Response of bambara groundnut (Vigna subterranea l. Verde.) cultivars to root–knot nematode (Meloidogyne javanica)
A screen house experiment was conducted at the Federal University of Technology, Yola (Latitude 90 30’N and Longitude 120 11’E at an altitude of 185.9 m above sea level) to study the response of eight cultivars of Bambara groundnut (Vigna subterranea L. Verde) to root-knot nematode (Meloidogyne javanica). The cultivars were Fara sola, Sola I, Sola II, Warki, Kiya, Gujiyan kurege, Roko and Bayan jiki. These were sown in 4 litre plastic pods each filled with 2.5 kg of sterilized soil mixed with cowdung at a ratio of 3:1. Tomato roots infected with root-knot nematode were obtained from a farmer’s field. Meloidogyne females and their egg masses were removed using forceps and needles. Perennial pattern of each of these were prepared and observed under the microscope and M. javanica and its eggs were identified. The egg masses were cultured in plastic pods containing tomato seedlings. Eight weeks later, the tomato plants were uprooted and the egg masses of M. javanica isolated. Five egg masses were then inoculated into each of the Bambara groundnut cultivar one week after emergence. The experiment was arranged in a completely randomized design replicated three times. The plants were allowed to grow until harvest. At harvest, data were collected on plant height, root length, root gall index, number of M. javanica egg masses, juveniles in soil and yield weight per plant. Data obtained were subjected to analysis of variance. Results showed that all the eight cultivars studied were susceptible to root–knot nematode at varying degree with some signs of resistivity in some cultivars which enabled them performed better than others even with the infection. Sola II displayed the ability of resisting attack and recorded the tallest plant (17.19 cm) and highest seed yield (4.67 g plant-1) compared with the others. It is therefore recommended that farmers should adopt Sola II in order to boost Bambara groundnut production in Adamawa State, Nigeria, where the soil is infested with M. javanica.