Differential Growth of Mycorrhizal Field-Inoculated Grapevine Rootstocks in Two Replant Soils

Abstract

The mycorrhizal field inoculation of 161-49 Couderc (<i>Vitis riparia</i> Michx. x <i>Vitis berlandieri</i> Planch.) and 140 Ruggeri (<i>Vitis rupestris</i> L. x <i>V. berlandieri</i>) grapevine rootstock plants grafted with Cabernet Sauvignon was evaluated in two replant soils of a Mediterranean production area in northeastern Spain. The first soil (vineyard 1) had been under tillage for 10 years. The second soil (vineyard 2) had been cultivated for one year before setting up the new plantation and was infested by the white root rot fungus <i>Armillaria mellea</i> (Vahl:Fr.) P. Kumm. The number of infective mycorrhizal propagules estimated in the soil before planting was 1 per 100 mL soil in vineyard 1 and none in vineyard 2. Half of the vines for each rootstock were inoculated with the arbuscular mycorrhizal fungus (AMF) <i>Glomus intraradices</i> Schenck and Smith (BEG 72). In vineyard 2, lacking mycorrhizal propagules and infested with <i>A. mellea</i>, soil was also inoculated before planting with <i>Thymus vulgaris</i> L. and <i>Lavandula officinalis</i> Mill. plants colonized by <i>G. intraradices</i> in two rows. At the end of the second growing season, 19 months after planting, the direct field inoculation showed a beneficial effect on the growth of 140 Ruggeri vines in vineyard 1. The total biomass of inoculated 161-49 Couderc vines increased in vineyard 2 but not in vineyard 1. Precropping with mycorrhizal carrier plants increased the mycorrhizal potential of the replant soil. Grapevine response to AMF inoculation was influenced by the intrinsic characteristics of the vineyard soil and by the rootstock used and the time after planting.