Resumo

GUEDEZ, Clemencia; CANIZALEZ, Luis; CASTILLO, Carmen  e  OLIVAR, Rafael. In vitro evaluation of Trichoderma harzianum for control of Rhizoctonia solani, Sclerotium rolfsii, and Fusarium oxysporum in tomato plants. Rev. Soc. Ven. Microbiol. [online]. 2012, vol.32, n.1, pp.44-49. ISSN 1315-2556.

This study determined the antagonistic capacity of T. harzianum isolates for control of Rhizoctonia solani, Sclerotium rolfsii, and Fusarium oxysporum in the roots of tomato plants. Six T. harzianum isolates were obtained from 6 municipalities of Trujillo State, using the direct inoculation of roots in acidified water agar technique. The antagonism was carried out in dual cultures using potato dextrose agar, incubated at 25 ºC, under a random design, with 18 treatments conformed for each T. harzianum isolate and each pathogen, 3 control treatments corresponding to each pathogen, and 3 repetitions per treatment, evaluating the mode of action and inhibition of radial growth at the third day. All the T. harzianum isolates showed rapid growth without significant differences among them (p>0.05), even though it was observed that T121 was more efficient as controller. When comparing the growth of the T. harzianum isolates with that of the pathogenic fungi, there were significant differences (p<0.05). Four T. harzianum isolates showed mycoparasitic action, and two antibiosis type action, which are characteristic mechanisms of these bio-controlling species. All the T. harzianum isolates studied can be used for the control of tomato pathogens

Palavras-chave : biological control; antagonism; Trichoderma harzianum; Rhizoctonia solani; Sclerotium rolfsii; Fusarium oxysporum.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )