Storage of inoculated and omethoate-treated medic seed reduces effectiveness of rhizobial inoculant

Abstract

The effectiveness of medic inoculation with Rhizobium meliloti was significantly reduced when inoculant was applied to seed pretreated with the organophosphorous insecticide omethoate and stored for 5 days until seeding. Average nodule number and shoot weight per plant were reduced to 6 and 22% of a nil omethoate treatment. When medic seed that was not stored before sowing was seeded into moist soil, its pretreatment with omethoate had no significant effect on nodulation and increased plant weights.