Department of Plant Pathology, Regional Agricultural Research Station, Aacharya N. G. Ranga Agricultural University, Tirupati-517502, Andhra Pradesh, India.
Root nodulation, nodule dry weight and pod yield were significantly more in Rhizobium inoculated control than un-inoculated control in both pre-and post-inoculation chemical seed treatment experiments conducted in rice fallows. Thiram and mancozeb were proved to be non-toxic to Rhizobium in both pre-and post-inoculation seed treatments and gave more nodulation, dry weight of nodules per plant and pod yield over the controls. Post seed treatment with carbendazim, Benlate and carbofuran against Rhizobium inoculum was found to be beneficial and gave more nodulation, dry weight of nodules and pod yield. However, pre-seed treatment with the same chemicals failed to increase nodulation, dry weight of nodules and pod yield over inoculated control. Captan and carbosulfan were found to be toxic to Rhizobium and decreased nodulation and pod yield over the controls. Post-seed treatment with pesticides is preferable than pre-seed treatment against Rhizobium since it gave better nodulation and pod yield.
