Effect of Daytime Heating on Fruit Yield during Winter Season in Forcing Culture of Tomato

Abstract

Daytime temperatures in the greenhouse are often lower than the suitable growth temperature for forcing culture of tomato in Fukuoka. The effect of daytime heating on the marketable fruit yield during the winter season was investigated in this study. An increase of the minimum day temperature from 8°C to 20°C by a heater resulted in a significant increase of the number of marketable fruits, by improvement of the marketable fruit rates and intervals between anthesis and fruit ripening. In addition, fruit growth after flowering was accelerated when tomato plants were heated in the daytime. It was assumed that photosynthesis of the leaves accelerated, and translocation to fruit increased due to the rising air temperature. As a result, the marketable fruit yield on daytime heating was larger than in the control from April to May.