Control of postharvest rots of banana fruits by conidia and culture filtrates of trichoderma asperellum

Abstract

Banana fruits are highly perishable and prone to microbial infection that cause significant damage. Fungicides and pesticides that are used to control this infection are toxic to man and animals, hence there is the need for environmentally friendly control measures of fruit rot pathogens. Simultaneous inoculation of fruits with Trichoderma species and rot pathogens resulted in rot on the fingers, but rot produced by T. asperellum NG-T161 alone or in combination with the pathogens was reduced, compared to rot produced by the pathogens alone. Treatment of fruits with conidia and culture filtrates of T. asperellum NG-T161 for 30 min prior to inoculation with the pathogens provided a better control than their simultaneous application. Only Trichoderma species were recovered on plated portions of rotted tissues from inoculations with the pathogens and the antagonists on the fruits. At 50% (v/v) the filtrates inhibited the mycelial growth of Fusarium oxysporum and Colletotrichum musae by 49.7 and 60.3% respectively but Lasiodiplodia theobromae was not inhibited. T. asperellum strains were found to be mycoparasitic on banana fruit rot pathogens. Conidia and culture filtrates of T. asperellum NG-T161 controlled the rot on banana fruits. It could be developed into a biopesticide for the control of postharvest banana fruit rot pathogens.