1985 Volume 53 Issue 4 Pages 396-404
Several viticultural characteristics of the 3 wine-grape cultivars, changes in chemical composition of the berries during ripening, and quality of the wines from the grapes were investigated over 3 years from 1980 to 1982. The cultivars tested were ‘Seibel 9110’, ‘Seibel 13053’ and ‘Seibel 8745’ belonging to french hybrid, cultivated on the experimental vineyard of Yamanashi University.
The results are summarized as follows:
1. The mean weight and diameter of berries, and the mean weight of clusters reached the following maxima, 2.8g, 16.0mm and 480g in early September for ‘S. 9110’, 2.0g, 15.0mm and 230g in late August for ‘S.13053’, and 2.8g, 16.0mm and 250g in early September for ‘S.8745’. These cultivars were small berry types (i.e. a berry weight below 3.0g).
2. At full maturity, the pH values of all the musts from the cultivars tested were 3.4.
3. It was known that the two cultivars ‘S.9110’ and ‘S.13053’ were low-acid types, and that their harvest times might be decided by acidity rather than °Brix. On the other hand, ‘S.8745’ was a medium-acid type and the acidity of the must was more than 0.8g/100ml at full maturity.
4. The maximum °Brix of ‘S.13053’ and ‘S.9110’ were 16.0%, in late August, and 17.0%, in mid-September, respectively. The °Brix of ‘S.8745’ reached 20.0% in late September in warmer years but in cooler years the °Brix was very low.
5. At full maturity, the glucose-fructose ratios and the tartaric-malic acid ratios of ‘S.9110’ and both ‘S.13053’ and ‘S.8745’ were 0.9 and 1.5, and 1.0 and 2.0, respectively. Cultivar ‘S.9110’ was a high-fructose type, while ‘S.13053’ and ‘S. 8745’ were high-tartaric acid types.
6. In both ‘S.9110’ and ‘S.13053’, the summation of temperature necessary for reaching full maturity was low, so these cultivars seemed to be adapted to cultivation in cool areas.
7. All the 3 cultivars tested were productive and easy to cultivate, so it was necessary to regulate the cropload.
8. The ‘S.9110’ wine had a fruity aroma, a slightly acid taste, and the color changed rapidly to brown. The ‘S.13053’ wine had a slightly noble aroma, but a flat or insipid taste due to low acids and tannins. The ‘S.8745’ wine had tart, astringent and tough tastes, but lacked a noble aroma.