Growth-Yield Relationship of Grapevine Cultivars on Soils with Hardened Layers, Alto Valle of the Rio Negro, Southern Wine-Growing Region of Argentina

the aim of this work was to evaluate the vegetative-productive balance of vitis vinifera l., cvs. merlot, malbec and cabernet sauvignon on aridisols with hardened layers in the alto valle of rio negro, argentina. the study was carried out in 15.5 ha of vineyards during 2002-2003 on five soil groups characterized by: type, thickness and depth of the horizons, texture and resistance to penetration. in each sampling site three plants were evaluated. production, leaf area, pruning material, trunk diameter, the ravaz index, the leaf area/yield ratio and the leaf area index were determined. a variance analysis and means comparison were made. the production level, the leaf area and the pruning material of the three cultivars were reduced (p < 0.05) when the soils presented extremely hard horizons (resistance to penetration greater than 3 mpa) at a depth of 35 cm or less and with 30 cm or more of thickness, indicating a low site potential. the ravaz index and the leaf area/yield ratio didn't show differences (p < 0.05) among soil groups in any cultivar. in soils with restricted properties, but with an adequate growth-yield balance, smaller vine spacing and avoiding gaps between vines can be used to increase production.