Effect of Day Temperature on Occurrence of Blotching on Fruit Surface in Forced Culture of Tomato

Abstract

Blotching on the fruit surface, occurring due to the appearance of vascular bundles on the surface with low-level firmness, is an unfavorable character of tomato. The effect of the day temperature on the appearance of blotching on the fruit surface was investigated in this study. When tomato plants were cultivated in a phytotron with day temperatures of 20, 24, and 28°C under the same night temperature of 8°C, the degree of fruit blotching was severe under a day temperature of 20°C. The values of the blotching intensity decreased as the day temperature increased from 20 to 28°C. To apply the results to actual tomato production, tomato plants were grown in a greenhouse. An increase of the minimum day temperature from 8°C to 20°C with a heater led to a significant decrease of the appearance of blotching on the tomato fruit surface, and resulted in a thick fruit skin and high-level firmness.