( Aynardi et al., 2011 ; Aynardi and Uddin, 2013a , 2013b ; McCall and Focht, 2010 ; Popko et al., 2010 ; Popko and Jung, 2013 ). Acute and chronic phytotoxicity is a known limitation of PDSOs ( Hodgkinson et al., 2002 ). Acute phytotoxicity results
Abstract
Methomyl insecticide (Lannate 90 wp) was selectively phytotoxic on hybrids and inbreds of sweet com (Zea mays L.) having the Texas male sterile cytoplasm (T-msc). In field and greenhouse tests, phytotoxicity was visible at leaf tips and margins 2 days after a foliar application of 300 ppm methomyl. In the greenhouse, a pre- or postemergence application of methomyl, 75 mg/kg soil resulted in severe necrosis, chlorosis, and eventual death of the seedlings. None of 100 hybrids and inbreds with normal cytoplasm and 4 other different sources of sterile cytoplasm showed any visible injury following a foliar or soil application of methomyl.
many of the harmful chemical residues associated with other treatment technologies (e.g., chlorination). These properties make the technology attractive to horticultural production; however, data are lacking on the phytotoxicity of aqueous ozone
( Fig. 1C ). These barren sites had received no pesticide applications, so observations indicated a phytotoxic chemical legacy may be causal. However, no effort has been made to understand this phenomenon. If scale-infested cycad litter is validated as a
that a chlorine-resistant phytopathogen, Rhizoctonia solani ( Cayanan et al. 2009 ), could be completely inactivated using an EFC with DSAs. This inactivation was achieved by regeneratively releasing concentrations of FC below a reported phytotoxic
, 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
.). 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
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).
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.
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.