The Effect of Early Low Temperature Treatment on the Yield of Single-Inflorescence Tomatoes

SummaryA short period at an average temperature of 10° C. during the early growth of tomato plants increased the number of flowers on the first inflorescence. The yield of these plants, whose vegetative apex was removed after the first inflorescence, was approximately 25% greater than that of similar unchilled controls. Fruit number was increased still more ; average fruit weight diminished, and there were fewer very large fruit of low market value. Similar increases in yield were obtained from plants sown throughout the year, except from a September sowing when there was no increase. Chilling delayed harvesting by about four days with summer sowings and rather more in winter, but had little effect on the duration of the harvesting period.Increase in flower number may not have been the only cause of the increased yield. The possibility of a direct effect of the cool period on yield is discussed.The cultivar Minicraigella was more suitable than Minipotella for growing as a single-inflorescence plant since it produced fewer oversize fruit and the fruit ripened more quickly.