A growth chamber study of the effect of soil concentration and plant age on the uptake of Sr and Cs by tumbleweed

1978 ◽  
Vol 9 (3) ◽  
pp. 215-229 ◽  
Author(s):  
R. C. Routson ◽  
D. A. Cataldo
Keyword(s):  
Plant Age ◽  
Growth Chamber ◽  
Soil Concentration ◽  
Chamber Study

Survival ofEscherichia coliO157:H7 in soil and on lettuce after soil fumigation

2007 ◽  
Vol 53 (5) ◽  
pp. 623-635 ◽  
Author(s):  
A.  Mark Ibekwe ◽  
Catherine M. Grieve ◽  
Ching-Hong Yang
Keyword(s):  
Growth Chamber ◽  
Term Survival ◽  
Soil Microcosms ◽  
Long Term Survival ◽  
E Coli ◽  
Chamber Study ◽  
Plate Counts ◽  
Significant Pathway ◽  
Harsh Conditions

Long-term survival of Escherichia coli O157:H7 in soil and in the rhizosphere of many crops after fumigation is relatively unknown. One of the critical concerns with food safety is the transfer of pathogens from contaminated soil to the edible portion of the plants. Multiplex fluorogenic polymerase chain reaction was used in conjunction with plate counts to quantify the survival of E. coli O157:H7 in soil after fumigation with methyl bromide and methyl iodide in growth chamber and microcosm laboratory experiments. Plants were grown at 20 °C in growth chambers during the first experiment and soils were irrigated with water contaminated with E. coli O157:H7. For the second experiment, soil microcosms were used in the laboratory without plants and were inoculated with E. coli O157:H7 and spiked with the two fumigants. Primers and probes were designed to amplify and quantify the Shiga-like toxin 1 (stx1) and 2 (stx2) genes and the intimin (eae) gene of E. coli O157:H7. Both fumigants were effective in reducing pathogen concentrations in soil, and when fumigated soils were compared with nonfumigated soils, pathogen concentrations were significantly higher in the nonfumigated soils throughout the study. This resulted in a longer survival of the pathogen on the leaf surface especially in sandy soil than observed in fumigated soils. Therefore, application of fumigant may play some roles in reducing the transfer of E. coli O157:H7 from soil to leaf. Regression models showed that survival of the pathogen in the growth chamber study followed a linear model while that of the microcosm followed a curvilinear model, suggesting long-term survival of the pathogen in soil. Both experiments showed that E. coli O157:H7 can survive in the environment for a long period of time, even under harsh conditions, and the pathogen can survive in soil for more than 90 days. This provides a very significant pathway for pathogen recontamination in the environment.

scholarly journals Influences of Season and Cutting Week within a Propagation Cycle on Rooting of ‘Stained Glass’ Coleus Shoot Tip Cuttings Are Not Overcome by Rooting Compound Treatment

2016 ◽  
Vol 26 (5) ◽  
pp. 620-627 ◽  
Author(s):  
Brigitte D. Crawford ◽  
John M. Dole ◽  
Ben A. Bergmann
Keyword(s):  
Root Systems ◽  
Adventitious Rooting ◽  
Plant Age ◽  
Growth Chamber ◽  
Stock Plant ◽  
Stained Glass ◽  
Cycle Number ◽  
Solenostemon Scutellarioides ◽  
Plant Environment ◽  
Quality Ratings

Influence of season of the year, cutting week within a propagation cycle (number of weeks from which a stock plant has been harvested), stock plant age, and rooting compound on postpropagation cutting quality, and adventitious rooting was examined for ‘Stained Glass’ coleus (Solenostemon scutellarioides). Cuttings were of higher quality and produced more robust root systems when a propagation cycle started in summer vs. fall or spring even when cuttings were harvested from stock plants of the same age. Cutting week within a propagation cycle significantly influenced postpropagation cutting quality and rooting when cuttings were harvested over many weeks from the same stock plants and when cuttings were harvested for three propagation events using stock plants of different ages. When cuttings were harvested on the same days from stock plants of three distinct ages, cuttings harvested in the first week were larger with greater root weights but had more yellowed leaves and lower quality ratings compared with the two subsequent cutting weeks, but stock plant age had no effect on any observed parameter. Treatment with rooting compound did not overcome the significant influences of season and cutting week within a propagation cycle whether rooting was carried out in a greenhouse or growth chamber. Shoot and root fresh and dry weights were positively correlated with both daylength and midday instantaneous light of the stock plant environment.

