Abstract
The radish cv. Cherry Belle was exposed to 5 pphm ozone and/or 5 pphm sulfur dioxide for 40 hr per week for 5 weeks and compared with controls grown in charcoal filtered air. Ozone and/or sulfur dioxide significantly reduced the plant fresh wt, leaf fresh wt, root fresh and dry wt and root length and width. The effects of the combinations of the 2 gases were additive except for plant fresh wt, root length and root fresh and dry weights where the effects were significantly less than additive. Low concns of ozone and sulfur dioxide can be significant factors in the growth and yield of radishes.
Abstract
Three separate experiments were conducted in a mature Vitis labruscana Bailey ‘Concord’ vineyard in New York to determine the response of grapevines to daily, season-long sulfur dioxide (SO2) exposure, or to intermittent SO2 exposure simulating emissions from a 1700 MW coal-fired power plant. There was little SO2-induced necrosis on grape foliage from daily or power plant SO2. However, both treatments in ambient air increased susceptibility of leaves to oxidant stipple injury due to ambient ozone (O3). Daily SO2 increased leaf chlorosis. Power plant SO2 had no effect on vine growth, yield, or shoot maturation. Daily SO2 reduced soluble solids, growth, yield, and shoot maturation of grapevines. Damage to grapevines from SO2 seemed to be independent of SO2 induced leaf necrosis. SO2 reduced foliage tolerance to O3 injury in grapevines already stressed by ambient O3.
Abstract
Thirty-nine cultivars of marigold (Tagetes spp.) were exposed to sulfur dioxide to determine their relative sensitivity. Flowering plants were fumigated at 1 ppm SO2 for 4 hours or at 2 ppm SO2 for 2 hours. The average foliar injury for all leaves on individual plants ranged from 42.3% for ‘Crackerjack Mix’ at 2 ppm SO2 to 0.0% for ‘Cupid Yellow’ at 1 ppm SO2. Foliar necrosis appeared as a gray to white marginal and/or interveinal scorch 1 day after exposure. There was a tendency for interveinal necrosis to be near the midvein. The extra-floral nectaries which line the leaf margins of marigold were scorched in 15 of the 39 cultivars. This injury may be of diagnostic value. Sepals were very sensitive to SO2. Sepal injury appeared as a pinpoint scorch and as tip burn, and was apparent in some cultivars when no foliar injury occurred.
Abstract
Excised shoots of 10 shade tree species were exposed for 6 hours to 40 pphm (vv−1) sulfur dioxide (SO2), 40 pphm nitrogen dioxide (NO2), or 25 pphm ozone (O3) separately or in mixture. Sorption rates were generally greater in coniferous than in deciduous shoots and higher for SO2 than NO2. Adsorption on leaf surfaces was greater than absorption through stomates for 4 of 5 species in which the 2 forms of sorption could be separated, while sorption from single gases was similar to that from mixed gases for these species. For the 5 species in which transpiration continued in darkness, sorption from the mixture was consistently less than from single gases.
Abstract
No appreciable signs of phytotoxicity were observed for 4 days following fumigation of plants (including begonias, petunias, snapdragons) with ozone of up to 80 parts per hundred million (pphm) or sulfur dioxide of up to 400 pphm for 2 hr. Thereafter, there was considerable necrosis, particularly on begonias fumigated with the highest concn of the pollutants. Growth suppression was reflected in reduced shoot and flower wt, and to a lesser degree in reduced flower number. Overall, begonias and petunias were the most sensitive. Coleus and snapdragons were moderately sensitive, while marigold, celosia, impatiens and salvia were tolerant. ‘White Tausendschon’ was the most sensitive begonia cultivar while blue-flowered ‘Capri’ was the most sensitive petunia. Mixed color petunias exhibited varying degrees of tolerance. ‘Scarlet Rainbow’ coleus was more sensitive than ‘Pastel Rainbow’. Measurements of growth alterations in plants were found very useful in determining latent forms of air pollutant injury.
Abstract
Eight lines (2 cultivars and 6 selections) of Euvitis grapes in 1982 were stored for 4, 6, 7, and 8 weeks at 0° ± 0.5°C without sulfur dioxide (SO2) generators and for 4, 8, 12, 16, and 20 weeks with SO2 generators in 5.7-liter telescoping, corrugated cardboard shipping containers with polyethylene liners. Grapes stored without SO2 were of poorer appearance after 4 weeks than those stored with SO2 after 8 weeks. After 16 weeks of storage with SO2, 4 of the 8 lines still had appearance ratings similar to those before storage. Overall, good flavor was maintained over 7 weeks without SO2 and over 12 weeks with SO2. During 8 weeks of storage without SO2, 6 of the 8 lines developed 23% to 60% decay. In contrast, 6 of the 8 lines stored with SO2 for 16 weeks developed 3% or less decay. SO2 injury (percentage by number) ranged from 0% to 59% but was judged to be objectionable in flavor or appearance in only 2 instances. All lines stored well for 12 weeks with SO2. Of the 8 lines, ‘Suffolk Red’ was judged to be outstanding. After 20 weeks of storage with SO2, ratings of its appearance and flavor were equal to those before storage; decay was only 3.5%.
