Effect of Foliar Application of Calcium on the Quality of Blueberry Fruits

ABSTRACT

Effect of foliar application of calcium (0.78 g, 4.68 g, and 7.8 g Ca^{2 +}) in pre-harvest, at three different growing conditions (tunnel, mesh, and ambient), on texture and pectin in blueberries (Vaccinium corymbosum) was studied. Calcium contents in leaves as well in fruits were different (P ≤ 0.05), affected by growing conditions and time. Differences (P ≤ 0.05) in calcium content were found in tunnel cultivar fruit, during the period to cell expansion toward harvest, at calcium foliar level of 5 mL per L (7.8 g). Fruit texture was significantly higher at the beginning of the cell expansion period in the tunnel cultivar fruit, and a linear correlation between calcium concentration and texture was established. Increment in low methoxyl pectin (LMP) was influenced by growing conditions, and was different (P ≤ 0.05) for tunnel cultivar fruit. A good correlation between LMP and calcium content was obtained with the high dose of calcium (5 mL per L).

Keywords:

• Blueberries
• calcium
• low methoxyl pectin
• texture

ACKNOWLEDGMENTS

This study is part of Research Project 2002 in the Department of Research, Universidad de Los Lagos. We would like to express our gratitude to Mr. Julio Giddings and Mr. Roberto Giddings at Empresa Agrícola Giddings.

Notes

∗denotes a statistically significant difference.

∗ denotes a statistically significant difference.