فهرست نشریات علمی دسترسی آزاد ایران

BACKGROUND AND OBJECTIVES: Shallot yields are significantly threatened by Fusarium wilt disease, caused by the fungus Fusarium oxysporum f.sp. cepae . Current control strategies primarily rely on synthetic fungicides and traditional cultural practices. To find a more sustainable and cost-effective alternative, this research explored the potential of microbial biocontrol. The objective of this study is to investigate the effectiveness of a biostimulant mixture composed of a seaweed extract from Ulva sp. and two endophytic bacteria isolates ( Bacillus subtilis DK5 and Kosakonia sp. DBS2) in controlling shallot wilt disease. METHODS: The effectiveness of this formulation was evaluated through assessments of bacterial antagonism, fungal mortality rates, and the biostimulant's production capabilities. FINDINGS: The findings of this study underscore the potential of endophytic bacterial isolates, particularly Bacillus subtilis DK5 and Kosakonia sp. DBS2 inhibits the growth of Fusarium oxysporum f.sp. cepae in vitro and suppresses wilt disease in shallot plants. Results indicated that the formulated biostimulants significantly inhibited pathogen growth across various concentrations. In vitro testing showed that a 2.5 percent biostimulant treatment led to a greater Fusarium oxysporum f.sp. cepae growth reduction than the control. Furthermore, under greenhouse conditions, the treated group exhibited significantly lower wilt disease severity (Probability ≤ 0.05) than the control group, suggesting that the biostimulant formulation effectively suppressed the disease. CONCLUSION: The bacteria demonstrated significant antagonistic activity and compatibility, making them ideal candidates for inclusion in a biostimulant formulation. When combined with Ulva sp. extract, the biostimulant mixture not only reduced disease severity by up to 58.76 percent but also enhanced key agronomic parameters such as plant height, leaf number, clump weight, and tuber dry weight, most notably at the 3.5 percent concentration. The biostimulant’s efficacy is likely due to both antimicrobial effects and growth-promoting properties, including improved nutrient uptake and phytohormone production. This study provides promising evidence for the integrated use of microbial and seaweed-based biostimulants as a sustainable alternative for managing Fusarium wilt and improving the productivity of shallot cultivation within a greenhouse environment.