| Autor: |
W. A. M. Daundasekera, G. L. S. G. Liyanage, R. Y. Wijerathne, R. Pieris |
| Rok vydání: |
2015 |
| Předmět: |
|
| Zdroj: |
Ceylon Journal of Science (Biological Sciences). 44:55-60 |
| ISSN: |
0069-2379 |
| DOI: |
10.4038/cjsbs.v44i1.7341 |
| Popis: |
Developing fruits of local tomato cultivar ‘Rajitha’ were subjected to different preharvest calcium treatments in order to determine an effective means of extending the keeping quality of the commodity. Treatments were conducted with two calcium concentrations (3% and 5% w/v). There were two spraying protocols; single-application on fruit at 7 days after full bloom (DAFB) and multiple- application viz. weekly spraying starting from 7 DAFB until harvesting. Fruits were harvested at turning stage of colour development and allowed to reach red ripe stage under ambient conditions. Observations were made on the shelf life, titratable acidity (TA), total soluble solids (TSS) content, total calcium content in the outer pericarp and % weight loss during storage. Effect of calcium chloride treatment on susceptibility to fungal diseases was tested on fruits harvested at the ‘turning stage’ on wounded and non-wounded tissues. Rot development with respect to time was tested for both natural disease development and under artificial inoculation with fungal species isolated from tomato fruits. Calcium chloride treatment resulted in a 2.3 to 3.8-fold extension of shelf life of fruits compared to non-treated ones. Calcium treated fruits also exhibited a significantly higher firmness, total calcium content in the outer pericarp and TSS content but significantly lower fresh weight at harvest and a greater weight loss during storage under ambient temperature (27 ±2 0C). Calcium treatment has no consistent relationship with the % TA of fruit. Aspergillus niger and Rhizopus stolonifer were identified as the main postharvest fungal pathogens in tomato. Disease severity was less in Ca2+ treated fruits and the significance of this effect varied between pathogenic fungal species. Irrespective of the Ca2+ treatment, wounded fruits exhibited higher disease severity under natural conditions and also upon artificial inoculation. The extended shelf life in calcium-treated tomato appears to be through higher retention of firmness and retardation of skin colour development. Ceylon Journal of Science (Bio. Sci.) 44 (1) : 55-60, 2015 |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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