Effectiveness of plant extracts on suppression of damping-off and wilt diseases of lupine (Lupinus termis Forsik)

The aim of this study was to evaluate water and organic solvent of plant extracts for protection of lupine plants against damping-off and wilt diseases caused by Fusarium oxysporum f. sp. lupini, F. oxysporum f. sp. lupini Snyder & Hansen was isolated from diseased lupine roots collected from different locations of Minia, Assiut and New Valley governorates. Water leaf extracts of Calotropis procera, Nerium oleander, Eugenia jambolana, Citrullus colocynthis, Ambrosia maritime, Acacia nilotica and Ocimum basilicum and fruit extracts of C. colocynthis, C. procera and E. jambolana reduced damping-off and wilt diseases caused by F. oxysporum f. sp. lupini. Water extracts of E. jambolana leaves, C. colocynthis fruits and N. oleander leaves were the most effective ones for controlling such diseases. In contrast, A. nilotica and O. basilicum extracts were the least effective ones. Organic solvent extracts of tested plants reduced damping-off and wilt diseases than water extracts. Butanolic and ethereal extracts were highly effective in reduction of diseases than the other tested extracts. Under field conditions, during winter growing seasons 2008/09 and 2009/10, ethereal and butanolic extracts of N. oleander and E. jambolana leaves and C. colocynthis fruits significantly reduced the percentage of wilt severity as well as improved growth parameters (plant height, number of branches, pods and seeds per plant) and increased seed index, total seed yield/hectare compared with control treatment, while protein content in seeds was not effected. In conclusion, our study demonstrated that some plant extracts can be used for biocontrol of lupine damping-off and wilt diseases.

Research highlights
► Lupine seed soaked in extracts of Calotropis procera, Nerium oleander, Eugenia jambolana, Citrullus colocynthis, Ambrosia maritime, Acacia nilotica, and Ocimum basilicum significantly decreased damping-off and wilt diseases.
► The organic solvent extracts of N. oleander leaves, E. jambolana leaves and C. colocynthis fruits caused higher effect than water extracts in controlling such diseases.
► Under field conditions, ethereal and butanolic extracts of N. oleander leaves, E. jambolana leaves and C. colocynthis fruits have significantly reduced the percentage of wilt severity as well as improved growth parameters (plant height, number of branches, pods and seeds per plant) and increased seed index, total seed yield/hectare compared with control treatment.