Interaction of root-knot nematode, VAM fungus and neem cake in amended soils on gladiolus

Abstract

Interaction of neem cake, VAM fungus, Glomus fasciculatuln, and the root-knot nematode, Meloidogyne incognita, on floral growth characters, mycorrhizal root colonization and the development of root-knot disease in gladiolus was studied under green-house conditions. Both the neem cake and the VAM fungus increased the spike length, number of florets/spike and the floret diameter whereas the root-knot nematode reduced these floral growth characters. The neem cake at higher doses of 1 and 2% and the V AM fungus significantly increased the floral growth characters and suppressed root galls. These effects were significantly greater in the presence of neem cakelV AM fungus around nematode infected plants. Sporulation and mycorrhizal root colonization was suppressed at higher doses of the cake. Nematode multiplication was suppressed at all cake doses but was greatest at higher doses. Spore viability was lowest and nematode mortality was highest at higher doses of the cake after six weeks of exposure in amended soil. Lower doses of cake in combination with G. fasciculatum is suggested as a means to protect gladiolus from root-knot damage.