In vitro and in vivo antifungal activity of crude extracts and powdered dry material from Ethiopian wild plants against economically important plant pathogens

Abstract

In Ethiopia extracts from specific plants are used traditionally as natural fungicides in small scale farming systems where synthetic chemicals are out of reach of the average subsistence farmer while no scientific base exists for this practice. Subsequently, methanolic crude extracts from Dolichos kilimandscharicus and Maerua subcordata roots as well as Phytolacca dodecandra berries were screened in vitro for antifungal activity against Botrytis cinerea Pers.:Fr., Fusarium oxysporum Schlechtend.:Fr., Sclerotium rolfsii Sacc., Rhizoctonia solani Kühn,, Botryosphaeria dothidea (Moug.:Fr.) Ces & De Not. and Pythium ultimum Trow, using an agar diffusion method. Compared to the other plants as well as specific standard fungicides for each pathogen, the root extract of D. kilimandscharicus showed the highest broad-spectrum in vitro antifungal activity by inhibiting the mycelial growth of three of the six test organisms. Additionally, in vivo antifungal activity of dry powdered material from these plants against sorghum covered (Sporisorium sorghi) and loose kernel (Sporisorium cruentum) smuts was screened under field conditions by artificially inoculating separate sets of sorghum seed with smut spores before treating with plant material or two traditionally used fungicides, Thiram 1 and Apron Plus 1 that served as positive controls. Although the incidence of both loose and covered kernel smuts were significantly reduced by material from all plant species, the dry powdered berries of P. dodecandra were most effective. Compared to the untreated control, treatment with the plant material as well as standard fungicides resulted in significant yield increases. It was concluded that a rationale has been established for further investigation into the structured utilization of natural vegetation indigenous to Ethiopia in the agricultural industry.

Antifungal Activity of Essential Oils from Some Medicinal Plants of Iran against Alternaria alternate

“…Although in vitro screening of plant extracts is an important first step in identifying plants with potential application in agriculture, in vivo confirmation of this potential is essential in the search for plant derived preparations with the potential to be commercialized [13] . The ability of five essential oils to inhibit A. alternata was evaluated in vitro contact assays.…”

Antimycotic activities of Cinnamon-derived compounds against Rhizoctonia solani in vitro

“…Indeed, some phytochemicals of plant origin, such as azadirachtin, carvone, and pyrethroids, have already been formulated as botanical pesticides and used successfully in integrated pest management programs (Shmutterer 1990). In addition, the extracts of specific plants are traditionally used as natural fungicides in small scale farming systems in which the use of synthetic chemicals is not economically feasible (Tegegne and Pretorius 2007).…”

“…Such studies have focused on identifying compounds with broad-spectrum activity that could be useful for the treatment of plant diseases and have resulted in the isolation of many antimicrobial compounds (Chu et al 2006;Fiori et al 2000). However, the use of properly developed and scientifically tested plant products for the control of plant diseases is currently limited (Tegegne and Pretorius 2007).…”

Non-chemical Seed Treatment in the Control of Seed-Borne Pathogens

“…Similarly, in field experiments using inoculated seeds, treatment with dried powder from the berries of African soapberry (Phytolacca dodecandra), known to contain saponins, reduced the disease incidence of covered kernel smut (Sporisorium sorghi) (Fig. 8.5) and loose kernel smut (S. cruentum) by 82-92 % (Tegegne and Pretorius 2007). A crude extract from aerial parts of Agapanthus africanus controlled both smuts completely (Tegegne et al 2008).…”