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20012
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Subject: Plant Pathology × Author: Devaraju, K × Start date: 1961 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    STUDIES ON Colletotrichum gloeosporioides (Penz.) Penz and Sacc. THE CAUSAL AGENT OF LEAF SPOT OF CASHEW (Anacardium occidentale L.)
    (University of Agricultural Science, Dharwad, 2001) Devaraju, K; Naik, K S
    "Studies on Colletotrichum gloeosporioides a causal agent of leaf spot of cashew (Anacardium occidentale L.) includes sun-ey of the disease spread, morphological, physiological, nutritional studies, spore germination, toxin studies, host range studies and in vitro evaluation of chemicals and botanicals. During survey in three districts the maximum mean per cent disease index was found to be 17.10 in Sirsi. The fungus was isolated from infected cashew leaves. The pathogenicity was proved by spraying monoconidial culture which resulted in the formation of numerous oval or irregular brown or deep brown spots of variable sizes and shapes were noticed. The conidia were cylindrical or oblong, hyaline single celled with oil globules in the centre and measured about 8.2 to 10.34 x 3.4 x 4.5 ;Um. Spores germinated with varied number of germtubes originated from any surface of the conidia. Among various media tested maximum spore germination occurred in two per cent sucrose solution. Potato dextrose agar and Richards's broth were best solid and liquid media respectively which supported maximum growth of the fungus. Sucrose, potassium nitrate and magnesium sulphate yielded maximum dry mycelial weight of the pathogen among the carbon, nitrogen and sulphur sources respectively. Maximum growth of fungus was recorded at 6.5 pH and 30°C temperature. Maximum toxic metabolite was produced when sucrose, potassium nitrate and magnesium sulphate were used as carbon, nitrogen and sulphur sources, respectively. The pathogen showed positive reaction on all the host tested. In vitro evaluation of fungicides and botanicals revealed that carbendazium (500, 1000 and 1500 ppm) and garlic bulb extract (5 and 10%) were effective against C. gloeosporioides respectively. Among different cultivars tested, Vengurla-1 showed resistant reaction for leaf spot of cashew under artificial condition."
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    ThesisItemOpen Access
    STUDIES ON Colletotrichum gloeosporioides (Penz.) Penz and Sacc. THE CAUSAL AGENT OF LEAF SPOT OF CASHEW (Anacardium occidentale L.)
    (University of Agricultural Science, Dharwad, 2001) Devaraju, K; Naik, K S
    "Studies on Colletotrichum gloeosporioides a causal agent of leaf spot of cashew (Anacardium occidentale L.) includes sun-ey of the disease spread, morphological, physiological, nutritional studies, spore germination, toxin studies, host range studies and in vitro evaluation of chemicals and botanicals. During survey in three districts the maximum mean per cent disease index was found to be 17.10 in Sirsi. The fungus was isolated from infected cashew leaves. The pathogenicity was proved by spraying monoconidial culture which resulted in the formation of numerous oval or irregular brown or deep brown spots of variable sizes and shapes were noticed. The conidia were cylindrical or oblong, hyaline single celled with oil globules in the centre and measured about 8.2 to 10.34 x 3.4 x 4.5 ;Um. Spores germinated with varied number of germtubes originated from any surface of the conidia. Among various media tested maximum spore germination occurred in two per cent sucrose solution. Potato dextrose agar and Richards's broth were best solid and liquid media respectively which supported maximum growth of the fungus. Sucrose, potassium nitrate and magnesium sulphate yielded maximum dry mycelial weight of the pathogen among the carbon, nitrogen and sulphur sources respectively. Maximum growth of fungus was recorded at 6.5 pH and 30°C temperature. Maximum toxic metabolite was produced when sucrose, potassium nitrate and magnesium sulphate were used as carbon, nitrogen and sulphur sources, respectively. The pathogen showed positive reaction on all the host tested. In vitro evaluation of fungicides and botanicals revealed that carbendazium (500, 1000 and 1500 ppm) and garlic bulb extract (5 and 10%) were effective against C. gloeosporioides respectively. Among different cultivars tested, Vengurla-1 showed resistant reaction for leaf spot of cashew under artificial condition."