STUDIES ON COCONUT LEAF DISEASES IN ORISSA AND THEIR MANAGEMENT
KrishiKosh
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Title |
STUDIES ON COCONUT LEAF DISEASES IN ORISSA AND THEIR MANAGEMENT
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Creator |
Ghose, Sugata
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Contributor |
Mishra, Budhadev
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Subject |
coconut leaf disease, management
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Description |
Coconut (Cocos nucifera Linn) is a versatile palm and a major plantation crop of Orissa. Coconut crop in Orissa was severely damaged during 1999 in devastating super cyclone During post cyclone years, the coconut situation of Orissa slowly improved, but one of the major reasons for low productivity was damage caused by various coconut diseases. Considering limited information available, the present study on leaf diseases of coconut in Orissa with special emphasis on grey leaf blight was conducted. A disease survey was conducted in five major coconut growing districts of Orissa. Eight coconut leaf diseases were found during the survey. Out of which grey leaf blight (GLB) caused by Pestalotiopsis palmarum was found to occur most frequently. During the survey GLB was found in all the 21 locations with max. PDI 47.2 % at Sakhigopal, Puri. All the eight pathogens were identified and their pathogenesity was confirmed. Identity of four cultures was confirmed by IARI, New Delhi. Identified eight pathogens causing coconut leaf diseases were as follows. grey leaf blight (Pestalotiopsis palmarum), black spot (Alternaria alternate), leaf necrosis (Fusarium pallidoroseum), brown blight (Colletotrichum gloeosprioides), linear leaf spot (Curvularia lunata), tip burn (Helminthosporium halodes), orange blight (Acreminium zeylanicum)I and angular blight (Phoma palmarum).Acreminium zeylanicum causing Orange Leaf Blight on Coconut leaves was a new report on coconut. Seasonal variation in occurrence of GLB was distinct. PDI was maximum in June and gradually went down till January. Thereafter slowly increased again till March and went down to minimum in May. Against GLB, tall coconuts were found to be more tolerant than dwarfs. Out of the eight varieties tested Tiptur Tall was most tolerant and Chowghat Orange Dwarf was most susceptible. Among dwarfs Malayan group was more tolerant than Chowghat group. Correlation of eight weather parameters with occurrence of GLB was studied. GLB occurrence was found to be positively correlated with minimum temperature, total rainfall, number of rainy days, afternoon relative humidity and negatively correlated with sunshine hour. On analysis of nutrient content of leaves it was found that in diseased leaves N, P and K content were less than healthy leaves. In diseased leaves Ca and Na were more and Mg and S were less. Moisture content of diseased leaves was less than the healthy leaves. Turmeric powder was found to be most effective followed by Neem leaf extract in in vitro study of GLB management with six plant extracts. Among six fungicides Topsin – M and Bavistin were found to inhibit mycelium growth by 100 %. Management of five coconut leaf diseases with six plant extracts at 20 % concentrate was studied in vitro. Tulsi was found most effective against brown blight, Neem against angular blight & black spot and Lantana against linier leaf spot and leaf necrosis. Management of five coconut leaf diseases with six fungicides at 200 ppm concentrate was studied in vitro. Tilt-250 (Propiconazole) was found to inhibit mycilial growth of all the five pathogens by 100 %. Bavistin (carbendazim) also recorded 100 % inhibition of mycilial growth against angular blight. |
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Date |
2017-01-03T14:19:49Z
2017-01-03T14:19:49Z 2014 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/94157
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Language |
en
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Relation |
Th;4305
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Format |
application/pdf
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