Response of Five Cowpea Varieties to Some Phytonematodes under Field Conditions

Abstract

Five cowpea varieties viz Asomdwe, Asetenapa, Hewale, Nhyira and Videza, were evaluated for their reaction to plant parasitic nematodes under natural infestation. Meloidogyne incognita, Pratylenchus brachyurus, and Rotylenchulus reniformis were isolated from the rhizosphere of the cowpea varieties although each of the varieties reacted differently to these nematode species. The highest number of M. incognita was recovered from the rhizosphere of Asomdwe which was 83% higher than Asetenapa which recorded the least number of M. incognita. Similarly, there was a significant difference (P<0.05) between R. reniformis juveniles recovered from the rhizosphere of Hewale and all the other varieties. There was however no significant differences in the number of P. brachyurus recovered although Nhyira recorded the highest. Two of the nematode genera- Meloidogyne incognita and Pratylenchus brachyurus were extracted from the roots of the various varieties with varied population densities. The highest grain yield was recorded in Hewale. It out yielded Nhyira, Videza, Asomdwe and Asetenapa by (58, 49.8, 41.5 and 11.9)% respectively.