Fungicides and Bacillus subtilis against fungi isolated from commercial seed of Side oats grama (Bouteloua curtipendula)

Abstract

Banderita (<em>Bouteloua curtipendula</em>), produces abundant and appetizing forage for cattle under extreme arid conditions. The demand for its seed in Mexico is a direct function of the potential for the establishment of pastures and therefore, the sanitary quality of this is fundamental. Phytopathogenic fungi affect the seed and establishment of prairies. The objective was to evaluate<em> in vitro</em> the effect of six agrochemicals and one biological against fungi associated with Banderita seed, to reduce losses caused by these. Treatments were carried out in PDA culture medium combined with Captan, Thiophanate-methyl, Mancozeb, Benomil, Prochloraz, Thiabendazole and <em>Bacillus subtilis</em> at concentrations according to the case of 0 (control), 0.005, 0.001, 0.05, 0.01, 0.5, 0.1, 1.5, 10, 100, 150, 200, 250 and 300 mg L-1, against <em>Alternaria alternata</em>, <em>Bipolaris cynodontis</em> and <em>Fusarium incarnatum</em>. The bi-directional colony diameter was measured every 48 h. The effective concentration of 50% was estimated by a non-linear regression model; in relation to the percentage of inhibition of mycelial growth. <em>Bacillus subtilis</em> presented higher mycelial inhibition 97% (P <0.05), followed by Thiophanate-methyl (96%), Prochloraz (94%), Captan (93%) and Mancozeb (92%). Benomyl and Thiabendazole showed low inhibition of fungi with 46 and 37%.<em> B. subtilis</em> and Thiophanate-methyl are the products with the greatest possibility of controlling pathogens associated with Banderita grass seeds.