Suppressing role of bio-organic fertilizers to Banana wilt disease

By: Jungmi Choi

Recently bananas have been seriously damaged by the fungal soil-pathogen Fusarium oxysporum f. sp. cubense (FOC) causing Banana Wilt Disease.  Since the pathogen’s spread has been extensive, preventative measures were undertaken by applying heavy loads of agro-chemicals.  However, the dormant nature of the pathogens render it difficult to eradicate them, even with the use of agro-chemicals, which resulted in resistance to the pathogens.  Wang et al. used Bacillus amyloliquefaciens as bio-organic fertilizer (BOF) as the bacteria efficiently controls various soil-borne pathogens.  It is believed that the lipo-peptides ( Iturin, Fengycin, and Bacillo-mycin D) from the bacteria contain components that inhibit fungal growth.  Based on previous reports, combining the bio-organic fertilizer with mature composts and antagonistic microorganisms increased the microorganism’s activity, resulting in its gaining popularity in China.  Wang et al. used four antagonistic Bacillus strains from different areas of healthy banana plants in diseased fields.  The researchers then combined the strains with organic fertilizers to observe how the wilt disease is being controlled and then stimulated growth.  These antagonistic strain isolates – WJA, WJ5, WJ22, and WJ25 – were selected for the experiment because they exhibited high survival rates in the soil.  All four stains contained B. amyloliquefaciens that are able to survive and exhibit strong antagonistic activity in the soil. The pot experiment resulted in significantly lower amounts of FOC treated with BOF compared to the control. Meanwhile, volatile compounds from the strains were poorly understood and need to be further studied.

(From Wang et al. 2015) This shows inhibitory activity of volatile substances: A-WJ5; B-WJ22; C-WJ25; D-WJA; and E as non-strain-inoculated (LB agar plate as a control)

 

Original article from;
Wang, J.J., Zhao, Y., and Ruan, Y.Z. (2015) Effects of Bio-organic Fertilizers Produced by Four Bacillus amyloliquefaciens Strains on Banana Fusarium Wilt Disease. Compost Science & Utilization 23, 185-198.