Vol. 7, Issue 9, Part L (2025)

Lentil (Lens culinaris Medik) is a major pulse crop in India, but its productivity is severely threatened by Fusarium wilt caused by Fusarium oxysporum f. sp. lentis. A field survey conducted during the Rabi season of 2024-25 in Satna district, Madhya Pradesh, revealed wilt incidence across different growth stages of lentil, with symptoms including stunted growth, chlorosis, vascular discoloration, and complete plant collapse in severe cases. Symptomatic plants were collected, and the pathogen was isolated, purified through single spore technique, and identified based on cultural and morphological characteristics. On PDA medium, colonies appeared initially white and fluffy, later turning pinkish-violet, with abundant aerial mycelium. Microscopy showed hyaline, septate, branched hyphae; unicellular oval to rod-shaped microconidia; slightly curved 3-4 septate macroconidia; and thick-walled chlamydospores borne terminally or intercalarily. Physicochemical studies revealed that PDA supported maximum radial growth, followed by CMA, while SDA was least favorable. Temperature assays showed optimum growth at 25 °C, with reduced growth at 10-15 °C and 30-35 °C. pH studies indicated that neutral to slightly alkaline conditions were most suitable, with highest growth at pH 8.0, while acidic pH levels (5.0-6.0) restricted growth. These findings confirm that Fusarium oxysporum f. sp. lentis best on PDA medium, at 25 °C, and under neutral to slightly alkaline conditions.