California Agriculture

Table grapes commonly suffer from tissue browning during harvest, packing, storage and shelf life, resulting in lower prices and reduced access to markets. We evaluated the development of browning symptoms in ‘Princess’ table grapes. The berries had high skin browning but very low flesh browning incidences. The most skin browning was found in highly mature grapes and appeared after 3 weeks of cold storage. Skin browning was directly related to fruit maturity, but vineyard location had a greater impact on the incidence of skin browning than maturity. In all locations, the skin browning susceptibility of ‘Princess’ table grapes rapidly increased when the berries reached a titratable acidity of less than or equal to 0.60% and/or a soluble solids concentration greater than or equal to 18.0%. Based on this work, we recommend harvesting ‘Princess’ at a soluble solids concentration between 16.0% and 18.0%.