INHIBITORY EFFECTS OF SEVERAL CHINESE MEDICINAL HERBS AGAINST PHYTOPHTHORA INFESTANS

Extracts from five Chinese medicinal herbs Galla chinensis, Rheum palmytum (root), Sophora flavescens (root), Terminalia chebula (fruit) and Magnolia officinalis (bark) were tested for inhibitory effects against Phytophthora infestans in vitro and in vivo, in order to select potential materials to develop an alternative for synthetic fungicides for the control of potato late blight.
The different extracts of the herbs varied in their mode of action against P. infestans. The G. chinensis extract was best at inhibiting sporangia germination, mycelial growth and infection on potato leaves. R. palmytum extract inhibited mycelia growth very well but not sporangia germination in vitro; the S. flavescens extract was less effective at inhibiting mycelial growth than sporangia germination. R. palmytum extract gave good control of infection of P. infestans on potato leaves. S. flavescens, T. chebula and M. officinalis, however, gave no protection to potato leaves against infection by P. infestans, even though extracts of T. chebula and M. officinalis inhibited P. infestans in vitro.
From these results, G. chinensis extract appears to have the most potential as an alternative control product for potato late blight in the future.

III International Late Blight Conference

Tongle Hu, Shutong Wang, Keqiang Cao, H.R. Forrer

plant extracts, potato late blight

https://doi.org/10.17660/ActaHortic.2009.834.23