fundamental physiological responses. Temperatures below 15 °C for the first 24 h after application prevent fruit loosening ( Yuan and Burns, 2004 ). When applied by soil drenching, CMNP can cause typical herbicide-like phytotoxic symptoms on leaves of various
Kuo-Tan Li, Jacqueline K. Burns, and James P. Syvertsen
Shital Poudyal and Bert M. Cregg
of insecticides in retention ponds has the potential to induce phytotoxicity. Fungicides . Nursery managers often apply various fungicides to protect crops from a wide range of fungal diseases. Although fungicides may be effective at controlling
Amber N. Bates, Gerald M. Henry, and Cynthia B. McKenney
phytotoxicity concerns associated with many postemergence herbicides make preemergence herbicide applications even more important. Few research trials have focused on the phytotoxic effect of preemergence herbicides on evening primrose species. Richardson and
Mitchell Eicher-Sodo, Robert Gordon, and Youbin Zheng
) leaves ( Copes, 2009 ). Consistent dosing of water with H 2 O 2 leads to the exposure of crops to H 2 O 2 during irrigation events and brings the potential for a phytotoxic response if excessive concentrations are circulated. Exposure of crops to H 2 O
, as were their replicates. The total incubation experiment lasted for 31 d. Growth parameters measurements Percent RWC, percent phytotoxicity, SVI, and TI. For RWC analysis, plants were separated into roots and shoots. Wet plant biomass [fresh weight
Amir M. González-Delgado and Manoj K. Shukla
.). Soil samples collected on 5 Feb., 21 Mar., and 5 May 2016 (45, 90, and 135 d after application) were analyzed for indaziflam as well as indaziflam breakdown products. The trees were visually evaluated for phytotoxicity effects during their dormant and
Joyce G. Latimer and Ronald D. Oetting
Four-week-old salvia (Salvia splendens F. Sellow `Red Pillar') seedlings were treated with 0 or 50 ppm paclobutrazol, followed 5 h later by 0, 1, 2, or 4 times (0×, 1×, 2×, or 4×, respectively) the recommended label rate of bendiocarb (0.6 g a.i./liter), a carbamate insecticide. Seven days after treatment (DAT), phytotoxicity ratings increased with bendiocarb rate on all plants, but 50 ppm paclobutrazol reduced damage at 1× and 4× bendiocarb. Paclobutrazol also improved plant recovery from phytotoxicity damage at 21 DAT. Bendiocarb decreased the height of plants not treated with paclobutrazol at 7, 14, and 21 DAT. Plants treated with 40 ppm paclobutrazol had lower maximum phytotoxicity damage at 14 DAT, and even better recovery at 21 DAT than plants treated with 20 or 60 ppm paclobutrazol. Plants treated with paclobutrazol 4 days before applying bendiocarb had lower maximum phytotoxicity ratings relative to controls than plants treated 8 days before, the same day as, or 4 days after bendiocarb application. Chemical names used: β- [(4-chlorophenyl)methyl]- α -(1,1-dimethylethyl)-1 H- 1,2,4-triazole-1-ethanol (paclobutrazol); 2,2-dimethyl,1,3-benzodioxol-4-yl-methylcarbamate (bendiocarb).
F. C. Waltz and Ted Whitwell
Herbicides can runoff during storms or irrigation and contaminate ponds that are used for irrigation. Overseeded turf areas are particulary vulunerable to low concentrations of herbicides in irrigation water. A greenhouse study was conducted to determine the phytotoxic concentration of simazine in irrigation water perenial ryegrass (Lolium perenne), creeping bentgrass (Agrostis palustris), and fine fescue (Festuca rubra). Irrigation of 6.5 mm of herbicide contaminated and uncontaminated water was applied to seeded pots during a six week period. Concentrations of water containing simazine levels of 0.0001. 0.01, 0.1 and 1.00 ppm were used. Visual injury and number of live seedlings were evaluated every seven days after the beginning of the treatments and a threshold concentration was determined. An immunoassay kit was evaluated for practicality to the golf industry. Species varied in their response to simazine concentrations and immunoassay diagnostic kits have potential for use in detecting phytotoxic simazine concentrations.
Youbin Zheng*, Linping Wang, Weizhong Liu, John Sutton, and Mike Dixon
Copper is one of the essential micro-nutrient elements for plants, but when in excess, is toxic to plants and other living organisms. Electrolytically generated copper and cupric sulphate are increasingly used by the greenhouse industry to control diseases and algae in hydroponic systems. However, there is little information regarding appropriate strategies for employing copper in greenhouse crop production. We investigated the physiological responses, growth and production of several ornamental crops (miniature rose, chrysanthemum and geranium) and greenhouse vegetable crops (pepper, cucumber, and tomato) with respect to Cu2+ concentration in the root zone. Tests were conducted using plants grown in nutrient solution, Promix and rockwool. Results showed that phytotoxic levels of Cu2+ were dependent on the crop species and growing substrate. Plants grown in nutrient solution exhibited symptoms of phytotoxicity at lower Cu2+ concentrations than those on the solid substrates. The ability of copper to control Pythium aphanidermatum and green algae was evaluated under both laboratory and greenhouse conditions. Copper was effective in suppressing green algae in nutrient solution, but did not control Pythium effectively. This presentation is a comprehensive summary of the research conducted over the last three years by our group on copper application in greenhouse systems.
Youping Sun, Guihong Bi, Genhua Niu, and Christina Perez
paclobutrazol at 60 mg·L −1 were effective for height control and lateral branching ( Hilgers et al., 2005 ). Symptoms of phytotoxicity are a known issue with most plant growth retardants. The severity of phytotoxicity depends on plant species or cultivar and