Damping-off and stem rot of cowpea in Benin caused by Sclerotium rolfsii
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.
School:University of Pretoria/Universiteit van Pretoria
School Location:South Africa
Source Type:Master's Thesis
Keywords:phytopathogenic microorganisms damping off diseases cowpea fungal of plants sclerotium rolfsii benin
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