Suppression of plant diseases by reductive soil disinfestation using spent mushroom substrate of Flammulina velutipes

Abstract

Mushroom production by bed cultivation generates large amounts of spent mushroom substrate (SMS), posing a major challenge for the industry in terms of the cost-effective disposal of SMS. This study explores the potential of utilizing SMS as an organic material for reductive soil disinfestation (RSD). RSD treatment using SMS derived from the cultivation of Flammulina velutipes, Lentinula edodes, and Hypsizygus marmoreus effectively induced soil reduction. RSD using F. velutipes SMS resulted in significantly decreased offensive odors as compared to RSD using wheat bran, a typical organic material used for RSD. It also effectively decreased the densities of soil-borne pathogens such as Ralstonia solanacearum, Fusarium oxysporum f.sp. lagenariae, and Fusarium oxysporum f.sp. spinaciae in contaminated soils. In field experiments with contaminated soils, RSD treatment using F. velutipes SMS delayed the development of bacterial wilt in tomato own-root seedlings and suppressed the disease in grafted tomato seedlings. In addition, Fusarium wilt was significantly suppressed in spinach seedlings cultivated in RSD-treated soil. This study shows that SMS is a promising organic material for RSD, offering effective control of soil-borne plant diseases.