Host status of twelve commonly cultivated crops in the Cameroon Highlands for the nematode Pratylenchus goodeyi

Abstract

Pratylenchus goodeyi is a recognized pest of bananas and plantains in African highland regions. To evaluate the crop host status of P. goodeyi in the Cameroon Highlands, a field experiment was conducted in a field previously cropped with banana, using 12 crops planted in a randomized design with four replicates. The site was at Mbouroukou near Melong at 1200 m above sea level on volcanic soils. Banana was the susceptible reference crop. Sampling of roots and rhizosphere soil was undertaken at 4 months after planting. A non-parametric ANOVA revealed significant differences in P. goodeyi root population densities among the treatments (crops). Crops were classified as good hosts of P. goodeyi when their mean root densities were statistically similar to banana. When mean P. goodeyi root densities were significantly lower than banana but higher than 1000 100 g⁻¹ FRW, crops were classified as intermediate hosts. Crops with a mean P. goodeyi root density significantly lower than banana and lower than 1000 nematodes 100 g⁻¹ FRW were classified either as poor hosts (>20 P. goodeyi 100 g⁻¹ FRW) or very poor hosts (≤20 P. goodeyi 100 g⁻¹ FRW). Beans and maize (cv. CMS 8704) were good hosts of P. goodeyi; watermelon and onion were intermediate hosts; maize (cv. Kasaï), taro, okra, Irish potato and sweet potato were poor hosts, while cocoyam and tomato were very poor hosts.

Keywords:

• alternative hosts
• banana lesion nematode
• crop rotation
• host range
• tropical agriculture

Acknowledgements

The authors thank the ‘Vlaamse Vereniging voor Ontwikkelingshulp en Technische Bijstand' (VVOB) for supporting K. Jacobsen’s position at Bioversity/CARBAP, M. Marais, A. Swart and E. van den Berg (ARC-Plant Protection Research Institute) for species identification, and N. Buckley (ARC-Plant Protection Research Institute) for technical assistance. The Flemish Interuniversity Council (VLIR) supported L. Maes' position at CARBAP. The authors are also grateful for the support of R. Fogain during the set up of the field experiment.