Trichoderma harzianum Suppresses Aflatoxins in Zea mays: A Biological Strategy for Pakistan’s Agriculture Industry

This study explores the use of endophytic fungi for the biocontrol of harmful aflatoxins (AFTs) in maize (Zea mays L.). The main objective of this study was to evaluate the effects of fungal pathogens and biocontrol agents on the corn seed germination and growth of seedlings under controlled conditions. Experiments were conducted under laboratory conditions in a growth chamber and in a greenhouse to assess the influence of environmental factors on seed performance and treatment efficacy. The growth chamber provided uniform conditions for physiological assessment while the greenhouses represented more realistic field conditions. Corn kernels were sown in sterile pots inside the growth chamber at standard conditions or in the greenhouse at controlled conditions and four treatment groups were established: untreated control seeds, seeds treated with non-AFT-producing (non-aflatoxigenic) strains (Trichoderma harzianum, T. asperellum and Aspergillus niger), seeds inoculated with AFT-producing (aflatoxigenic) strains (A. flavus and A. parasiticus), and seeds co-inoculated with both aflatoxigenic and non-aflatoxigenic strains (A. flavus and A. parasiticus with T. harzianum, T. asperellum or A. niger). High-performance liquid chromatography was utilized to detect and analyze the presence of AFTs. Co-culturing of A. flavus with T. harzianum resulted in a significant decrease in AFT levels, achieving a relative reduction of 99.3% compared to aflatoxigenic treatments alone. Among the isolates tested, T. harzianum and T. asperellum were the most effective at lowering AFT production of the aflatoxigenic strains, reducing the 5120 ± 560 µg/kg AFT level produced by A. flavus alone to 50.1 ± 1.10 and 63.1 ± 3.1 µg/kg, respectively. A. flavus negatively affected germination and early growth, whereas T. harzianum significantly enhanced both parameters. This study demonstrates that non-aflatoxigenic Trichoderma isolates can effectively mitigate AFT contamination and improve seedling growth, highlighting their potential as effective. sustainable, and locally adopted biocontrol agents for Pakistan’s chronic AFT problem under diverse environmental conditions—an area with minimal prior research and high national relevance.