The effect of nutrition on conidiation and conidial germination of Fusarium anthophilum obtained from barnyard grass (Echinochloa crus-galli)

An isolate of Fusarium anthophilum (A. Braun) Wollenweber (isolate 16C) has been considered as a candidate for microbial control of barnyard grass [Echinochloa crus-galli (L.) P. Beauv]. The effects of nutrition on conidiation, germination rate and germ-tube elongation of conidia of the fungus were evaluated. Conidia yield, conidial germination and conidial germ-tube elongation of the fungus grown in a liquid medium with a C: N ratio of 5:1 was significantly more than that in the same medium with C: N ratio of 15:1 or 40:1. Glycerol at 1, 2 or 5% (v/v) in the medium with a C: N ratio of 5:1, significantly enhanced conidiation of the fungus. The highest conidia production was obtained in the medium contained 5% glycerol. Glycerol did not enhance germination and germ-tube elongation. Harvested conidia in 0.2, 0.5, 1 or 2% Tween 40 resulted in higher germination and germ-tube elongation than those harvested in distilled water, when they were placed on top water agar for 8 h at 20 oC. The effect of Tween 40, particularly at 0.5% (v/v) was more pronounced after 9 and 35 days desiccation period at 20 oC and 15% RH.