Efficiency of some salts on the incidence of grape bunch rot caused by Botrytis cinerea in the field and during storage and fruit characteristics of Flame seedless grapevines [electronic resource].

Includes references.

The efficiency of calcium chloride, calcium nitrate, potassium metabisulfite. calcium carbonate and sodium bicarbonate was assessed by in vivo and in vitro tests against grape bunch rot in field and storage conditions by spraying salts three times. the first at bloom stage. the second after two weeks from the first spray and third after two weeks from the second spray. The investigation was carried out in a private Vineyard EI-Khatatba region. Cairo -Alexandria desert road during two growing season, 2006/2007 on Flame seedless grapevines. All tested salts were found to reduce the growth of Botrytis cinerea Pers. through the use of three concentrations 0.05%, 0.1% and 0.2% a complete inhibition was achieved by Potassium metabisulfite at the rate of 0.2% and by Sodium bicarbonate at the rate of 0.2%. All tested salts significantly reduced disease severity of bunch rot in field conditions, the highest percentage of reductions was shown when vines were treated by Potassium metabisulfite during seasons 2006 at the rate of 2g/L. Field applications of salts resulted in a significant reduction of botrytis storage rots. Potassium metabisulfite was the most effective treatment to control rots on naturally and artificially infected at the rate of 2g/L. in both seasons during storage at 0°C under 90-95% R.H. for 50 days. Fruit physical and chemical were positively affected by different treatment. All applied salts increased cluster weight and yield I vine except sodium bicarbonate and calcium chloride were a decrease in these parameters. Weight and berry diameters were positively affected by all applied salts except sodium bicarbonate. A similar positive effect was also observed concerning TSS, total acidity and TSS/TA ratio for grapes stored for 50 days at 0°C and 90-95% R.H. with the exception of sodium bicarbonate which reduced juice acidity and TSS /TA ratio. Loss of weight after cold storage of grapes was substantially decreased in all salts treatments. Form the economic point of view, the cost of using salts is very cheap compared to use classic fungicide and also increased yield to 1404.8 and 2205.6 kg/ fed in season 2006 and 2007 respectively; in addition the fruit quality was improved.

Summary in Arabic.

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