1981-1982 NCLAN (National Crop Loss Assessment Network) Program at LLNL: The Effects of Ozone and Sulfur Dioxide, Singly and in Combination, on Field-Grown Tomato

摘要

The combined effects of ozone (O3) and sulfur dioxide (SO2) exposures on tomato (Lycopersicon esculentum Mill.) crop yields were measured during the 1981 and 1982 growing seasons. The effort, part of the National Crop Loss Assessment Network (NCLAN), had the objective of determining the yield dose response of tomato grown under commercial conditions. Dose response was determined using step-wise multiple regression techniques and was expressed as reduction in marketable yield as a function of increased pollutant levels. The crops were harvested during mid-September 1981 and during mid-October 1982. No O3- or So2-induced visible injury symptons (lesions, chlorosis, or becrosis) were apparent on foliage or fruits. Total marketable fruit fresh weight was used as the dependent variable in the regression analysis because it most closely represented the economic value of the crop. Comparison of chambered- and companion-plot data showed that the chambers themselves caused significant effects on the crop. Yields were reduced 12% in 1981 and 24% in 1982 due to the chambers. There was also more unripened fruit within the chambers because of chamber-induced uneven distribution of an aerially-applied ripening agent. Dose-response results were independent of the chamber effects. Based on companion-plot data, the yield of the crop in the research area was 65 + or -2 Mg ha sup -1 in both years. The research-area yields correlated well with those from the adjacent commercial plantation. With respect to tomato production in the San Joaquin Valley, we recommend that an air quality management strategy be adopted to contain ambient O3 concentrations at or below present levels. Containment at present levels would avoid O3-induced tomato yield reductions greater than 7%, even during atypical years such as 1982. 26 refs., 17 figs., 9 tabs. (ERA citation 13:047300)