Suppression of Fusarium graminearum and Mycotoxin Mitigation in Durum Wheat by Trichoderma harzianum ITEM 3636

Durum wheat is highly susceptible to Fusarium head blight (FHB), a severe fungal disease caused primarily by Fusarium graminearum. FHB affects durum wheat production by causing significant yield losses and grain contamination with mycotoxins such as deoxynivalenol (DON) and zearalenone (ZEA). Given the limitations of chemical fungicides, finding sustainable biological control agents is essential. This study evaluated the antagonistic and biocontrol capabilities of Trichoderma harzianum ITEM 3636 against F. graminearum through in vitro and greenhouse experiments. In vitro dual and sandwich culture assays demonstrated that T. harzianum significantly inhibits pathogen mycelial growth through direct interaction and the emission of volatile compounds. In a competition test on rice kernels, co-inoculation with ITEM 3636 significantly reduced pathogen biomass, leading to maximum reductions of 96.5% for DON and 98% for ZEA. Furthermore, greenhouse trials on a commercial durum wheat cultivar revealed that T. harzianum ITEM 3636 significantly decreased FHB severity by 40% and reduced DON contamination by up to 32% only when a combined seed-coating and spike-spraying application was performed. Additionally, ITEM 3636 exhibited biostimulant-like effects on yield parameters, causing an increase in kernel weight of 33% in the greenhouse assay. These findings highlight T. harzianum ITEM 3636 as a promising and ecological alternative to synthetic fungicides for managing FHB, safeguarding crop production, and ensuring food safety.