STUDIES ON BACTERIAL LEAF BLIGHT OF RICE CAUSED BY Xanthomonas campestris pv oryzae (Uyeda and lshiyama, Dowson) Dye
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Title |
STUDIES ON BACTERIAL LEAF BLIGHT OF RICE CAUSED BY Xanthomonas campestris pv oryzae (Uyeda and lshiyama, Dowson) Dye
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Creator |
JAYASIMHA REDDY, M
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Contributor |
RAMACHANDRA REDDY, A.G
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Subject |
STUDIES, BACTERIAL, LEAF, BLIGHT, RICE, CAUSED, Xanthomonas, campestris,
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Description |
Bacterial leaf blight of rice caused by Xanthomonas campestris pv oryzae (Uyeda and Ishiyama, Dawson) Dye. is a severe disease on high yielding rice cultivars. Symptom!? appeared as water soaked lesions from the - cut ends of leaves after two days of lnocul1ation. The lesions extended on both the sides of leaves and turned orange yellow. A.f ter 14 Elays of inoculation the lesions extended and tne ..leaves turned to yellowis.h white. A characteristic wavy margin was observed . between the healthy and diseased leaf~ portions • Among the 52 rice c~ (h\IQYS screened against BLB, 5 cul ti vars showed resistant reaction, while 20 cultivars were moderately res is t,au t, 19 cu 1 t, l vars we rc modt!t'a Lc ly au:w f:- ptible and the r emaining 8 cultivars were highly susceptible. Rate of spread of the disease was studied in BJ 1 , IR 20 and T { N) 1 , which indica ted that in ·esistant BJ 1 the spread of the pathogen was very much . restricted and in suscept~bl~ T{N) 1 ·The pathogen could spread to a longer lear area~ These 52 rice cultiv~rs were'~n~ooui~ted at three different ages of crop ·growth in order to study the effect of crop age on disease incidence. Varieties BJ 1 and DV 85 showed resistant reaction at all the three stages or inoculation, while IR 62 showed resistance at 30 days after sowing and MTU 6861 and _Wgl 22245 sh~wed resistance at . . .60 days a.f..t er sowing and remaining ~. arieties developed resistance with plant age. Studies on changes in biochemical constituents of susceptible and resistant varieties following BLB infection indicated that healthy leaves of BJ 1 and IR 20 contained more sugars than healthy leaves. of RNR 1446 and T{N)1. The level of total sugars decreased in diseased leaves of all the 4 varieties but the decrease was more in T(N)1 and RNR 1446. Amino acids were more in highly susceptible and suceptible varieties than in resistant and moderately resistant varieties. The amino acid content was · increased in diseased leaves of T(N)1 and RNR 1446 but decreased in BJ 1 and IR 20.phenolsand The increase in OD phenols and total was more aft.cr inoculation in BJ 1, IRto RNR 1446 and least in T(N)1. Healthy l eaves of resistant varieties had more quant.itles of OD phenols and total phenols than the susceptible varieties. Slow releasing nitrogenous fertilizers showed a marked effect on severity of BLB on T ( N) 1. Among the three slow releasing nitrogenous fertilizers urea super granules had a considerable effect which not only increased disease score, plant height but also number of tillers. A combination of N, P and K showed a good effect on T(N) 1, with a least disease score, proper plant height and number of tillers when compared to individual treatments of N, P and K. |
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Date |
2016-08-05T10:23:36Z
2016-08-05T10:23:36Z 1988 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/70991
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Language |
en
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Relation |
D3019;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD
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