Vineyard floor management improves wine quality in highly vigorous <i>Vitis vinifera</i> ’Cabernet Sauvignon’ in New Zealand

Abstract

Abstract Five inter‐row soil management techniques were applied to a vigorous Vitis vinifera ’Cabernet Sauvignon’ vineyard in Hawke's Bay, New Zealand—a permanent chicory ( Chicorium intybus var. sativum ’Puna') cover crop; chicory sprayed with herbicide before veraison; incorporated pine ( Pinus radiata ) sawdust and bare soil maintained using cultivation or non‐selective herbicide. Both chicory treatments significantly reduced the soil water content and shoot growth late in the season compared to the other treatments. Petiole nitrate concentration and leaf size were lowest in the sawdust and both chicory treatments. The pruning weights in the two chicory treatments were reduced to about half those found in the other treatments. No significant differences among treatments were found in yield or other viticultural characteristics examined. Both chicory treatments resulted in advanced ripening (increased soluble solids and decreased titratable acids), increased anthocyanins, and reduced ammonia content of berries compared to other treatments. Sensory evaluation of wines produced from the cultivation (bare soil) and the permanent chicory cover crop treatment were conducted after 4 years of bottle age, and showed riper fruit aroma and flavour and a higher overall quality score in the chicory treatment. Competition imposed for two seasons using a permanent chicory cover crop has resulted in improved viticultural and oenological characteristics of a highly vigorous ‘Cabernet Sauvignon’ vineyard in a marginal site in New Zealand.