Browsing by Author "SUPRITHA, R."
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ThesisItem Open Access STUDIES ON UDBATTA DISEASE IN RICE (Oryza sativa L.) CAUSED BY Ephelis oryzae Syd.(Keladi Shivappa Nayaka University Agricultural and Horticultural Science (COA,Shivamogga), 2023-12-02) SUPRITHA, R.; Dr. G. N. HOSAGOUDAR; Dr. SURESHA D EKABOTERice (Oryza sativa L.) is one of the important cereal crop belonging to the family Poaceae. Among the significant diseases affecting rice, the Udbatta disease of paddy caused by Ephelis oryzae is on the rise. The present study was carried out with an aim to survey, isolation, identification and proving the pathogenicity; cultural, morphological and physiological characterization; the in-vitro evaluation of fungicides; in vitro evaluation of seed treatment with fungicides in roll towel method against E. oryzae. A roving survey was carried out in Shivamogga, Kodagu and Chikkamagaluru districts of Karnataka revealed the highest PDI was recorded in Kodagu (11.76 %), followed by Shivamogga (10.98 %). Cultural studies showed that the Potato dextrose agar (35.20 mm) and Sabouraud’s agar (32.85 mm) supported maximum growth of mycelia of the pathogen, whereas the colony was found to be flat and raised to fluffy with waxy and leathery texture. The conidia are needle-shaped, hyaline and aseptate, measuring about 18.0 - 25 µm x 1.0 - 1.9 µm. Physiological studies revealed that the highest dry mycelial weight of the pathogen was recorded at a temperature of 25 °C (41.55 mg) and pH 7.0 (49.78 mg). In vitro studies indicated that, among the contact fungicides evaluated, Copper oxychloride 50 % WP was found to be effective with mean mycelial inhibition of 62.59 per cent. Among systemic and combi product fungicides evaluated, Tebuconazole 45% SC and Carbendazim 12 % + Mancozeb 63 % WP showed a cent per cent mean mycelial inhibition respectively. Among the fungicides tested in the roll towel method, the least mean per cent seed infection (1.00 %), high mean per cent germination (99.00 %) and seedling vigour index of 1967.46 was recorded when seeds treated with Carbendazim 12 % + Mancozeb 63 % WP.