Vol. 8, Issue 4, Part i (2024)

Abstract: Ginger (Zingiber officinale Rosc.) is a perennial monocotyledonous herb belonging to the the family Zingiberaceae. The leaf spot disease in ginger caused by Phyllosticta zingiberi Ramakr. Occur in mild to severe form in all ginger growing areas of Karnataka. Investigation was carried out to study the cultural and physiological characteristics of the pathogen. Among different solid media tested, maximum mycelial growth was recorded on Potato dextrose agar and Richard’s agar followed by Sabouraud’s dextrose agar. Among the different temperature regime tested, maximum mean mycelial growth of 90.00 mm was observed at 30 °C followed by 25 °C (84.70 mm). When exposed to different light regimes, the highest mean mycelial growth of 88.10 mm was recorded when the isolates were exposed to alternate cycles of 12 hours light and 12 hours dark followed by complete dark (85.50 mm). Highest mean mycelial growth of the pathogen was recorded at pH 4.00 (86.30 mm) followed by pH 5.00 (86.00 mm). Further, maximum mean mycelial growth was recorded in media containing dextrose (83.76 mm) followed by mannitol (82.66 mm) and sucrose (76.06 mm). Highest mean mycelial growth of 90.00 mm was recorded in potassium nitrate followed by sodium nitrate (89.34 mm) and ammonium molybdate (78.16 mm) was recorded from among the different nitrogen source.