Effectiveness of Bacillus subtilis Cohn (1872) and Trichoderma harzianum Rifai (1969) on Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder & Hansen, in tomato seeds (Solanum lycopersicum var. CENTA CUSCATLÁN)

Abstract

Vascular wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol), decreases the production and quality of the tomato crop. Currently, biocontrol with Trichoderma harzianum (Th) and Bacillus subtilis (Bs) has great potential, since its capacity has been demonstrated for a long time to inhibit phytopathogens; on the other hand, biopriming is a tool that improves germination, vigor, homogeneous emergence and seedling development. The objective of this research was to determine the effectiveness of the commercial strains Bacillus subtilis and Trichoderma harzianum on a Fol isolate in tomato seeds var. CENTA CUSCATLAN at an in vitro and in vivo level. The behavior of the biocontrollers at two concentrations and with biopolymers to inhibit the in vitro growth of Fol, stimulate seed germination and the development of tomato plants was evaluated. The results demonstrated the antagonistic capacity of the biocontrollers. In the in vitro bioassay it was verified that T9 (Th 10⁸ esp/ml^-1 + Al) increased the number of germinated seeds, while in the in vivo assay T6 (Th 10⁶ esp/ml^-1 + Ga) stood out for having greater germination percentage, but T8 (Bs 10⁸ esp/ml^-1 + Ga) reduced the germination time. The phenological variables: root length, stem length, total length, fresh weight and dry weight were higher with T5 (Th 10⁶ esp/ml^-1 + Al), while T4 (Bs 10⁶ esp/ml^-1 + Ga) favored the increase in stem diameter. This study is an effort to contribute to the application of innovative technologies and biocontrol methods to develop a sustainable agricultural production system, strategic in the face of current climatic conditions; besides being the first investigation and report of Fol in El Salvador.