ARS | Publication request: Effects of surfactants on conidial germination of Myrothecium verrucaria

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2010
Publication Date: N/A

Technical Abstract: Myrothecium verrucaria has been employed as a unique biological control agent because it is highly effective against several annual and perennial weeds, including red vine, trumpet creeper, redroot pigweed, kudzu, hempsesbania and sicklepod. Although aerial conidia of M. verrucaria are hydrophilic, surfactants are still needed to improve the biological control efficacy on weeds, such as kudzu. The mechanism of surfactants, mainly wetting agents, such as Silwet L-77 that enhance bioherbicidal efficacy remains unclear. This study tested the effects of several commonly used surfactants on the germination of aerial conidia of M. verrucaria on PDA plates. Surfactants used in this study were Kinetic HV, Sorbitan Monolaurate, Tween 40, Silwet L-77 and Latron AG 98. Conidia were also suspended in DI water and then spread on PDA plates as control. Incubation was conducted at 25oC. Germination percents were taken at 6 hours and 9 hours, respectively. Results indicated that Silwet L-77 and Tween 40 significantly (P < 0.05) promoted initial germination in the first 6 hours when compared to the control. At 9 hours of germination process, there were no significant differences among all treatments. Quicker germination of conidia after application may contribute to the enhanced bioherbicidal efficacy.