Antifungal Activity of Some Inorganic Salts on the Development of Fusarium spp., Causal Agents of Potato Tuber Dry Rot

Potato dry rot caused by Fusarium spp. is one of the main fungal diseases hampering the production and marketing of potato tubers in Cameroon. This study was carried out in order to improve the health status of potato tubers and their preservation. To achieve this objective, Fusarium spp. were isolated on the Potato Dextrose Agar (PDA) culture medium and identified on the basis of morphological and microscopic characteristics using reference documents. Antifungal activity of six inorganic salts was evaluated in vitro on the development of Fusarium spp. and on potato tubers artificially infected with these fungal species. The results showed that all the inorganic salts had a depressant effect on the development of Fusarium spp. Copper sulfate inhibited at 100%, the radial growth and sporulation of Fusarium spp. at all concentrations. Sodium metabisulfite and sodium carbonate inhibited at 100%, the growth and sporulation of all fungal species from a concentration of 6.4 mg/ml. No lesions were observed on inoculated potato tubers when they were treated with copper sulfate. These results suggest the implementation of a strategy to control dry rot of potato tubers through the use of inorganic salts, in order to reduce the losses caused by Fusarium spp.