In vitro ANTAGONISM OF Trichoderma asperellum AGAINST Fusarium sp., CAUSAL AGENT OF CITRUS GUMMOSIS

Abstract

In this study, the antagonistic capacity of a strain of Trichoderma asperellum against Fusarium sp., was evaluated, which is identified as a causal agent of gummosis in Citrus sinensis. A completely random design was established, with three treatments (T1=T. asperellum versus Fusarium sp.; T2=T. asperellum; T3=Fusarium sp.) and 10 repetitions. The data for antagonism were obtained through the technique of dual cultures in potato dextrose agar (PDA) culture medium; and root growth inhibition percentages (RGIP) were obtained every 24 hours. The results indicated the degree of antagonism of T. asperellum (Ta15b), classifying it as 2 and 1 of the Bell scale, when confronting it against Fusarium sp.; the contact between hyphae was evident on the fourth day since being confronted. Significant differences were found (p?0.05) between the treatments; the RGIP varied from 71% to 86.6%. T. asperellum showed competition over space and nutrients against Fusarium sp. The results suggest that the first could be an effective biocontrol to reduce the radial growth of Fusarium sp.