Root-Knot Nematodes (Meloidogyne spp.) Infestation and Reproduction on Soybean (Glycine max L. Merrill) Treated with Varying Doses of Gamma Rays

Abstract

A study was carried out on a root-knot nematode (RKN), naturally infested field at the Department of Agronomy, University for Development Studies, Nyankpala campus during the 2017 major cropping season. The objective was to evaluate the potential of root-knot nematodes to infest and reproduce in soybean cultivar 'Jenguma' treated with different doses of gamma rays. The experiment consisted of 5 treatments viz- soybean seeds irradiated with 150 Gy, 200 Gy, 250 Gy, 300 Gy and 0 Gy doses of gamma rays. The treatments were replicated three times in a randomized complete block design. Yield of soybean and reproduction index of RKN were determined at 10 WAP. Results of the study showed that soybean seeds irradiated with 150 Gy recorded maximum fresh and dry root weights of 24.32 g and 0.90 g respectively whilst treatment 300 Gy recorded the lowest mean fresh and dry root weights of 15.00 g and 0.80 g respectively. Plants treated with 150 Gy produced crops with heavier grains of 4.65 t/ha compared to 1.37 t/ha produced by unirradiated seeds. Seeds treated with 150 Gy had the least root galls, fewer number of second stage juveniles of root-knot nematodes and lowest reproduction index of 0.47, 44 and 8.46, respectively, compared to other treatments. The study therefore concluded that treating soybean var 'Jenjuma' with a dose of 150 Gy increased its resistance to RKN infestation and hence suggested for use in the management of root-knot nematodes in soybean production.

Key words: Gamma irradiation, root-knot nematodes, reproductive index, resistance, soybean