The Response to CO2Enrichment of Capillary-Watered Single-Truss Tomatoes at Different Plant Densities and Seasons

SummaryCO2 enrichment advanced the date of first anthesis, promoted earlier cropping and shortened the duration of harvest for single-truss tomatoes sown in December and, to a lesser extent, for those sown in July. It also prevented arrested development of the flowers of a December-sown crop growing in poor light.CO2 caused increases in marketable fruit yield that were greatest for a mid- July sowing and least for a mid-December sowing. The increases obtained from plants sown in mid-December were independent of population density. For a mid-July sowing the increases in yield of ripe marketable tomatoes were 33% and 17% at population densities of 10 and 25 plants/m2 respectively. Increases in total marketable fruit weight caused by CO2 resulted from an increase in the number of fruits attaining marketable size and an increase in the average weight of individual fruits.Some of the advantages of producing fruit on single-truss tomatoes grown in shallow capillary-watered beds are mentioned.