Abstract

FERNANDEZ BARBOSA, Reinel José  and  SUAREZ MEZA, Carol Libeth. ANTAGONISM IN VITRO OF Trichoderma harzianum Rifai AGAINST Fusarium oxysporum Schlecht f. sp passiflorae IN PASSION FRUIT (Passiflora edulis Sims var. Flavicarpa) FROM COLOMBIAN BANANERA ZONE MUNICIPALITY. Rev. Fac. Nac. Agron. Medellín [online]. 2009, vol.62, n.1, pp.4743-4748. ISSN 0304-2847.

Fusarium oxysporum Schlecht f. sp passiflorae cause withering of the passion fruit (Passiflora edulis Sims var. Flavicarpa), affecting their performance. In the search of alternatives for its control was carried out the present investigation with the objective of determining the antagonistic capacity of 6 strains of Trichoderma harzianum against the pathogen. 3 commercial strains were evaluated (TCC-001, TCC-005 and TCC-006) and 3 isolated from soil cultivated with palm oil in the Research Center Caribia of Corpoica (TCN-009, TCN-010, TCN-014). These were evaluated under conditions in vitro using the technique of dual cultivation in Petri plates with Agar Sabouraud. Competition for nutritious and space, micoparasitism and Percentage of Radial Growth Inhibition (PRGI) was evaluated, incubating them for 10 days at 28 °C. A totally randomized design settled down, with 13 treatments and 3 repetitions. All the isolates of T. harzianum exceeded in growth to F. oxysporum with a pathogen growth radiu averages (PGR) of 7.42 cm in dual culture. While the pathogen showed average radiu of 1.99 cm. TCN-009 and TCC-006 expressed the best results in competition for nutrients and space to grow 4 times faster than F. oxysporum and to reduce 3 times less the PRGI compared with the control, without significant differences between treatments (P=0.0001); also, produced the largest PRGI to 10 days with values of 64.61 and 65.91% respectively. There was no significant difference when comparing commercial and native isolates, but for the indigenous nature of the isolation, TCN-009 is, an in vitro level, more promising in the search for an antagonist in the control F. oxysporum in similar agroclimatic regions to the Bananera Zone Colombian.

Keywords : Biological control; withering; inhibition; competition; micoparasitism.

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