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Published yearly: 

4 Issues


ISSN: 2320-964X (Online) 

ISSN: 2320-7817  (Print)



Dr. Santosh Pawar 


Original Article


Int. Journal of Life Sciences, 2015; 3(4):271-286 |  Available online, December 30, 2015

Assessment of disease intensity and isolates characterization of blast disease (Pyricularia oryzae CAV.) from South West of Ethiopia



Mebratu Gebremariam Asfaha1, Thangavel Selvaraj1*and Getaneh Woldeab2

1Department of Plant Sciences, College of Agriculture and Veterinary Sciences, Ambo University, Ambo, Post Box No: 19, Ethiopia, East Africa.

2Department of Pathology, Ambo Plant Protection Research Center (APPRC), Ambo, Ethiopia, East Africa. 

*Corresponding author:  Email: Mobile Number: +251-913073294.

Received: 23.10.2015  |  Revised: 20.11.2015   |  Accepted: 06.12.2015  | Published : 30.12.2015

Blast (Pyricularia oryzae Cav.) disease is one of the most important biotic constraints to rice production in South West of Ethiopia. The present study was conducted to determine the intensity of the blast disease and their isolates characterization in upland rice cultivated fields of South West of SNNPRS of Ethiopia. The assessment of rice blast was carried out in 90 farmers’ fields in three districts during the main cropping season from May to October 2013, in the major upland rice growing areas of Kaffa, Benchi-Maji and Sheka zones in South West of Ethiopia. The results of the assessment revealed that the incidence and severity of the disease vary from low to high on the rice fields depending on the agro-ecological and cultivars differences. Rice blast was observed in all assessed locations at variable levels. The incidence of rice blast in six different localities varied from 42.01 to 85.69%. The highest mean incidence of rice blast was recorded in Otuwa locality (85.69%) and the lowest incidence recorded in Argoba locality (42.01%). The overall mean incidence of six localities in three districts of the South west of Ethiopia (SNNPRS) reached 65.68%. Likewise, blast severity showed similar trend as that of incidence in all six localities. The highest severity was recorded in Otuwa locality with range of 8.88 - 88.8 % and the mean severity values of 55.7% while the lowest severity was recorded in Argoba locality (33.62%). The overall mean severity of the six localities in three districts of the South west SNNPRS reached 47.15%. The entire assessed three districts showed 100 % blast disease prevalence. Rice blast, Po isolates were characterized and identified based on their growth parameters into six isolates such as Po12, Po28, Po41, Po55, Po72 and Po85. Among the four culture media (oat meal agar, rice flour agar, malt extract agar and potato dextrose agar), the Po isolates were grown on optimum growth and good sporulation in oat meal agar followed by rice flour agar. The optimum temperature and pH of the growth of the Po isolates were at 30oC and 6.5, in almost all isolates, respectively. It could be concluded that the rice blast was the most important disease of rice cultivars in South West (SNNPRS) of Ethiopia. Further studies could be conducted to evaluate the upland rice cultivars resistance against the isolated blast (Po isolates) pathogens under greenhouse and natural environmental conditions.


Key words: Rice, blast, Pyricularia oryzae, Assessment, Disease Intensity, Po isolates, Characterization.


Editor: Dr. Arvind Chavhan


Cite this article as:

Mebratu Gebremariam Asfaha, Thangavel Selvaraj and Getaneh Woldeab (2015) Assessment of disease intensity and isolates characterization of blast disease (Pyricularia oryzae CAV.) from South West of Ethiopia. International J. of Life Sciences, 3(4): 271-286.


Copyright: © 2015 | Author(s), This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial - No Derivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.


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