Managing Arbuscular Mycorrhizal Fungi in Arid Columbia Basin Vineyards of the Pacific Northwest United States

Abstract Background and goals Arbuscular mycorrhizal fungi (AMF) are root symbionts that help grapevines acquire nutrients from soil. Growers in many regions, including the Columbia River basin of Oregon Washington, lack information needed to best manage AMF. Such lacking includes understanding whether natural AMF populations sufficient ensure healthy colonization new plantings, what factors influence established plantings. Methods key findings grapevine fine roots was determined 32 commercial vineyards a vineyard heavily infested by northern root-knot nematode (NRKN, Meloidogyne hapla). Root as extensive young vines (one- two-years-old) older (>15-years-old) examined survey, high throughout season single trial. greater overall red wine grape cultivars than white cultivars. correlated negatively with soil nitrate leaf nitrogen (N) concentrations across vineyards, while arbuscules NRKN Both per unit length at beginning end growing vineyard. Conclusions significance Results suggest soils ample levels colonization, so inoculation is likely not when planting or replanting region. reduced N