The effect of foliar calcium application on key (post) harvest quality attributes in Rabbit-eye blueberry (Vaccinium ashei)
Fruit firmness is considered a key fruit quality trait in blueberries. A fresh berry with an adequate firmness is required for keeping the rise of blueberries consumption worldwide. The amount of calcium associated to the cell-wall could positively affect the physical characteristics of the berry. Previously reported results associating foliar calcium treatment to blueberry firmness are not conclusive. Most studies on blueberry fruit do not account for the interaction between soil applied calcium, foliar applied calcium and harvest time. The aim of this study is to determine the interaction between calcium soil nutrition and pre-harvest foliar CaCl2 treatments on key (post) harvest quality attributes of Rahi blueberries harvested at different times. Five year old Rahi blueberries (Vaccinium ashei) were transplanted at bloom stage, and treated with two nutritional programs (low and high calcium). During the season, the plants were kept under glass-house conditions and foliar CaCl2 (16.9% Ca, Stopit, YaraVita, Norway) adjusted to pH 5.5 was applied at six times at Ca amount of 0 (control) and 250 mg plant‑1. Five harvest times were evaluated during the season. Low or null effect of calcium on key (post) harvest quality attributes were obtained. No interactions (p>0.05) between the nutritional program and foliar CaCl2 treatments were observed on TSS/TA ratio, weight loss and fruit texture parameters. However harvest time influenced fruit quality more than calcium treatments in this study. Further investigation of water relation variables such as water vapor permeance and cell turgor pressure evolution during storage, and/or anatomical and morphological attributes, could help to elucidate the effect of harvest time on postharvest fruit quality parameters such as weight loss and texture.
Rivera, S.A., Sofkova-Bobcheva, S., East, A., Hutchins, D. and Kerckhoffs, H. (2019). The effect of foliar calcium application on key (post) harvest quality attributes in Rabbit-eye blueberry (Vaccinium ashei). Acta Hortic. 1265, 135-144
berry fruit, calcium nutritional program, foliar CaCl2, texture profile analysis (TPA), harvest time