Calcium applications under sub-optimal and optimal substrate calcium conditions for rabbit eye blueberry

Hard berry texture is currently one of the most important quality attributes to assure fruit acceptability by consumers. The amount of calcium associated with the cell wall may affect fruit texture. Therefore foliar calcium applications are considered as a management practice among blueberry growers. However, the reported results associated with the effect of foliar calcium treatments on blueberry hardness are not completely conclusive. Most of the studies on blueberry fruits do not explore the interaction effect between the soil available calcium and the foliar calcium application. The aim of this study is to determine the effect of foliar calcium application on the fruit texture and fruit calcium concentration. Five-year-old ?Rahi? blueberries (Vaccinium ashei) were transplanted at bloom stage into 45 L pots with two different calcium amounts (5 g and 0.5 g Ca per pot). After transplanting, the plants were kept under glasshouse conditions. Foliar calcium chloride (16.9% Ca; Stopit, YaraVita, Norway) adjusted to pH 5.5 was applied at a rate of 250 mg/plant at eight developmental stages from fruit-set until mature-blue fruit. Plants treated with buffer only (pH 5.5) at the same eight stages were considered as a control. During the plant growing period the physiological parameters of photosynthesis and stomatal conductance were assessed. At harvest and during postharvest storage the fruit hardness (texture analysis) and the calcium concentration were determined. This paper will discuss the relevance of foliar calcium applications under sub-optimal and optimal substrate calcium conditions. ? SourcesTHE EFFECT OF FOLIAR CALCIUM APPLICATIONS ON KEY (POST) HARVEST FRUIT QUALITY ATTRIBUTES IN RABBIT-EYE BLUEBERRY (Vaccinium ashei)Sebasti?n Rivera*, Svetla Sofkova-Bobcheva, Andrew East, Daniel Hutchins, Lhj KerckhoffsInstitute of Agriculture and Environment, Massey University, Tennent Drive., Palmerston North, New Zealand*sebastian.rivera@inia.clICH2018 Istanbul, 30th International Horticultural Congress, 12-16 August 2018, Turkey Picture by?Gardens Oy Vey?