In vitro evaluation of the phytopharmaceutical potential of aqueous extracts of Jatropha curcas seeds, Thevetia peruviana seeds and Cyperus rotundus rhizomes against Phytophthora infestans (Mont) de Bary

Abstract

The aim of the present study was to evaluate in vitro, the phytopharmaceutical potential of aqueous extracts of Jatropha curcas seeds, Thevetia peruviana seeds and Cyperus rotundus rhizomes on Phytophthora infestans, a plant pathogen responsible for downy mildew. To this end, the phytopharmaceutical potential was evaluated using several doses of extracts (0, 5, 15 and 25 mg/ml) on PDA medium. 5 mg/ml of chemical fungicide active substance, Mancozeb™ 800 g/kg, was used as a positive control. Rationally, the aqueous extract of T. peruviana seeds (3.08; 65.44 mg/m l), then of J. curcas (2.89; 142.93 mg/ml) due to their minimum predicted doses inhibiting the growth of said phytopathogen (MDI50; MDI90), were more effective compared to the extract of C. rotundus rhizomes (21.91; 296.67 mg/ml). Aqueous extracts of T. peruviana and J. curcas seeds thus represent a promising alternative for biological control of mildew.