Abstract
N-[2-(2-oxo-l-imidazolidinyl)ethyl]-N’-phenylurea, (EDU or ethylenediurea) reduced the sensitivity of petunia plants (Petunia hybrida Vilm.) to ozone when treated with foliar or root applications. For most plants, EDU gave protection from visible injury within 24 hours of its application as a spray or soil drench. It was much more effective than butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) as a protectant from ozone injury. The activity of EDU was unaffected by the addition of a surfactant to the spray solution or soil drench, by day length, light conditions, temperature, and physiological preconditioning of the plants. Protection from injury by ozone lasted for at least 14 days. Furthermore, a concentration of 500 ppm either as a foliar spray of 1 to 2 ml per plant or as a soil drench of 100 ml per 10-cm diameter pot protected an ozone sensitive cultivar, ‘Snow Magic,’ the moderately sensitive cultivars, ‘White’ and ‘Pink Cascade,’ and the least sensitive cultivars, ‘Comanche Improved’ and ‘Sugar Plum’. Treatment with EDU afforded no protection against sulfur dioxide exposure doses which produced acute injury.
Abstract
Eighteen cultivars representing 6 species (Poa pratensis L., Agrostis alba L., Agrostis palustris Huds., Agrostis tenuis Sibth., Festuca rubra Gaud., and Lolium perenne L.) of cool season turfgrass were exposed to 15 pphm ozone for 6 hours daily, 15 pphm sulfur dioxide continuously, 15 pphm nitrogen dioxide continuously, or a mixture of all three at these concentrations for 10 days. The most common symptoms of injury on sensitive cultivars in response to these gases were bleaching and necrosis of leaves with some cultivars exhibiting dark brown necrosis and stippling in response to O3 alone. Cultivars varied in sensitivity to O3 or SO2 from very sensitive to insensitive while few cultivars were sensitive to NO2 alone at the concentration used. Exposure of some cultivars resulted in less leaf area production but no visible injury symptoms, while other cultivars had leaf injury without reduction of area of uninjured leaves. The combined exposure caused more leaf injury and greater reduction in the leaf area production by most cultivars compared with plants exposed to single gases. Exposure to single pollutants could provide inaccurate estimates of turfgrass cultivar sensitivity outdoors where several pollutants may occur simultaneously.
Abstract
Three cultivars of greenhouse-grown apple trees (Malus domestica, Borkh.) were fumigated for single, 4-hour exposures with ozone (O3) and/or sulfur dioxide (SO2) at 0.40 and 0.80 ppm. Fumigations were performed in a plexiglass chamber situated within a controlled environment walk-in growth chamber. All 3 cultivars responded to treatments in a similar manner. When applied separately both gases induced characteristic foliar injury. In general, apple trees were more sensitive to 0.40 ppm O3 than to 0.40 ppm SO2; but they responded similarly to 0.80 ppm O3 or SO2. Foliar injury, leaf abscission, and shoot growth reduction were greatest when 0.80 ppm O3 and 0.80 ppm SO2 were combined. The data showed a less-than additive response when the 2 pollutants were combined; a response due, in part, to the high amount of injury induced by single pollutants at these concentrations. All O3 and/or SO2 fumigations resulted in stomatal closure.
Abstract
Eighteen lines of Euvitis grapes in 1980, and 30 in 1981, were stored for 9 weeks at 0°C in 5.7-liter telescoping, corrugated cardboard shipping containers with polyethylene liners, with and without commercially available sulfur dioxide (SO2) generators (1 in 1980; 2 in 1981). Decay during storage without SO2 varied greatly among lines (2% to 81% in 1980 and 0% to 62% in 1981). The generator producing SO2 for the entire 9 weeks in 1981 eliminated decay of most grape lots. By comparison, the generators producing SO2 for only 2 weeks permitted 4 times as much decay. Two weeks of SO2, however, permitted only one-fifth as much decay as that associated with no SO2 during storage. Both generators reduced degradation of appearance and flavor of the grapes. The long-term generator was associated with more SO2 damage to the fruit than was the short-term generator. The lines varied widely in tolerance to SO2. SO2 damaged the fruit by entering openings in their surfaces caused by stem tears and cracks.