Search Results

You are looking at 1 - 10 of 51 items for :

  • Refine by Access: All x
Clear All
Free access

Dong Sik Yang, Svoboda V. Pennisi, Ki-Cheol Son, and Stanley J. Kays

negative effect on indoor air quality ( Darlington et al., 2000 ). VOCs are generally classified as aromatic hydrocarbons (e.g., benzene, toluene, ethylbenzene, xylene), aliphatic hydrocarbons (e.g., hexane, heptane, octane, decane), halogenated

Free access

Mung Hwa Yoo, Youn Jung Kwon, Ki-Cheol Son, and Stanley J. Kays

Foliage plants of Hedera helix L. (english ivy), Spathiphyllum wallisii Regal (peace lily), Syngonium podophyllum Schott. (nephthytis), and Cissus rhombifolia Vahl. (grape ivy) were evaluated for their ability to remove two indoor volatile organic air pollutants, benzene and toluene. Removal was monitored when the aerial portion of plants was exposed singly to 1 μL·L-1 or to 0.5 μL·L-1 of each gas in a closed environment over 6-hour periods during the day and the night. Selected physiological processes were assessed before and immediately after treatment to determine the effect of the gases on the plants. The effectiveness of plants in the removal of air pollutant(s) varied with species, time of day, and whether the gases were present singly or as a mixture. When exposed to a single gas, S. wallisii, S. podophyllum, and H. helix displayed higher removal efficiencies (ng·m-3·h-1·cm-2 leaf area) of either gas than C. rhombifolia during the day. The efficiency of removal changed when both gases were present; H. helix was substantially more effective in the removal of either benzene or toluene than the other species, with the removal of toluene more than double that of benzene. When exposed singly, the removal of both compounds was generally higher during the day than during the night for all species; however, when present simultaneously, H. helix removal efficiency during the night was similar to the day indicating that stomatal diffusion for english ivy was not a major factor. The results indicated an interaction between gases in uptake by the plant, the presence of different avenues for uptake, and the response of a single gas was not necessarily indicative of the response when other gases are present. Changes in the rates of photosynthesis, stomatal conductance, and transpiration before and after exposure indicated that the volatiles adversely affected the plants and the effects were not consistent across species and gases. Deleterious effects of volatile pollutants on indoor plants may be critical in their efficacy in improving indoor air quality and warrant further study.

Free access

Na Liu, Baoli Zhou, Xin Zhao, Bo Lu, Yixiu Li, and Jing Hao

grafted eggplant was different from not only the eggplant scion, but also from the tomato rootstock. Ten classes of compounds were detected in the root exudate from grafted eggplant, including hydrocarbon, benzene and benzene derivative, indene, ester

Free access

Creighton K. Thomas, Kwang Jin Kim, and Stanley J. Kays

mathematical model that assesses the effect of plants on removal of VOCs in buildings. To model removal of VOCs from buildings by potted plants and their associated microbes, we describe the concentration ρ of a single VOC (e.g., benzene) as a function of the

Free access

Natta Laohakunjit, Orapin Kerdchoechuen, Frank B. Matta, Juan L. Silva, and William E. Holmes

characterized. Ethyl acetate (29.30%), acetaldehyde (21.62%), benzyl alcohol (11.93%), and 2-butenyl benzene (7.37%) were the major compounds in fresh samples and acetaldehyde (49.22%) and acetaldehyde (33.31%) were the main compounds in heated fresh sapodilla

Free access

Clyde L. Elmore, Lawrence R. Costello, and W. Douglas Hamilton

Cider gum (Eucalyptus gunnii Hook. F.), Monterey pine (Pinus radiata D. Don), and camphor tree [Cinnamonium camphora (L.) J. Presl] were evaluated in a field study comparing the effects of herbicides on tree growth. Trees were planted on 13 May 1983 and treated on 20 May 1983, 10 Apr. 1984, and 4 Oct. 1984 with simazine, oryzalin, napropamide, and oxyfluorfen. Glyphosate was applied as a postemergence treatment in all basins on 20 Mar. 1984. None of the herbicides injured the trees. Trunk circumferencesin treated plots increased as much as 553% over untreated plots. All species showed a positive response to increasing weed control. Chemical names used: 6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine (simazine); 3,5-dinitro-N4,N4-dipropylsulfanilamide (oryzalin); N,N-diethyl-2-(1-naphthalenyloxy)-propanamide (napropamide); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); N-(phosphonomethyl)glycine (glyphosate).

