Effects of Calcium-Containing Foliar Sprays Combined with Titanium and Algae Extract on Plum Fruit Quality

Abstract

An experiment was performed in which soluble calcium (Ca) was sprayed on plum trees in combinations with two bioactivators containing (Ti⁺⁴)-ascorbate and/or marine algae extract to study the effects on the commercial quality of fruits, with special attention paid to any increase in their resistance to postharvest handling damage. All the treatments containing titanium (Ti) increased tree development and fruit size. At harvest, fruits from the Ti-treated trees increased resistance to compression and penetration, but decreased weight-loss during postharvest storage. External red color was also improved and the color parameters remained more stable during storage as compared to the control fruits. Titanium application led to significant increases in the Ca, iron (Fe), copper (Cu), and zinc (Zn) concentrations in both peel and flesh. The improvement in Ca assimilation can be explained by the beneficial effect of Ti on absorption, translocation and assimilation processes.

Keywords:

• Algae extract
• Calcium
• Color
• Firmness
• Fruit quality
• Mineral composition
• Plum
• Prunus salicina
• Size
• Titanium

Acknowledgments

The authors gratefully acknowledge financial support provided by CICYT (Spain) project ALI99-1058-C02-01, and wish to thank MOLINENSE PRODUCTOS NATURALES, S.L., for its assistance in the experimental work, and PRODUCTOS LIFE, S.L. for providing the LIFE-CALCIO® and LIFE-MAR® used in the experiments.