- Joanie Kift
- Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200
- 2000
Calcium (Ca) spray applications during the fruit development stages have improved fruit quality in many crops. During this study seven different commercial Ca products were tested to investigate the effect they have on litchi fruit size and fruit quality. The best results were obtained in McLean’s Red. Ca treatments improved the taste and firmness with McLean’s Red and in some treatments reduced the fruit weight loss during the cold storage period of 25 days. Fruit size was not adversely affected by calcimax, but all the other treatments slightly reduced the fruit size of McLean’s Red. Results for HLH Mauritius were more variable, but fruit firmness was improved and weight loss reduced by some treatments.
Summary:
Calcium (Ca) sprays during fruit development stages have shown to improve fruit quality in many crops, but limited prior research existed on litchis.
Ca plays a crucial role in cell membrane structure, delaying senescence, reducing membrane leakage, and is important for pollen germination and fruit retention.
Seven different commercial calcium products were tested on HLH Mauritius and McLean’s Red litchi cultivars for effects on fruit size, firmness, weight loss, and yield.
For HLH Mauritius, calcium treatments did not significantly affect yield, fruit set, or average fruit size; however, Symspray (containing cytokinins) improved fruit set and yield.
Calcimax treatment resulted in the largest average fruit size in HLH Mauritius.
For McLean’s Red, calcium treatments generally slightly reduced fruit size except for Calcimax, which increased larger fruit size categories.
All calcium treatments except Calcium Dextrolac improved fruit firmness in McLean’s Red after 25 days cold storage; Basfoliar calcium and Caltrac treatments showed the greatest firmness improvement.
Basfoliar calcium treatment also minimized fruit weight loss during and after cold storage, helping maintain fruit quality.
Some incidences of fruit browning were observed with Basfoliar calcium, possibly linked to timing of sprays relative to flowering.
Calcium sprays offer potential benefits in improving firmness, reducing weight loss, and enhancing fruit quality particularly in McLean’s Red litchis.
More research is needed before definitive recommendations can be made on calcium spray use and selection of products due to variability in results.