Antagonistic potentials of some soil fungi against three Post-harvest pathogenic fungi of carica papaya L.

Abstract

Four antagonistic fungi were isolated from the papaya field soil by serial
dilution and were identified as Aspergillus flavus Link., A. fumigatus Fresenius, A.
niger van Tiegh. and Trichoderma viride Pers. The soil fungi were selected to
evaluate their antagonistic potentiality against the three postharvest pathogenic
fungi of Carica papaya L. following "dual culture colony interaction” and volatile
and non-volatile metabolites. In dual culture colony interaction, out of four soil
fungi, T. viride showed the highest growth inhibition on C. gloeosporioides
(84.28%), F. nivale (95.23%) and Fusarium sp. (87.15%). On the other hand A. niger
showed the highest growth inhibition on C. gloeosporioides (77.39%), F. nivale
(98.63%) and Fusarium sp. (35.05%). The maximum inhibition of radial growth of
C. gloeosporioides (77.64%), F. nivale (58.76%) and Fusarium sp. (79.37%). were
observed in case of T. viride owing to the volatile metabolites. Whereas the
maximum inhibition of radial growth of C. gloeosporioides (58.23%), F. nivale
(37.43%) and Fusarium sp. (82.31%) were observed in case of A. niger owing to
the volatile metabolites. The maximum inhibition of radial growth of C.
gloeosporioides (90.90%), F. nivale (89.13%) and Fusarium sp. (76.84%) were
observed in case of T. viride owing to the effect of non-volatile metabolites. The
maximum inhibition of radial growth of C. gloeosporioides (92.42%), F. nivale
(73.01%) and Fusarium sp. (68.67%) were observed in case of A. niger owing to
the effect of non-volatile metabolites. Trichoderma viride and A. niger may be
exploited commercially as a biocontrol agent against anthracnose and fruit rot
pathogens of papaya.