Reduction of Tomato Fruit Size and Yield by Ozone1

Abstract

A multiple regression analysis of yields of ‘6718 VF’ tomato (Lycopersicon esculentum Mill.) from 11 field plots along an ambient ozone gradient in southern California indicated that ozone was responsible for a significant reduction in fruit size. Ozone dose accounted for 85% of the reduction in fruit size and was at least 3.3 times more important than any of the monitored meteorological variables in predicting the percentage of marketable fruit. High ambient ozone depressed production and caused a significant decrease in fruit size over time. A model describing the reduction in marketing container yield (% reduction = 0 + (.0232 x dose)) predicted a 50% reduction at a dose of 2000 pphm-hours > 10 pphm.

Quality of Tomatoes Harvested from Plants Receiving Chronic Exposures to Sulfur Dioxide1

“…Tomato plants have exhibited significant reductions in yield in response to the air pol lutant ozone (10,14,15,16). Quality of the fruit harvested from plants exposed to ozone may also be altered.…”

Breeding Vegetables Tolerant to Environmental Stress

“…Several reports describe differences in severity of foliar symptoms among tomato germplasm (7,8,13,24). However, it has not been demonstrated that air pollutants reduce yield or quality of tomatoes (18,21,22,23). Thus a breeder must decide if he should make a concerted effort to select for air pollution tolerance or rely on chance selection for tolerance to ubiquitous pollutants.…”