Leachates were produced by washing Hydra-fill, a polyurethane ester foam, with water. These leachates decreased radish (Raphanus sativus L.) and tomato (Lycopersicon esculenturn Mill.) seed germination and were phytotoxic to seedlings. Washing the foam for as little as 5 minutes (compared to not washing) before collecting the leachate significantly decreased the mean seed germination time by 0.6 to 1 day. Rinsing the foam with ethanol before collecting the leachate was detrimental to germination. When used as a potting medium component, the foam reduced radish shoot and root dry weights compared to potting media without foam. Washing the foam with tap water before use resulted in increased radish shoot and root dry weights. Hydra-fill generally reduced plant performance when included in potting media. However, radish grew well in fresh 25% Hydra-fill (raw or washed) mixed with loam.
The granular formulation of pendimethalin (Southern Weedgrass Control) safely provides preemergent control of grasses and broadleaf weeds in a variety of landscape ornamentals but few annuals. The purpose of this experiment was to evaluate phytotoxicity of pendimethalin to several annual species under landscape conditions. Pendimethalin at 1.7, 2.2, 2.8, or 3.4 kg ai/ha was applied over-the-top to cool and warm season annuals in a simulated landscape at 4-month intervals starting 15 October 1990. The simulated landscape was divided into 4 blocks (reps) with pendimethalin levels as the main plot factor and annual species as the subplot factor. Unweeded and hand-weeded plots served as controls. Irrigation (over-the-top) and insecticides were applied on an as-needed basis. All annuals except `Sonnet Burgundy' snapdragon exhibited some degree of stunting. `Vodka' wax begonia was the most sensitive to pendimethalin as it was moderately stunted at all rates. Weed control generally was good to excellent.
Benzimidazoles are effective and widely used fungicides, but they may be phytotoxic. We studied the effects of a single drench application of six benzimidazoles and one acetanilide fungicide on photosynthetic gas exchange, growth, development, and nutrient levels of four species of bedding plants in twenty growth-chamber and four greenhouse studies. Daily carbon gain and carbon-use efficiency were calculated from continuous crop gas-exchange measurements in the growth chambers. The maximum labeled rate of Benlate DF caused a 7- to 10-day decrease in net photosynthesis and daily carbon gain in transplants of all species. It also caused pronounced interveinal chlorosis and a 2- to 3-day delay in flowering. Growth of Benlate DF-treated plants was reduced more at high (90%) than at low (60% to 80%) relative humidity. Benlate DF had severe effects on 2-week-old petunia (Petunia ×hybrida) seedlings in plug flats, reducing photosynthesis 25% to 57%. Cleary's 3336 WP decreased photosynthesis in some trials. Benlate DF reduced photosynthesis within 24 hours, but 3336 WP effects did not become apparent until 1 week after the treatment. This suggests different modes of inhibition. 3336 WP also caused leaf-tip and marginal chlorosis in impatiens (Impatiens wallerana). Mertect 340-F was extremely phytotoxic but is not labeled for drench applications (it was included because of its chemical similarity to other benzimidazoles). The only benzimidazole fungicide that did not reduce photosynthesis was Derosal, but it caused slight interveinal chlorosis in some studies with petunia. Benlate DF and Derosal decreased leaf Ca levels. Subdue (or metalaxyl), an acetanilide fungicide, did not affect photosynthesis or cause any visual symptoms. Our results indicate that some benzimidazole fungicides can cause growth reductions and visual damage in bedding plants.
, 1974 ; Pilbeam and Bell, 1979 ) that was demonstrated to be phytotoxic, inhibiting hypocotyl and radicle growth during germination ( Wilson and Bell, 1979 ). Nonprotein amino acids from other legumes also have been shown to be phytotoxic. These include
Three watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] cultivars with different ozone (O3) sensitivities were grown in a charcoal-filtered greenhouse and exposed in continuous-stirred tank reactor chambers to five levels (0, 100, 200, 300, or 400 nL·L-1) of sulfur dioxide (SO2) in the presence (80 nL·L-1) or absence (0 nL·L-1) of ozone (O3) for 4 hours/day, 5 days/week for 22 days. In the presence of O3, SO2 increased foliar injury in all three cultivars, but the impact was greatest for the most O3-sensitive cultivar, `Sugar Baby,' moderate for `Crimson Sweet,' and least for the least O3-sensitive cultivar, `Charleston Gray.' For all cultivars, SO2 intensified O3 suppression of leaf area for the first seven mainstem leaves and of dry weights for aboveground and total plant tissues. Root dry weight was independently suppressed by both pollutants, and the root: top ratio was linearly suppressed by SO2 alone. Sulfur dioxide combined with O3 can be detrimental to crop species such as watermelon. Thus, the potential for SO2 phytotoxicity should not be summarily dismissed, especially in the vicinity of SO2 point sources where O3 co-occurs.
Abstract
Fruit of cherry (Prunus avium L.) and banana (Musa sp.,) AAA Group, Cavendish sub-group cv. Williams Hybrid, when fumigated with ethylene dibromide (EDB) and held at 20°C were injured visibly by treatment concentrations of 32 g/m3 or more. EDB (4 g/m3) stimulated the rates of both ethylene (C2H4) evolution and respiration in cherries, while higher concentrations up to 32 g/m3 caused proportionately greater increases in the rates of gas exchange. Cherries stored at 1° after fumigation with 32 g/m3 EDB did not display the increases in gas exchange which were observed at 20°, but during a 7 day storage period severe Symptoms of phytotoxicity developed. The increases in gas exchange are, therefore, effects and not causes of EDB injury. The Stimulation of C2H4 production in cherries by EDB was reduced by pretreatment with Co2+, indicating that EDB affects the methionine pathway of ethylene synthesis. In bananas treated with 4 g/m3 EDB and held at 20°, the respiration rate increased but C2H4 evolution and electrolyte leakage from slices of pulp tissue were unaffected. When the EDB concentration was raised to 32 g/m3, respiration and C2H4 evolution rates and electrolyte leakage increased.
concentration experiment was to evaluate the phytotoxicity of ABA application under field conditions and confirm the optimum concentration from the greenhouse study ( Zhang et al., 2011 ). The experiment was conducted at 50% fruit set stage (FS), corresponding
reproductive structures frequently succumb entails phytotoxicity of off-target movement of chemicals against which there are no control measures ( Bondada, 2010 ). These chemicals primarily include vapors and spray drifts of phenoxy herbicides ( Bondada et al
information available on its fate and transport under laboratory and field conditions ( González-Delgado et al., 2017 ; Guerra et al., 2014 ; Trigo et al., 2014 ). Information on phytotoxicity effects of indaziflam on pecan is especially limited ( González
lakes often use water from these sources to irrigate turf, bedding plants, foliage species, and other ornamental plants. Therefore, a study of the possible phytotoxicity of these herbicides is important to determine appropriate irrigation restrictions on