Impact of mycorrhizal colonisation on grapevine establishment in Cylindrocarpon infested soil

Abstract

The effects of arbuscular mycorrhizae (AM), Glomus mosseae and Acaulospora laevis, on growth of six grape rootstock varieties and their infection by Cylindrocarpon species were investigated in a greenhouse experiment that challenged the mycorrhizal plants with a mixed inoculum of Cylindrocarpon spp. Both species of AM had beneficial effects (P<0.05) on rootstock growth but this effect was specific for particular rootstock and AM combinations. Generally, G. mosseae had a more consistent positive effect and A. laevis was the only species to decrease plant growth in some rootstock varieties. Subsequently, two field trials conducted in Auckland and Blenheim used a mixture of the two AM species and two rootstock varieties. After 9 months, compared to control plants mycorrhizal plants had similar incidence of Cylindrocarpon infection at both sites (P>0.05), but greater root dry weights in Auckland (214%; P<0.05) and Blenheim (only 22%; P>0.05). G. mosseae clearly has potential for improving health and growth of young grapevine plants.