Journal of Crop Production and Processing

The effects of four levels of SO₂ (0.0%, 0.06%, 0.125% and 0.25%) on the qualitative and quantitative characteristics of two Persian grape cultivars “Keshmeshi seedless” and “Shahroudy” were evaluated during the cold storage in 1995-1997. This research was carried out in a factorial experiment in a completely randomized design in cold storage at the laboratory of Horticultural Department, College of Agriculture, Tehran University.

The results showed that the effect of SO₂ on decay was significant at 1%, and maximum control was obtained at 0.25%. No significant difference was observed when treated with 0.125% SO₂ However, increasing SO₂ concentration resulted in increased quantity and intensity of bleaching on the berries. At these increased concentrations, a linear relation was observed between bleaching on the berries and SO₂ concentration so that the highest bleaching occurred at a concentration of 0.25%. Increased storage periods also increased bleaching. The effect of SO₂ on weight loss, shattering, and rachis colour was also significant, decreasing rachis colour and shattering of berries.