Free access

Joseph DeFrank and Charles R. Clement

Pejibaye (Bactris gasipaes Kunth, Palmae) is being evaluated for production of fresh heart of palm in Hawaii. Precocity, yields, and weed control were evaluated in response to woven black polypropylene mat (control), oryzalin, oxyfluorfen, and paraquat. Control plots attained 100% of plants harvested by 26 months, followed by oxyfluorfen (97.5%), oryzalin (77.5%), and paraquat (60%). Estimated heart of palm yields (3731 plants/ha) were similar with oxyfluorfen 1.2 kg a.i./ha (707 kg·ha–1), polypropylene mat (612 kg·ha–1), oxyfluorfen 0.6 kg a.i./ha (600 kg·ha–1), and oryzalin 4.5 kg a.i./ha (478 kg·ha–1). Based on precocity, yields, and weed control efficiency, the performance rating of these weed control treatments was mat ≈ oxyfluorfen > oryzalin > paraquat. Chemical names used: 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); 1,1′-dimethyl-4-4′-bibyridinium ion (paraquat).

Free access

Bonnie L. Appleton and Jeffrey F. Derr

Disks of several geotextiles, paper, fiberglass, and black polyethylene were compared with the herbicides oxyfluorfen plus pendimethalin, oxadiazon, and oryzalin plus benefin for suppression of weed growth around container-grown Southwestern white pine (Pinus strobiformis Engelm.), Chinese pistache (Pistacia chinensis Bunge.), and `Fashion' azalea [Rhododendron indicum (L.) Sweet × `Fashion']. The greatest weed control was obtained with a combination geotextile-preemergence herbicide (trifluralin) disk, indicating a possible new method of container weed control. Several of the barrier materials, including heavy wrapping and compressed peatmoss papers, black polyethylene, and one spunbonded geotextile, were inferior due to degradation or to weeds growing around the disk edges or center hole. No difference in crop growth was noted among the treatments. Chemical names used: 2-chloro-1- (3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); N-(1-ethylpropyl)-3,4 -dimethyl-2,6-dinitrobenzenamine (pendimethalin); 3-[2,4-dichloro-5 -(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); 4-(dipropylamino) -3,5 -dinitrobenzenesulfonamide (oryzalin); N-butyl-N-ethyl-2,6 -dinitro-4-(trifluoromethyl) benzenamine (benefin); 2,6-dinitro-N,N-dipropyl-4-(ttifluoromethyl)benzenamine (trifluralin).

Free access

Michelle L. Infante and Ronald D. Morse

Experiments were conducted with `BigSur' broccoli (Brassica oleracea L. var. italica) at two sites in Fall 1993 and at two sites in Spring 1994 on a Hayter loam in southwestern Virginia. Our objectives were to determine the effects of tillage main plots (conventional tillage = CT and no tillage = NT) and weed control subplots [no overseeding or preemergent herbicide, oxyfluorofen, red clover (Trifolium pratense L.), `Dutch' white clover (Trifolium repens L.), and hairy vetch (Vicia villosa Roth)] on broccoli yield and weed suppression. In all sites, weed suppression and marketable broccoli yield with NT were equal to or higher than with CT. Overseeded legume living mulches did not affect broccoli yield in any site compared to the control plots and suppressed weeds as well as the oxyfluorofen in three of the four sites. Thus, the NT systems used in these experiments can suppress weeds and produce high broccoli yields. Also, overseeded legume living mulches can be established effectively after transplanting to suppress weeds without reducing broccoli yield. Chemical name used: 2-choro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorofen).

Free access

Kassim Al-Khatib, Carl Libbey, and Sorkel Kadir

Broadleaf weed control with trifluralin, oxyfluorfen, pendimethalin, clopyralid, pyridate, and metolachlor in cabbage (Brassica oleracea L.) grown for seed was evaluated. No single herbicide controlled broadleaf weeds adequately, with the exception of pendimethalin at 1.92 and 3.84 kg a.i./ha. However, combinations of trifluralin + oxyfluorfen, pendimethalin + clopyralid, and oxyfluorfen + pyridate effectively controlled weeds and did not reduce seed yields. Herbicides caused slight to moderate injury symptoms to cabbage plants, with the greatest injury caused by pendimethalin and the least by trifluralin and metolachlor. However, plants recovered from these symptoms and appeared normal at the bud stage. None of the herbicides applied alone or in combinations adversely affected cabbage population, height, or flowering date. Chemical names used: 3,6-dichloro-2-pyridinecarboxylic acid (clopyralid); 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (oxyfluorfen); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); O-(6-chloro-3-phenyl-4-pyridazin-yl)S-octylcarbonothioate (pyridate); 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine (trifluralin).