

From 100 rhizosphere isolates, the research team identified AT85, which showed the strongest antifungal effect against the most virulent pathogen. MALDI-TOF MS confirmed the isolate as Trichoderma viride AT85 with a high confidence log score of 2.25.

Chemical profiling via GC–MS revealed potent antifungal volatiles, including:

6-Pentyl-2H-pyran-2-one (21%)
β-Caryophyllene (16.3%)
Linalool, 2-phenylethanol, isobutyl acetate

These compounds are known to inhibit spore germination, disrupt fungal membranes, and trigger plant defense signaling.

In Vitro and Greenhouse Results

The strain displayed dose-dependent inhibition of A. solani, producing inhibition zones up to 67.3 mm at 150 mg/L.

In greenhouse trials:

Disease severity decreased by 93–95% compared with infected controls
Tuber weight increased by 45%
Overall yield rose 69%, especially in the second season

Activation of Plant Defense Pathways

Treated plants showed:

>100% induction of LOX1 and PR1a defense genes
52% reduction in oxidative stress marker MDA
Restoration of proline levels to near-healthy conditions

This indicates activation of both Induced Systemic Resistance (ISR) and Systemic Acquired Resistance (SAR).

A Promising Alternative to Chemical Fungicides

The authors conclude that T. viride AT85 offers a powerful, eco-friendly alternative to synthetic fungicides, with strong potential for integration into sustainable potato production systems.

Reference

Jalal, A.S., Sumayli, M., Alshaharni, M.O. et al. Trichoderma viride AT85 as a sustainable biocontrol strategy for early blight in potato: influences on morphological, physicochemical, molecular, and quality traits. J Plant Pathol (2025). https://doi.org/10.1007/s42161-025-02028-4