Fungitoxic properties of selected South African plant species against plant pathogens of economic importance in agriculture

Abstract

SummaryThirty‐nine plant species, representing 20 families from the subclasses Rosidae, Asteridae, Commelinidae and Liliidae, were collected from the Blyde River Canyon Nature Reserve, Mpumalanga, South Africa. Crude extracts were prepared and bioassayed, at equal concentrations, for their antifungal potential by determining the inhibitory effects on the mycelial growth of seven economically important plant pathogenic fungi. Statistically significant differences between plants and plant parts were observed as well as the resistance of different fungi to treatment with different plant extracts. The most significant mycelial growth inhibition was obtained with extracts from two species of the subclass Liliidae, namely Aristea ecklonii and Agapanthus inapertus. The crude extract of A. ecklonii performed best of all extracts as it totally inhibited the mycelial growth of all seven of the plant pathogenic test organisms and outperformed the inhibition by a broad spectrum synthetic fungicide (carbendazim/difenoconazole). Crude extracts of A. inapertus showed complete inhibition of four and strong inhibition of the remaining three plant pathogenic fungi. Although not as efficient as the previous two species, the extract of Anisopappus junodii, from the subclass Asteridae, also showed promising antifungal activity by completely inhibiting mycelial radial growth of two and strongly inhibiting that of the remaining five fungi.

Assessment of the Inhibitory Activity of Resin from Juniperus procera against the Mycilium of Pyrofomes demidoffi

“…The study in refs. [36,37] has confirmed that the strong antifungal property of semi purified extracts of several plants extracts.…”

Effect of extracts from in vitro-grown shoots of Quillaja saponaria Mol. on Botrytis cinerea Pers.

“…Another problem is that the synthetic fungicides are non-biodegradable; thereby presenting an environmental hazard for human beings, flora and fauna (Hayes and Laws 1991;Latorre et al 1994;Paulitz and Bélanger 2001). As the use of synthetic fungicides is being reduced globally, the search for natural alternatives of phytosanitary control has increased (Waard et al 1993;Pretorius et al 2002). In this context, antifungal properties have been confirmed in crude and semi-purified extracts of several plants (Duke 1990;Pretorius et al 2002;Meepagala et al 2003).…”

Impact of Quillaja saponaria saponins on grapevine ecosystem organisms

“…The current international trend is toward banning chemicals too toxic for the environment and human workers and to develop approaches based on biological molecules. In this context the application of crude plant extracts for the control of diseases and pests in crop production systems has the potential to offer a safer and less controversial alternative practice to chemical pesticides (Pretorius et al 2002).…”