PHYSIOCHEMICAL AND PATHOLOGICAL STUDIES OF MANGO MALFORMATION IN SAURASHTRA REGION
KrishiKosh
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Title |
PHYSIOCHEMICAL AND PATHOLOGICAL STUDIES OF MANGO MALFORMATION IN SAURASHTRA REGION
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Creator |
AMIPARA JYOTIBEN DURLABHBHAI
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Contributor |
Parakhia A.M.
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Subject |
Mango
Plant Pathology |
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Description |
Mango (Mangifera indica L.) is an important fruit crop of India and other subtropical and tropical countries of the world. Among all the fruit crops grown in India, mango occupies a predominant position. The crop was found to suffer from floral and vegetative malformation caused by Fusarium spp. assumes greater significance as this disease is found to occur since last five year and became epidemic during flowering season and damaged 60 to 80 per cent plant population in mango orchards in Saurashtra region of Gujarat state. The symptoms consist of excessive vegetative branches with limited growth and very short internodes in affected seedlings. Apex shoot and axillary buds were misshapen and produced shortened internodes with dwarfed and narrow leaves. The affected inflorescence produced compact mass of male flowers with greater size and number, greenish in color and stunted in growth. Such panicles did not bear fruit or abort fruit shortly before attaining the pea size. Isolation from diseased plant parts yielded the species of Fusarium. Based on morphological characteristics, fungus was identified as Fusarium moniliforme var. subglutinans Wollenw and Reink (ITCC No.6472.07) and Fusarium oxysporum(ITCC No. 6471.07) and confirmed at IARI, New Delhi. Incision method was highly effective to prove pathogenic nature of both the fungi. The incidence of mango malformation reached the peak in February due to combination of optimum ambient temperature, high relative humidity and wind speed. Out of fifteen mango cultivars, none showed immune reaction to malformation. The Ashadhio a local cultivar was comparatively tolerant and cv. kesar showed highly susceptible reaction to Fusarium spp. During the survey, severity of disease was ranged from 5 to 72 per cent. It was maximum (floral 24 to 72%, vegetative 15 to 50%) in Junagadh taluka followed Talala taluka. All carbohydrates fractions, total carbohydrate, total nitrogen and total protein contents were increased during vegetative and floral malformation stage of disease but phenol was reduced. The mango >15 year age was responded well to protective application of carbendazim 50 WP + mancozeb 75 WP (1:2) @ 3 g/l in term of suppression of disease and the maximum average avoidable yield loss of 32.34 per cent was observed in 15 year old tree followed by >15. Soil Fe, Cu, Zn and Co3- content of water were significant and negatively (r = -0.84. r= -0.69, r= -0.44 and r= -0.42) correlated with per cent disease intensity. The MRA equation Y = 37.35 -0.89X3** - 2.82X6**+ 1.00X12 ** = 0.78 can be applied for prediction of malformation incidence. The Fe content of soil (X3) along with Cu content of soil(X6) and Ca of irrigation water (X12) were the most deciding factors for development of malformation. In vitro, T. harzianum -IV elicited strong antagonism against F. moniliforme var. subglutinans (77.78 %) and F. oxysporum (74.44%) closely followed by T. virens. The bacterial antagonist fluorescent pseudomonad was significantly superior to inhibit the both fungi. Systemic fungicides, carbendazim, thiophanate methyl, propiconazole, and difenconazole gave cent per cent inhibition of both fungi even at minimum concentration of 50 ppm. In non-systemic fungicides, thiram was superior for inhibition of F. moniliforme var. subglutinans and copper oxychloride for F. oxysporum at 1000 ppm. Carbendazim 12 WP +mancozeb 63 WP (Saff), iprodine 25 WP + carbendazim 25 WP (Quintal), carbendazim 50 WP + mancozeb 75 WP 1:2, carbendazim 50 WP + thiram 75 WP, 1:2 and carbendazim 50 WP + copp. oxy. 50 WP, 1:2 gave complete inhibition of both fungi even at lower concentration of 500 ppm. The systemic insecticides were poor in inhibiting both fungi except dimethoate, which gave 77.78 per cent inhibition of F. oxysporum at 500 ppm whereas non-systemic insecticides were better for inhibiting the growth at 3000 ppm concentration except ethion 50 EC. The presence of Trichoderma spp. in soils of mango orchards had positive effect on malformation intensity. Soil application of T. harzianum-IV showed maximum control (floral 60.08 % and vegetative 42.99%) of disease followed by T. virens. The field performance of carbendazim (0.05%) was remarkable, and proved the best in controlling (floral 75.51 % and vegetative 73.62 %) the disease followed by thiophanate methyl (0.05%). The foliar application of carbendazim 50 WP + mancozeb 75 WP (0.3%) gave maximum control (floral 70.92 % and vegetative 65.56 %) of disease closely followed by carbendazim 50 WP + thiram 75 WP. |
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Date |
2016-09-19T16:41:10Z
2016-09-19T16:41:10Z 2008-02 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/77505
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Language |
en
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Format |
application/pdf
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