Efficacy of granular insecticides against stem fly and nematode infestations in soybean with Rhizobium inoculant.
The effect of some granular insecticides on Melanagromyza sojae and 7 species of plant parasitic nematodes (Tylenchorhynchus vulgaris, Helicotylenchus indicus, Pratylenchus penetrans, Rotylenchulus reniformis, Heterodera cajani, Meloidogyne incognita and Hoplolaimus indicus [Basirolaimus indicus]) was studied in soyabean fields in Delhi, India, during 1988. Seeds were treated with Rhizobium japonicum [Bradyrhizobium japonicum] before sowing and phorate, quinalphos, mephosfolan and carbofuran were drilled into the soil. Only phorate, quinalphos and mephosfolan significantly reduced infestation by M. sojae. R. japonicum significantly increased the number of nodules, both with and without insecticides. The populations of all nematodes were reduced in insecticide-treated plots. Increased yields were observed for plots treated with insecticides and R. japonicum.