Prevalence and farmers' perceptions of parasitic nematodes in yam rhizosphere soils from some yam producing areas of Ghana

Abstract

Rhizosphere soil samples of yam from Adidwan, Ejura, Kintampo, Mampong, Nkoranza and Techiman, in the transitional agro-ecological zone of Ghana, and yam tubers from Techiman market were analysed for the presence of plant parasitic nematodes in August and September, 2002. Yam farmers from the areas were also surveyed using questionnaire to determine their perceptions of nematodes. Thirteen genera of nematodes were identified in the yam rhizosphere soil samples. These were Aphelenchoides, Criconemella, Helicotylenchus, Hoplolaimus, Longidorus, Meloidogyne, Paratylenchus, Pratylenchus, Rotylenchulus, Scutellonema, Trichodorus, Tylenchus and Xiphinema. Of these, Aphelenchoides, Meloidogyne, Paratylenchus, Pratylenchus and Rotylenchulus were found in all the six yam- growing areas. The most frequently detected genus was Pratylenchus (21.8% relative abundance) and the least was Longidorus (0.4%). All yam tubers purchased from the market were infected by parasitic nematodes such as Meloidogyne, Pratylenchus and Scutellonema with Pratylenchus being the most frequently recovered. Farmers had poor perceptions of yam nematodes. Apart from Techiman and Ejura where 40 and 10%, respectively, of yam farmers knew about nematodes, farmers from the remaining areas did not know about the pest. Planting materials were not treated for control of nematodes.

Keywords: yam, dioscorea, plant parasitic nematodes, rhizosphere soil, transitional agro- ecological zone

Agricultural and Food Science Journal of Ghana Vol. 3 2004: 217-226