Field Inoculation with VA Mycorrhizal Fungi

One of the greatest impediments to vesicular-arbuscular mycorrhizal (VAM) fungi inoculation of field crops is the bulk and weight of inoculum required. The Glomus spp. inoculum was then shown to be the best inoculant with pukekohe long keeper onions in a field trial on the Patumahoe soil, amply vindicating the effort of prior fungal selection. Pure cultured inoculum of VAM fungi is not yet available, thus, in many field trials, plants have been inoculated by placing pads of mycorrhiza-infested soil below each seed. Pelleting is a successful inoculum formulation when the seedling radicle passing down through the inoculum becomes primarily infected with the fungi in the pellet before it comes into contact with the indigenous mycorrhizal fungi in the field soil. Inoculum placement is not crucial, as the nursery potting mix can be thoroughly infested with VAM inoculum, and there are no indigenous mycorrhizal fungi to compete with the inoculant fungi for root space.