Effect of zinc on cadmium concentration in the tissue of durum wheat

1994 ◽  
Vol 74 (3) ◽  
pp. 549-552 ◽  
Author(s):  
M. Choudhary ◽  
L D. Bailey ◽  
C. A. Grant
Keyword(s):  
Ammonium Nitrate ◽  
Durum Wheat ◽  
Key Words ◽  
Triticum Turgidum ◽  
Cadmium Concentration ◽  
Growth Chamber ◽  
Monoammonium Phosphate ◽  
Chamber Study ◽  
Soil Temperatures

The addition of zinc at 20 mg kg−1 to soils in a growth chamber study reduced the shoot Cd concentration of two durum wheat (Triticum turgidum L. var durum) lines at 10 °C, 16 °C, and 22 °C soil temperatures while additions of ammonium nitrate (NH4NO3) and monoammonium phosphate (NH4H2PO4) increased shoot Cd concentrations. Applying Zn with NH4NO3 or NH4H2PO4 reduced shoot Cd concentrations of the plants to levels comparable to the control. Key words: Cd, durum wheat, ammonium nitrate, monoammonium phosphate, Zn

scholarly journals Effect of Benomyl Treatments on Marigold and Indigenous Rhizosphere Bacteria

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 680a-680
Author(s):  
W.A. Bergfield ◽  
D.N. Sasseville ◽  
R.J. Kremer
Keyword(s):  
Plant Growth ◽  
Rhizosphere Bacteria ◽  
Growth Chamber ◽  
Tagetes Patula ◽  
Repeated Application ◽  
Growth Data ◽  
Nontarget Effects ◽  
Chamber Study ◽  
Shoot Mass ◽  
Production Problems

The fungicide benomyl (formulated as Benlate 50 DF) has been implicated in damage to several crops grown under warm, moist conditions. Although the target pathogen may be controlled, occurrence of population shifts in rhizosphere bacteria has been documented, with benomyl application. A growth chamber study to investigate the effects of benomyl on marigold (Tagetes patula) and subsequent effects on the populations of rhizosphere bacteria of marigold was performed. A one pound per one hundred gallon rate as foliar and drench treatments were applied to marigolds. Plant growth data and rhizosphere bacteria populations were recorded. Repeated application of the benomyl treatments significantly reduced the marigold root and shoot mass, 44% and 67% respectively, compared to controls. Repeated foliar applications of benomyl also resulted in necrotic lesions on marigold leaf margins. Rhizosphere bacteria total numbers differed between treatments, having a greater population for the drench rate than the foliar rate. These results suggest application of benomyl may have harmful nontarget effects, leading to production problems associated with its use.

A GROWTH CHAMBER STUDY OF COPPER NUTRITION OF CEREAL AND OILSEED CROPS IN ORGANIC SOIL

1984 ◽  
Vol 64 (3) ◽  
pp. 505-510 ◽  
Author(s):  
D. W. McANDREW ◽  
L. A. LOEWEN-RUDGERS ◽  
G. J. RACZ
Keyword(s):  
Copper Deficiency ◽  
Organic Soil ◽  
Growth Chamber ◽  
Controlled Environment ◽  
Flower Initiation ◽  
Growth Disorders ◽  
Oilseed Crops ◽  
Cu Deficiency ◽  
Chamber Study ◽  
Plant Shoots

Copper nutrition of barley (Hordeum vulgare ’Conquest’), oats (Avena sativa ’Hudson’), wheat (Triticum aestivum ’Neepawa’), flax (Linum usitatissium ’Dufferin’) and canola (Brassica campestris ’Torch’) was studied on a severely Cu-deficient organic soil in a controlled environment growth chamber. The objective of the study was to facilitate identification of Cu-related growth disorders by establishing the critical levels for Cu in plant tissues of the crops listed above. Copper deficiency symptoms were exhibited by all crops when Cu was not applied. Copper concentrations in plant shoots were considered as low when they ranged from 3.0 to 4.9 μg Cu/g plant dry matter (pdm) for wheat, from 2.3 to 3.7 μg Cu/g pdm for barley, from 1.7 to 2.5 μg Cu/g pdm for oats, from 1.7 to 2.7 μg Cu/g pdm for canola and from 2.4 to 3.5 μg Cu/g for flax. The measurements were made at heading for the cereals, pod initiation for canola, and at flower initiation for flax. Concentrations below these ranges were considered deficient and above these ranges sufficient. The order of tolerance to Cu deficiency in the soil was canola>barley>oats>wheat>flax.Key words: Copper nutritional ranges, copper deficiency, mesisol

scholarly journals Morphology, Turf Quality, and Heat Tolerance of Intermediate Ryegrass

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 170-173 ◽  
Author(s):  
M.D. Richardson
Keyword(s):  
Heat Tolerance ◽  
Perennial Ryegrass ◽  
Field Studies ◽  
High Temperature Stress ◽  
Growth Chamber ◽  
Annual Ryegrass ◽  
Greenhouse Study ◽  
Chamber Study ◽  
Chamber Studies ◽  
Growth Chamber Studies

