The damping-off and stem rot disease syndrome is harmful to many cultivated crops. Damping-off and stem rot caused by Sclerotium rolfsii Sacc. on cowpea results in yield losses with serious socio-economic implications. The objectives of the present study were to investigate the occurrence of the diseases in Benin, study etiology and factors influencing the diseases, and develop strategies for the control of the diseases in the field. Results showed that the diseases are distributed countrywide. Sclerotium rolfsii was the main causal agent but minor pathogens, namely Pythium sp., Rhizoctonia solani Kühn and Phoma pomorum Thüm were also recorded. In the Ouémé valley, the diseases were favoured by soil moisture and S. rolfsii initial inoculum that were higher closer to the river. Sclerotium rolfsii isolates collected in the valley showed genetic diversity in terms of pathogenicity, mycelial compatibility groups and ITS rDNA sequences. A paper-based screening method was found to be a rapid laboratory method for screening for resistance in cowpea cultivars. Furtheremore, Moringa oleifera L. leaf extracts, Trichoderma Kd 63 and Trichoderma IITA 508 significantly reduced the disease incidence. The best disease control was recorded in the field when M. oleifera seed treatment was integrated with a soil sprinkle of Trichoderma. The present work provides information on damping-off and stem rot of cowpea in Benin and control strategies for ecologically sustainable cowpea production. / Thesis (DPhil (Microbiology and Plant Pathology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/23192 |
| Date | 14 January 2005 |
| Creators | Adandonon, Appolinaire |
| Contributors | Dr M Tamo, Prof T A S Aveling, upetd@up.ac.za |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | © 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria |
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