Sustainable management of Fusarium diseases in durum wheat: field testing of seed and spike biological treatments

Fusarium Crown and Root Rot (FCR/FRR) and Fusarium Head Blight (FHB) pose significant threats to global durum wheat production, particularly in organic farming systems where chemical control is not available. This study explores biological control agents (BCAs) as sustainable and effective alternatives, validating laboratory findings under field conditions through differet application methods. To address seed-related infections, seed priming with beneficial bacterial strains was applied during open-field trials over two consecutive growing seasons (2023–2025) in the Ravenna area. Durum wheat seeds (cv San Carlo) were co-sown with autoclaved barley inoculated with Fusarium culmorum Fc1126. Early seedling emergence was manually recorded, with additional assessments at BBCH 30–31 stages using drone technology. In the first year, Bacillus amyloliquefaciens CAAd increased germination by 50% compared to untreated seeds, while LAB strains improved emergence by up to 37.3%. Drone surveys confirmed a consistent 15% emergence improvement for CAAd in both years, despite reduced disease pressure in the second season. For FHB trials at the University of Bologna Experimental Station, spray treatments with a LAB strain following artificial inoculation with F. culmorum (Fc383 and Fc820) and F. graminearum (Fg566 and Fg913) achieved the lowest disease index (13.8) in the first year. Its cell-free supernatant further reduced the FHB index to 4.2 in the second year compared to 7.6 in the inoculated control, suggesting potential antifungal metabolite activity. These results highlight BCAs’ potential as effective tools for organic durum wheat cultivation, with future research needed to optimize formulation and stability for enhanced practical use.