Abstract:
Potato is one of the most important crops and staple food of many cultures and civilizations past and present. Fusarium dry rot is one of the most important diseases of potato worldwide, affecting tubers in storage and seed pieces after planting causing losses up to 60%. Considering the irrational use of synthetic pesticides to control various pests and pathogenic microorganisms of crops plants and their adverse effects on environment, natural habitats through their residual toxicity, this study was conducted under laboratory conditions at Plant pathology Department, College of Agricultural Studies “Shambat”, Sudan University of Science and Technology, to investigate the bioactivity of aqueous extracts of Garlic fruits, Ginger roots and efficacy of Fungicide (Revus Top) against fungal growth of Fusarium solani, the causal agent of dry rot of potato . Three concentrations of aqueous extract of Garlic and Ginger, each of 25%, 50% and 100%, and fungicide at three concentrations, 25%, 50%, and 100% were used in addition to control. The assessment of their inhibitory effect against the fungus was recorded through the percentage of fungal growth inhibition. The results revealed that all concentrations of the aqueous extracts of Garlic and Ginger and Fungicide exhibited significantly high inhibitory effect ranging from 49.3% to 100% against the linear growth of test fungus compared to control. The highest concentration of Garlic extract (100%), Ginger (100%) and the Fungicide (100%), gave significantly higher inhibition zones percent (88.6%, 78.9% and 90.0%) respectively compared to the untreated control in day six after inoculation. Among the plant extracts tested that of Garlic at all concentration (25%, 50% and 100%) was generally the most effective in suppressing the fungus growth( 44.4%, 64.4% and 91.0%) than its equivalent Ginger (44.5%, 60.0% and 85.6%) respectively. Moreover, concentration of each aqueous extract as well as that of fungicide reacted differently against test fungus. Generally, the results showed that the antifungal activity increasing with increase in extract concentration and time . Obviously, the test fungus differs in its response to the different concentrations but on the whole, growth inhibition increased with increased concentration. The current results were considered promising and encouraging to use bicarbonates salt for plant disease control.
