SEASONAL VARIATIONS VERSUS SOME QUALITY PARAMETERS: GARDEN NASTURTIUM (TROPAEOLUM MAJUS L.)'S LEAVES

摘要

This research aims to detect the variations in quality of garden nasturtium's leaves in following growing seasons. Research was conducted out in greenhouse for the late summer-early autumn (August, September, October) and the late spring-summer (May, June, July) growing period in Turkey (40°97' N, 27°51' E). Results presented subsequent morphological properties for the leaves: area (61.36 mm~2), length (28.27 mm), average width (2.37 mm), maximum width (3.97 mm), thickness (0.40 mm), mass (93.63 g) and moisture (0.90 w.b.) were found greater in values for the late spring-summer than the late summer-early autumn season. The season affects the dry matter ingredients, which were greater in the late spring-summer than late summer-early autumn growing season. It was 11.49 in the late summer-early autumn and 13.27 in the late spring-summer growing period. Protein content of the plants for the late summer- early autumn (26.39) was greater than the late spring-summer (21.19) growing period. Sowing time decision significantly affects ascorbic acid ingredient which was 43.29 mg.100~(-1)g in the late summer-early autumn and 38.65 mg.100~(-1)g in the late spring-summer growing period. The values for the terms L, a, and b were assessed as 20.70; -6.41; and 7.79 in the late summer-early autumn and 28.54; -7.23; and 8.52 for the late spring-summer period respectively. Sowing time significantly affects color properties ingredient as well and the record for the late spring-summer was found higher than the late summer-early autumn growing time. Mineral ingredients were measured as N (4.73), P (0.67), Ca (2.38), Cu (10.24 ppm), Fe (971.36 ppm), and Zn (59.98 ppm) and these values were higher in the late summer-early autumn period, however, K (4.49), Mg (0.46), and Mn (63.28 ppm) ingredients were higher in the late springsummer period. The findings reflected that changing weather conditions also affect garden nasturtium. Owing to its relatively easy growing conditions and nutritive value, it provides a good alternative product for the late spring-summer period in greenhouses.