Further Studies on Vegetative and Fruiting Responses of Tomatoes to High Temperature and Light Intensity

Abstract

1. This paper reports the continuation of the studies begun in 1951 on the influence of high temperature and high light intensity on the vegetative and fruiting responses of tomatoes. 2. Marglobe and Rutgers plants transplanted prior to the period of high temperature-high light intensity fruited normally only before the occurrence of unfavorable temperature and light conditions, while those transplanted directly into the conditions of high temperature-high light intensity grew slowly but did not fruit. 3. Marglobe and Rutgers plants in the field did not respond to sprays of parachlorophenoxyacetic acid (CPA) during the unfavorable light-temperature period, whereas summer-setting varieties and selections cluster-sprayed with CPA nearly doubled their fruit production. 4. Shaded Marglobe and summer-setting varieties had a significantly greater stem height than unshaded plants. Shading or defoliation alleviated light inhibition of the growth rate. 5. Dormancy of fruits of the S-616 variety can be attributed p...