OCCURRENCE AND IDENTIFICATION OF DIEBACK FUNGAL PATHOGENS OF JATROPHA CURCAS IN SELECTED PLANTATIONS IN NORTH-WEST NIGERIA.

Abstract

Jatropha curcas L. (Physic nut) is a drought-tolerant plant used in erosion control, biofuel production, and curing ailments traditionally. Fungal diseases were some of the prevalent diseases recorded on the plant in Nigeria and thus, a survey to determine the incidence, severity and causal organisms of dieback on Jatropha was conducted on three farms at Tsanni (Katsina State), Minjibir (Kano State), and Samaru (Kaduna State). Five quadrants measuring 6 X 6 m2 were marked per hectare randomly and plants within each quadrant were used to assess disease incidence and severity. Three fungi isolated from collected diseased samples were identified by CABI, London as Fusarium clade VII, Fusarium solani, and Gibberella fujikuroi. These fungal organisms were confirmed as the causal organisms for Jatropha dieback at the three locations upon Koch’s postulation. The disease incidence and severity at Samaru, Tsanni, and Minjibir were 100 and 34.0; 78.1 and 24.9; and 31.3 and 22.7 %, respectively. Therefore, it was concluded that Jatropha dieback which is associated with Fusarium species and its anamorph Gibberella fujikuroi was most prevalent in Samaru.