Biogenically engineered nanoparticles inhibit Fusarium oxysporum causing soft-rot of ginger

Soft-rot of ginger (Zingiber officinale) is the most important disease usually caused by Fusarium oxysporum (F. oxysporum) leading to significant yield loss. In this study, chitosan, copper and sulphur nanoparticles synthesised from leaf extract of selected plants were screened against two isolates of F. oxysporum recovered from the infected rhizome of ginger and soil samples. Moreover, among these, sulphur nanoparticles showed maximum inhibition of F. oxysporum isolated from soil samples (ZOI = 12.33 mm) followed by copper (ZOI = >12 mm) and chitosan nanoparticles (ZOI = >9 mm). Similarly, in the case of F. oxysporum isolated from infected ginger, sulphur nanoparticles showed maximum inhibition (ZOI = 13.33) as compared to copper (ZOI = >11 mm) and chitosan nanoparticles (ZOI = >9 mm). Considering the high efficacy, sulphur nanoparticles were further evaluated in combination with commercial fungicides, viz., bavistin, ridomil gold, sunflex and streptocycline. The combination of sulphur nanoparticles with bavistin demonstrated maximum inhibition (ZOI = 45.16 mm, MIC -20 µg/ml), whereas the minimum inhibition was shown by its combination with ridomil gold (ZOI = 10.5 mm, MIC -40 µg/ml). Therefore, it can be concluded that the combination of sulphur nanoparticles with bavistin can be used for effective and eco-friendly management of F. oxysporum causing soft-rot of ginger.