Abstract
Effects of temperature, phytohormones, and light on the coloring of fruit were examined in sweet pepper (Capsicum annuum L). Although coloring was promoted at 20 to 25°C in the dark, the fruit reached only a pale red. In addition, reduction in the chlorophyll content was retarded not only below 10°C, but also above 30°C, yielding dark-colored fruit. Changes in the color were not promoted when either ethylene or methyl jasmonate was applied under a dark condition. Although the color value increased when both phytohormones were simultaneously applied, the effects were insufficient for the force-ripening of fruit. On the other hand, irradiation with a fluorescent light under 20°C markedly promoted the coloring of the fruit. The fruit achieved a bright red color more quickly with a higher irradiance (200 µmol quanta・m-2・s-1). These results indicate that light irradiation plays an important role in the coloring of sweet pepper fruit at an optimal temperature.