Bermudagrass (Cynodon spp.) turf is often overseeded with a cool-season species such as perennial ryegrass (Lolium perenne L.) to provide an improved winter surface for activities such as golf or athletic events. Perennial ryegrass can become a persistent weed in overseeded turf due to the heat and disease tolerance of improved cultivars. Intermediate ryegrass is a relatively new turfgrass that is a hybrid between perennial and annual ryegrass (L. multiflorum Lam.). Very little information is available on intermediate ryegrass as an overseeding turf. Greenhouse, field, and growth chamber studies were designed to compare two cultivars of intermediate ryegrass (`Transist' and `Froghair') with three cultivars of perennial ryegrass (`Jiffie', `Racer', and `Calypso II') and two cultivars of annual ryegrass (`Gulf' and `TAM-90'). In a greenhouse study, the perennial ryegrass cultivars had finer leaf texture (2.9-3.2 mm), shorter collar height (24.7-57.0 mm), and lower weight/tiller (29-39 mg) than the intermediate and annual cultivars. In the field studies, the intermediate cultivar Transist exhibited improved turfgrass quality (6.1-7.1) over the annual cultivars (4.5-5.8) and the other intermediate cultivar Froghair (5.4-5.7). However, neither of the intermediate cultivars had quality equal to the perennial ryegrass cultivars (7.0-7.9). The perennial ryegrass cultivars exhibited slow transition back to the bermudagrass compared to the annual and intermediate ryegrass cultivars. In the growth chamber study, the annual and intermediate cultivars all showed increased high-temperature stress under increasing temperatures compared to the perennial cultivars, which did not show stress until air temperature exceeded 40 °C. Collectively, these studies indicate that the intermediate ryegrass cultivar Transist may have promise as an overseeding turfgrass due to its improved quality compared to annual types and a lack of heat tolerance relative to perennial cultivars, but with transition qualities similar to perennial ryegrass.

scholarly journals Cool-season Grasses for Overseeding Sport Turfs: Germination and Performance under Limiting Environmental Conditions

HortScience ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Francesco Rossini ◽  
Roberto Ruggeri ◽  
Tiziano Celli ◽  
Francesco Maria Rogai ◽  
Ljiljana Kuzmanović ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Warm Season ◽  
Growth Chamber ◽  
Annual Ryegrass ◽  
Cool Season ◽  
Meadow Fescue ◽  
Greenhouse Study ◽  
Chamber Study ◽  
And Performance

In the transition zone, warm-season grasses are often overseeded with diploid perennial ryegrass (Lolium perenne L., 2n = 2x = 14) to provide a temporary green surface for winter sporting activities. Because improved cultivars of perennial ryegrass will often persist into summer in overseeded turf, alternative cool-season grasses have been developed to facilitate more rapid transition back to the warm-season species. Limited information is available on these alternative species, especially with regard to their germination characteristics under shade and performance under limiting factors, such as low temperature and restricted photoperiod. Greenhouse and growth chamber studies were designed to test four alternative overseeding grasses in comparison with diploid perennial ryegrass, to verify their potential use in the artificial environment of modern stadiums. Meadow fescue (Festuca pratensis Huds.), tetraploid perennial ryegrass (Lolium perenne L., 2n = 4x = 28), annual ryegrass (Lolium multiflorum Lam.), and spreading diploid perennial ryegrass [Lolium perenne L. subsp. stoloniferum (C. Lawson) Wipff.] were tested. Six different shade treatments were used in the greenhouse study, including 30%, 50%, 70%, 90%, and 100% shade and a nonshaded control (0% shade). Germination was monitored daily over a 21-day period by counting and removing emerged seedlings. The experimental design for this study was a randomized complete block design, with four replications of each species and shade level for a total of 120 experimental units. In the growth chamber study, the same plant material was tested simulating optimal, suboptimal, and critical environmental conditions that can be potentially found within a modern sport facility. In the greenhouse study, the highest final germination was observed with annual ryegrass at 90% shade (98.7%), whereas the lowest for tetraploid perennial ryegrass at 30% shade (58.8%). Annual ryegrass was the fastest emerging species, whereas meadow fescue the slowest. In the growth chamber study, in comparison with perennial ryegrass, the following results may be summarized: 1) meadow fescue and tetraploid ryegrass showed coarser leaf texture, similar growth rates and Normalized Difference Vegetation Index (NDVI) value; 2) annual ryegrass had similar leaf texture, accelerated growth characteristics, and lower NDVI value; and 3) spreading perennial ryegrass displayed finer leaf texture, lower vertical growth, and similar NDVI value.

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