Effects of High and Low Temperature Conditions on the Fruit Setting and Growth of the Parthenocarpic Tomato ‘Renaissance’

Abstract

Effects of high and low temperature conditions in greenhouse on the fruit setting and growth of the parthenocarpic tomato ‘Renaissance’ were examined. Under high temperatures with a mean peak daytime temperature of 39.2°C, the fruit setting rate of ‘Renaissance’ was 100%, and there were no undergrown fruit due to the steady expression of parthenocarpy. At the same condition, the non-parthenocarpic tomato cultivar ‘Momotaro york’ was not able to fertilize, and the fruits did not develop normally without treatment using 4-chlorophenoxy acetic acid (4CPA). Furthermore, under low temperatures with a mean daytime low of 5.9°C, the fruit setting rate of ‘Renaissance’ was 100%, and there were no undergrown fruit due to the steady expression of parthenocarpy. Under the same condition, ‘Momotaro york’ fertilized imperfectlly, the incidence of undergrown fruit was 61%, and treatment with 4CPA was necessary to achieve normal fruit development. It was suggested that the productivity of ‘Renaissance’ was higher than that of the non-parthenocarpic tomato cultivar because the fruits of ‘Renaissance’ developed normally without pollination and the synthetic auxin treatment under high and low temperatures as in this experiment.