Effects of Photoperiod and Temperature on Vegetative and Reproductive Responses of Lycopersicon esculentum Mill.1

Abstract

The responses of five tomato cultivars to photoperiod × temperature were determined under phytotronic conditions. Leaf nodes, subtended between the cotyledons and first inflorescence of ‘Epoch’ and ‘Michigan-Ohio Hybrid’ were significantly reduced by short photoperiod (9 hours) and 22° (day)/18°C (night) temperature. Flower number in these two cultivars was increased by short photoperiod. Days to first anthesis were decreased by short photoperiod and 26°/22° temperature in four out of the five cultivars when compared to long photoperiod (9 hr + 3 hr dark interruption) and 18°/14° temperature.