%0 Journal Article %A W. E. Wildman %A R. A. Neja %A A. N. Kasimatis %T Improving Grape Yield and Quality with Depth-Controlled Irrigation %D 1976 %R 10.5344/ajev.1976.27.4.168 %J American Journal of Enology and Viticulture %P 168-175 %V 27 %N 4 %X To define water management in relation to soil depth variations, an experiment was initiated in a typical vineyard in climatic region II in the Salinas Valley, California. Two irrigation treatments (HI = heavy-infrequent, based on a calendar schedule; LF = light-frequent, based on soil moisture readings by tensiometers) were replicated three times on soils of four depth groups (36-43, 46-61, 76-122, and 152-213 cm) within one block of Chardonnay grapes. Data collected in 1972-75 gave the following significant yield results. LF vines averaged 8.8 kg grapes per vine, while HI vines averaged 7.4 kg; vines on soils of shallow and intermediate depths outyielded those on the deepest soils (36-43 cm, 7.4 kg; 46-61 cm, 8.4 kg; 76-122 cm, 9.9 kg; 152-213 cm, 6.8 kg). Yield of fruit sugars per vine closely paralleled yield of grapes. Total soluble solids were significantly higher for LF than for HI vines (22.7 vs 22.3°B) but not significantly different among soil depths. Total acidity was significantly and excessively higher in the HI than the LF vines (1.14 vs 1.04%), particularly at greater soil depths, an indication of immature grapes produced on the deeper, more moist soils. pH of grapes was not significantly different between irrigation treatments but was significantly lower in the deepest soils (36-43 cm, 3.27; 46-61 cm, 3.28; 76-122 cm, 3.26; 152-213 cm, 3.18). %U https://www.ajevonline.org/content/ajev/27/4/168.full.pdf