How does crop load influence fruit quality and subsequent vine growth?
Growers have reported that Redglobe vines which carry a large crop in one season often exhibit delayed budbread and reduced fruitfulness the following spring. In extreme cases, if crop load is not properly managed, the vines may enter into a pattern of alternate bearing in which fruit yields vary significantly between seasons. After observing these symptoms in 1990 and 1991, we decided to test the hypothesis that delayed growth and reduced vine fruitfulness were related to crop load in the previous season. An experiment was initiated in 1992 in a mature Redglobe vineyard located near Delano, CA. Vines were selected on the basis of uniform vigor and fruit development. Crop load was adjusted to either 10, 20, 30 or 40 clusters per vine immediately after fruit set. Care was taken to assure uniform crop distribution (i.e. cluster number per cordon was equal), and each treatment was replicated 8 times using single vine plots in a randomized complete block design. Cultural operations were pe
