Efficacy of Foliar Application of Calcium Products on Tomatoes as Defined by Penetration Depth of and Concentration within Fruit Tissues

Abstract

The efficacy of ion absorption through the cuticle of a leaf of fruit has been related the conditions whilst applying (i.e., environmental) and the receiving surface exposure (i.e., area covered, capacity of absorption). The influence of the product's physical chemical properties like point of deliquescence should be taken under consideration while quantifying penetration. The present study compares traditional and recent calcium formulations (total of 10) by evaluating calcium penetration and distribution on tomato fruits as well as comparing plant health and fruit quality. Elemental analysis through Wavelength Dispersive X-ray Spectrometer (WDS) analysis, using a Zeiss EVOR_MA15 SEM (Carl Zeiss Pty. Ltd., Cape Town, South Africa) and mineral analysis were used to quantify calcium content in the fruit. In addition, maturity index parameters were taken before and after storage (10 days at 15°C). Nitrogen, phosphorus, magnesium and calcium did not differ significantly after treatment according to elemental and mineral analysis. Calcium concentration in the fruit was successfully increased.

Keywords:

• foliar application
• scanning electron microscope
• commercial calcium products

ACKNOWLEDGMENTS

This project was carried out with assistance of the following co-workers: Hendri Botha from Terason/ Ag-Chem Africa and Werner van der Nest from Nexus/ Ag-Chem Africa. Dr Lynn Hoffmann contributed greatly towards the preparation of the manuscript.