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Open access

P. W. Hildebrandt

Abstract

Air monitoring has become a complex, expensive, and difficult undertaking. Regardless of the problems involved, however, atmospheric pollutant measurement is essential to properly evaluate the air pollution cause and effect relationship.

Open access

David C. MacLean

Abstract

Current interest in air pollution effects on vegetation is derived from 3 basic concerns: economic, aesthetic, and ecologic. The economic concern is an obvious one. Air pollution can result in reduced yield or impaired quality of the harvestable product, either through effects on its appearance, which affect its marketability, or its internal composition that may affect its nutritive value. Commercial losses in horticulture and other agricultural operations due to air pollution amount to hundreds of millions of dollars annually. The esthetic concern, though less pragmatic, also is important. Air pollution can cause foliar symptoms or altered growth that detract from the appearance of native plants in natural areas or ornamental plants in landscaped properties, public parks, and along highways. The third concern has to do with ecologic imbalances caused by air pollution. Vegetation plays an important role in soil and water conservation. It provides food and habitats for wildlife; it is essential for the O2-CO2 balance in nature; and it plays a vital role in the recycling of many elements in the ecosystem. Thus, air pollution directly affects the economic, aesthetic, and ecologic value of plants and these, in turn, directly or indirectly affect the well-being of man.

Free access

W.A. Retzlaff, W.W. Barnett, L.E. Williams, and T.M. DeJong

Japanese plum (Prunus salicina Lindel. `Casselman') trees exposed to three atmospheric ozone partial pressure treatments were sprayed with a summer application of Volck Supreme oil (1% aqueous solution) to control an outbreak of spider mites (Tetranychus spp.). Phytotoxic effects were observed on the foliage of trees in the plots exposed to ambient or higher atmospheric ozone partial pressures 5 days following spray application. Foliage on trees exposed to 0.044 and 0.081 μPa·Pa-1 ozone [12-h mean (8 Apr. to 12 June 1992)] partial pressures developed water spotting and more foliage abscission than trees exposed to charcoal-filtered air (0.024 μPa·Pa-1 ozone). Thus, ozone air-pollution stress may predispose plants to increased phytotoxicity from summer oils.

Open access

J. W. Cameron, Hunter Johnson Jr., O. C. Taylor, and H. W. Otto

Abstract

Marked differential injury by air pollution to a group of sweet corn hybrids in 2 experimental field plantings in the Los Angeles Basin occurred in 1969. At Riverside, leaf damage ranged from nearly zero in 11 hybrids to slight to severe in 23 others. Damage was clearly related to cultivar and was associated with periods of high oxidant levels and high maximum temperatures. There was only a slight relationship between the market maturity date of a cultivar and its degree of damage.

Open access

Gerald L. Klingaman and Conrad B. Link

Abstract

Forty-five chrysanthemum cultivars exposed to ozone in a controlled environment chamber exhibited a wide range of sensitivity with several showing sufficient sensitivity to be damaged by ambient oxidant concentrations. Chemical protection of foliage from ambient air pollution was tested on pollution sensitive ‘King’s Ransom’ and pollution tolerant ‘Yellow Jess Williams’. Chemical protectants included 1) benomyl, 2) thiophanate ethyl, 3) triarimol, 4) ancymidol, 5) SADFI, and 6) Folicote. No visible injury was observed on unprotected ‘Yellow Jess Williams’, but extensive injury occurred on older foliage of ‘King’s Ransom’. Full season protection was observed on ‘King’s Ransom’ receiving treatments of benomyl, thiophanate ethyl or ancymidol but ancymidol delayed anthesis and reduced flower count.

