VINEYARD IRRIGATION TRIALS

Grapes Have received less attention than of the rows, were untreated buTTer zones other California crops in irrigation re- Between plots. Thus, each plot consisted search. Studies by Hendrickson and Veih- of 20 vines in a single Basin, separated meyer (4)in various locations in California from the actiacenf plot by 24 feet of un-make up much of the research in this field, treated area. The experiment had 3 re-These workers corroborated their earlier plicafed irrigation treatments, randomly findings thafplanfgrowfh of orchard crops distributed. is relatively unaffected by soil moisture The soil was Yolo clay loam, a deep el-deficits as long as the permanent wilting luvial soil of fairly uniform texture and high percentage (PWP) has not been reached, fertility. Table I represents the ~4 and 15 Little information is avaiable, however, on atmosphere values (7) of this soil at various the physiological response of the grapevine depths for each of the treatment plots. fo soil moisture deffcifs. These data are approximate values of field This study evaluates the response of the capacity and PWP. grapevine fo wafer deficits and by incud- Soil moisture was measured by tub