Selective effects of two systemic fungicides on soil fungi

Abstract

BAS 317 00F was not toxic to the total count of fungi after 2 days but was regularly significantly toxic at the three doses after 5, 20 and 40 days and toxic at the low and the high doses after 80 days. In the agar medium, it was toxic to the counts of total fungi. Aspergillus, A. terreus, Rhizopus oryzae and Mucor racemosus at the high dose. Only the mycelial growth of Trichoderma viride which was significantly inhibited by the three doses when this fungicide was added to the liquid medium. Polyram-Combi induced two effects on the total population of soil fungi. One inhibitory and this was demonstrated almost regularly after 2, 10 and 40 days and the other stimulatory after 80 days of treatment with the low and the high doses. In the agar medium, this fungicide was very toxic to total fungi and to almost all fungal genera and species at the three doses. Several fungi could survive the high dose. In liquid medium, the test fungi showed variable degree of sensitivity and the most sensitive was Gliocladium roseum which was completely eradicated by the three doses.

Potencial fungicida del árbol de neem contra el hongo Hemileia vastatrix

“…Entre los fungicidas sistémicos más estudiados se encuentran los triazoles como el fluconazol y las estrobilurinas (Figura 2), los primeros actúan inhibiendo la biosíntesis del ergosterol en hongos, mientras que las estrobilurinas inhiben la respiración mitocondrial (Bartlett et al 2002). Se ha observado que el efecto de los fungicidas sistémicos en el suelo tiene una persistencia de 80 días, eliminando hongos importantes de la biota del suelo (Abdel et al, 1982;Ratna-Kumar et al, 2017) Ante este panorama, es evidente la necesidad de buscar nuevas alternativas de control que sean eficaces (menos tóxicas y/o más activas) y más amigables con el medio ambiente. Una de ellas es el desarrollo de fungicidas naturales que posean nuevos mecanismos de acción con alta selectividad.…”