Free access

Dennis Decoteau, Jonathan Ferdinand, Jim Savage, Dick Stevenson, and Donald Davis

Penn State's Air Quality Learning and Demonstration Center was completed and open to the public in 2003. The facility houses the State College air monitors for the Department of Environmental Protection and contains self-guided walkways through gardens of air pollution sensitive plants, innovative techniques for demonstrating the effects of air pollutants on plants, displays of recent research findings, industry-supported displays of pollution abatement technologies, and a teaching pavilion. One of our outreach projects, funded by the US EPA and the PA Department of Environmental Protections, is to provide enhanced teacher training on air pollution impacts on the regional and specific vegetation through an in-service training for local science school teachers utilizing on-site and archived data on weather conditions and plant injury symptom development. The picture archive began to be developed during Summer 2005 using video cameras that are permanently mounted for the growing season inside the open-top chambers and focused on a plant (and a specific leaf or set of leaves). Once the teachers are trained to utilize these data sets appropriately, they will be able to access the data during the school year through the Learning Center website and conduct the same analysis with their students in their classroom during the school year. This use of archival information is important because the school year does not coincide with optimum times for observing air pollution symptoms on vigorously growing field-grown plants in Pennsylvania (which is best during the summer).

Open access

Walter J. Kender, E. F. Taschenberg, and N. J. Shaulis

Abstract

Methyl 1-butyl-carbamoyl-2-benzimidazole carbamate (benomyl) as a dilute foliar spray reduced atomspheric oxidant injury (oxidant stipple) on ‘Ives’ and ‘Concord’ grapevines (Vitis labrusca L.) in 3 vineyard experiments in 1972. Three to 7 multiple applications at 1.12, 3.36, and 6.72 kg/ha increased the protection over unsprayed ‘Concord’ vines. Single and double applications were ineffective. The degree of protection afforded was directly related to the frequency of benomyl application.

Open access

D. P. Ormrod and N. O. Adedipe

Abstract

Observation of vegetation injury induced by exposure to air pollutants provides a simple and low cost means of monitoring pollutant emissions from a particular source as well as for determining the distribution of pollutants over a wide area. This use of plants has long been accepted and has been extensively reported (2, 7, 8, 14). However, many other environmental factors may also cause plant injury and their effects are often difficult to distinguish from pollution-induced damage (13). In addition, factors such as temperature, humidity, wind velocity, light, nutrition, water supply, and the presence of pesticides and other chemicals have all been shown to markedly influence plant sensitivity to air pollutants.

Open access

Walter J. Kender and Philip L. Forsline

Abstract

Air pollution research on vegetation has progressed rapidly in the last decade. As a result, our understanding of the effects of pollutants on horticultural crops generally is well documented. Our knowledge of the mode of action of air pollutants injuring plants, however, is much less known. It is difficult to devise practical control methods without such understanding.

Free access

Atilla B. Goknur and Theodore W. Tibbitts

The magnitude of dark opening of stomata on leaves of Irish potato (Solanum tuberosum L.) was studied to determine if this opening was related to the high sensitivity of these plants to air pollutants. Stomatal opening was studied over diurnal periods both in the field and in controlled environments. In both environments, stomatal conductance decreased rapidly at the initiation of dark to 0.1 cm·s-1 but then increased to 0.2 cm·s-1 over the dark period. However conductance was always less in the dark than in the light (0.3 to 0.9 cm·s-1). During the early part of the dark period, stomatal conductance in controlled environments was not as great as in the field, but conductance was similar in both environments over the latter part of the dark period. Cultivars Norchip and Kennebec had smaller conductances during the first hours of the dark than Haig or Katahdin, and all cultivars increased in conductance over the dark period. `Haig' showed slightly higher conductance than the other three during the last 4 hours of the dark period. Injury to `Haig' from 3-hour fumigations with sulfur dioxide (SO2) or ozone (O3) demonstrated that exposures during the day generally produced more injury than during the night, although exposures with SO2 during the last 3 hours of the light period produced similar injury to exposures at the end of the dark period. Thus, although partial opening during the dark may be permitting some pollution injury, it is concluded that previous published reports of similar opening of stomata on Irish potatoes during the light and dark periods, and equal or greater pollution injury during the dark compared with the light period, were not substantiated and apparently resulted from procedural artifacts.