Effect of Soil Water Deficit on Coloring and Carotene Formation in Fruits of Red, Pink, and Yellow Type Cherry Tomatoes

Abstract

The effect of soil water content on fruit coloring and carotene formation of fruit was examined using four cherry tomatoes 'Mini Carol' (fruit color: red type), 'Cherry Pink' (pink type), 'Yellow Carol' (yellow type), and 'Orange Carol' (yellowish tangerine type). The soil water deficit treatment hastened the fruit coloring in the spring and fall croppings of 'Mini Carol' and in the fall cropping of 'Cherry Pink'. In most cultivars, pigmentation was advanced by soil water deficit because the color hue angle of the tomato was lower, and/or, their chroma was higher than that of control treatment. Soil water deficit on the fruit coloring was more effective in the fall cropping than it was in the spring, except for 'Orange Carol' which was unaffected by the treatment in spring or fall cropping. On the red and pink type tomatoes, total carotene per fresh weight of fully ripe fruit was increased by soil water deficit; moreover, the ratio of lycopene per colored carotene content was higher than that of the control treatment. Soil water deficit increased the amount of β-carotene per fresh weight of 'Yellow Carol' but it had no effect on β-carotene content in 'Orange Carol' in the spring or fall cropping.