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Foliar calcium (Ca) products are applied by many berry growers to enhance fruit quality and shelf life without evidence that these applications increase fruit Ca or impact fruit characteristics when applied at rates recommended on the product label. The objectives of this study were to determine if fruit or leaf Ca increases when several formulations of liquid Ca products are applied to developing fruit, and to assess any resulting changes in freshmarket quality of berries. Products were applied in strawberry (Fragaria 3ananassa L., ‘Hood’ and ‘Albion’), raspberry (Rubus idaeus L., ‘Tulameen’ and ‘Vintage’), blackberry (Rubus L. subgenus Rubus, Watson, ‘Obsidian’ and ‘Triple Crown’), and blueberry (Vaccinium corymbosum L., ‘Spartan’, ‘Liberty’, ‘Draper’, and ‘Legacy’). Calcium formulations tested were Ca chloride (CaCl2), CaCl2 + boron, Ca silicate, Ca chelate, and Ca acetate, which were compared with a water-only control. The rates used for each product were within ranges specified on the label and supplied equal amounts of Ca per ha for each treatment; the Ca concentration varied from 0.05% to 0.3% depending on the cultivar and the volume of water required for good coverage. All products were applied with a backpack sprayer, except in a separate trial where a backpack and electrostatic sprayer were compared in ‘Draper’ and ‘Legacy’. Treatment applications were started at the early green fruit stage and were repeated three or four times, depending on duration of berry development and cultivar. Fruit were harvested into commercial clamshells 4 days to’4 weeks after the final application of Ca from an early harvest at commercial ripeness. Data collected included berry weight, rating of fruit appearance and flavor, firmness, skin toughness, total soluble solids (TSS), and weight loss and nesting (collapse of fruit) during storage (evaluated at ’5-, 10-, 15-, and 20-days postharvest). Fruit and leaves were sampled at harvest to determine Ca concentration. There was no evidence of spotting or off-flavors due to Ca applications. Compared with the control, none of the Ca treatments or method of application changed leaf or fruit Ca concentration, fruit quality, firmness, or shelf life in any crop or cultivar tested. The Pacific Northwest region of the United States is an important growing region for the production of blueberry (V. corymbosum L.), blackberry (Rubus L. subgenus Rubus, Watson), raspberry (R. idaeus L.), and strawberry (Fragaria ·ananassa L.) (USDA National Agricultural Statistics Service, 2015). Production of high-value fruit for the fresh market is increasing in many of these crops. Growers need to produce high-quality fruit that has the maximum possible storage or shelf life to be competitive in the market place. Calcium is often applied to fruit crops before harvest at the recommendation of some crop consultants in an effort to increase postharvest fruit quality. Fruit Ca has been found to be related to fruit firmness by strengthening the cell wall, which, in turn, improves shelf life (Van-Buren, 1979). Blueberry (Strik and Vance, 2015) and blackberry (Harkins et al., 2014) cultivars have been found to differ in fruit Ca concentration. When soil Ca levels are sufficient, localized Ca deficiency such as in leaves or fruit may still become a problem in fruit crops. Calcium-related disorders include bitter pit in apple fruit (Malus domestica, Borkh.), blossom-end rot in tomato (Solanum lycopersicum L.) fruit, and tipburn in leaves of vegetables (Saure, 2005). These deficiencies in Ca may occur as a result of competition between vigorously growing shoots and fruit. Strik and Vance (2015) speculated that ‘Draper’ blueberry may have particularly low fruit Ca concentration due to the presence of many competing shoot tips during the fruit development period. Since Ca is translocated in the xylem and not the phloem, Ca is relatively immobile in the plant and tends to move predominantly to leaves, which have a high transpiration rate. Penetration of Ca into fruit likely occurs through the stomata on the fruit surface. Penetration rates, however, have been shown to vary with cultivar, application method, and formulation of Ca used (Saure, 2005). The number of possible interactions that can affect Ca uptake and distribution in the plant is so complex that cultural management practices are not likely to increase fruit Ca, without a direct application of Ca to the developing (Bangerth, 1979) or harvested (Hanson et al., 1993) fruit. Postharvest dips with CaCl2 increased firmness and shelf life of raspberries and blueberries, but resulted in an unacceptable salty taste (Hanson et al., 1993; Montealegre and Valdes, 1993); washing or dipping fruit also removes the desirable, waxy bloom coating on blueberry fruit and decreases shelf life in blackberry, raspberry, and strawberry. Foliar Ca applied to strawberries has been shown to delay fruit harvest, reduce incidence of fruit rot and improve fruit firmness (Cheour et al., 1990; Singh et al., 2007; W ojcik and Lewandowski, 2003). In blackberries, preharvest Ca applications did not impact initial fruit firmness following machine harvest, but had a positive effect during storage (Morris et al., 1980). Hanson (1995) applied CaCl2 to blueberry plants with minimal impact on fruit quality. The objectives of this study were to test several Ca formulations with direct sprays of liquid products applied to developing fruit of strawberry, raspberry, blackberry, and blueberry cultivars and determine the impact on Ca concentrations of fruit and leaves, and fruit quality at harvest and during storage. Two methods of application were compared to assess the impact of spray coverage on

Foliar Calcium Applications Do Not Improve Quality or Shelf Life of Strawberry, Raspberry, Blackberry, or Blueberry Fruit