Effects of Soil Chemical Characteristics on the Occurrence of Entomopathogenic Nematodes
Fanuel Kawaka *
Department of Pure and Applied Science, Technical University of Mombasa, P.O Box 90420, Mombasa, Kenya
John Kimenju
College of Agriculture and Veterinary Science, University of Nairobi, P. O. Box 30197, Nairobi, Kenya
Sheila A. Okoth
College of Biological Sciences, University of Nairobi, P.O. Box 30197, Nairobi, Kenya.
George Ayodo
Center for Global Health and Child Development-Kenya (CGHCD-Kenya), P.O. Box 130, Kisumu, Kenya
Shelmith Mwaniki
National Agricultural Research Laboratories, KARI, P.O. Box 14733, Nairobi, Kenya
John Muoma
Department of Biological Sciences, MMUST, P.O. Box 190, Kakamega, Kenya
George Orinda
Department of Biochemistry and Biotechnology, Kenyatta University, P.O Box 43844, Nairobi, Kenya
*Author to whom correspondence should be addressed.
Abstract
Aims: This study was conducted to determine the effect of selected soil chemical characteristics on the occurrence of entomopathogenic nematodes (EPNs) under different land uses in Embu and Taita Districts in Kenya.
Study Design: The sampling points were systematically marked in a grid-mesh construction using GPS marking.
Place and Duration of Study: Soil sampling was done between January 2008 and May 2008 in Embu district in the highlands of Central and Taita-Taveta district in the Coastal highlands of Kenya.
Methodology: EPNs were baited from soil using Galleria mellonella larvae and infective juveniles identified using morphological- biometric characteristics. The nematode occurrence was evaluated through relative abundance and recovery frequency expressed as percentage from the soils.
Results: EPNs were detected in 43.3% of the samples with Steinernema spp being the dominant species. The occurrence of EPNs is affected by selected soil chemical properties, land use systems and heavy metals.
Conclusion: Soil fertility management practices and heavy metals influence the occurrence of EPNs and should be considered for their effective use as biological control agents.
Keywords: Steinernema, abundance, infective-juveniles, frequency, fertility