Field evaluation of six cassava genotypes for resistance to root rot disease was compared with three rapid laboratory methods (whole root inoculation, root slice inoculation, and stem inoculation) for resistance screening. Both the field evaluation and the three laboratory methods separated the v...
Onyeka, T.J.
,
Dixon, A.
,
Ekpo, E.J.
,
[Assessment of laboratory methods for evaluating cassava genotypes for resistance to root rot disease]
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Assessment of laboratory methods for evaluating cassava genotypes for resistance to root rot disease
eports of cassava root rot disease from different African countries have increased in recent times. Field studies were conducted from July 1998 to October 1999 to determine a reproducible disease assessment method that would allow the comparison of results from different locations and an evaluati...
Onyeka, T.J.
,
Dixon, Alfred G.O.
,
Ekpo, E.J.A.
,
[Field evaluation of root rot disease and relationship between disease severity and yield in cassava]
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Field evaluation of root rot disease and relationship between disease severity and yield in cassava
Anthracnose and virus diseases exert devastating impacts on yam production in many tropical regions of the world where the crop contributes to food security and income generation. The complexities in their epidemiology necessitate the use of integrated approaches in their management. Six genotype...
Egesi, Chiedozie N.
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Onyeka, T.J.
,
Asiedu, Robert
,
[Severity of anthracnose and virus diseases of water yam (dioscorea alata L.) in NIgeria I: effects of yam genotype and date of planting]
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Severity of anthracnose and virus diseases of water yam (dioscorea alata L.) in NIgeria I: effects of yam genotype and date of planting
Geo-referenced surveys were conducted in 2001 and 2003 to assess the prevalence and severity of
cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) in different agro-ecological
zones of Nigeria. A total of 132 fields were visited in 2001 as follow: humid forest (HF) 42, derived
s...
Onyeka, T.J.
,
Owolade, O.F.
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Ogunjobi, A.A.
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Dixon, Alfred G.O.
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Okechukwu, R.U.
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Bamkefa, B.
,
[Prevalence and severity of bacterial blight and anthracnose diseases of cassava in different agroecological zones of Nigeria]
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Prevalence and severity of bacterial blight and anthracnose diseases of cassava in different agroecological zones of Nigeria
Anthracnose, caused by Colletotrichum gloeosporioides, is one of the major constraints limiting water yam (Dioscorea alata) production in the tropics. In this region, yam anthracnose control is mostly achieved by the deployment of moderately resistant yam genotypes. Therefore, screening for new s...
Nwadili, C.O.
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Augusto, J.
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Bhattacharjee, R.
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Atehnkeng, J.
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López Montes, A.
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Onyeka, T.J.
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Kumar, P.L.
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Asiedu, Robert
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Bandyopadhyay, Ranajit
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[Comparative reliability of screening parameters for anthracnose resistance in water yam (Dioscorea alata)]
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Comparative reliability of screening parameters for anthracnose resistance in water yam (Dioscorea alata)
Yam anthracnose and virus diseases are the most important biotic constraints affecting yam production in the world. Six Dioscorea alata genotypes were evaluated for their reaction to these diseases in four distinct agro-ecological zones in Nigeria for two years. Data obtained were subjected to li...
Egesi, Chiedozie N.
,
Onyeka, T.J.
,
Asiedu, Robert
,
[Environmental stability of resistance to anthracnose and virus diseases of water yam (Dioscorea alata)]
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Environmental stability of resistance to anthracnose and virus diseases of water yam (Dioscorea alata)
Onyeka, T.J.
,
Dixon, Alfred G.O.
,
Bandyopadhy, R.
,
Okechukwu, R.U.
,
Bamkefa, B.
,
[Survey of the distribution and current status of bacterial blight and fungal diseases of cassava in Nigeria]
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Survey of the distribution and current status of bacterial blight and fungal diseases of cassava in Nigeria