Responses of ‘Kentucky-31’ Tall Fescue to Varying Forcipata loca DeLong & Caldwell Infestation Levels: Growth Chamber Study (Homoptera: Cicadellidae, Typhlocybinae) 1

1981 ◽  
Vol 10 (4) ◽  
pp. 550-553
Author(s):  
S. Quisenberry ◽  
T. R. Yonke
Keyword(s):  
Tall Fescue ◽  
Growth Chamber ◽  
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 Biological Control of Bipolaris sorokiniana on Tall Fescue by Stenotrophomonas maltophilia Strain C3

1999 ◽  
Vol 89 (9) ◽  
pp. 817-822 ◽  
Author(s):  
Z. Zhang ◽  
G. Y. Yuen
Keyword(s):  
Tall Fescue ◽  
Leaf Spot ◽  
Stenotrophomonas Maltophilia ◽  
Field Experiments ◽  
Bipolaris Sorokiniana ◽  
Colloidal Chitin ◽  
Growth Chamber ◽  
Complete Suppression ◽  
Infection Frequency ◽  
Leaf Surfaces

Stenotrophomonas maltophilia strain C3 was evaluated for control of leaf spot on tall fescue (Festuca arundinacea) caused by Bipolaris sorokiniana. In growth chamber experiments, C3 inhibited conidial germination on leaf surfaces and reduced lesion frequency and percent diseased leaf area compared with nontreated controls. The amount of leaf spot suppression was related to the C3 dose applied. The highest dose tested, 109 CFU/ml, prevented nearly all B. sorokiniana conidia from germinating on treated leaf surfaces and provided nearly complete suppression of lesion development. When colloidal chitin was added to C3 cell suspensions of 107 or 108 CFU/ml, biocontrol efficacy was significantly increased over C3 applied alone, whereas addition of chitin to a C3 cell suspension of 109 CFU/ml had no effect. In field experiments, application of C3 to tall fescue turf resulted in significant reductions in infection frequency and disease severity compared with nontreated controls. Strain C3 applied at 109 CFU/ml was more effective than C3 applied at 107 CFU/ml, and amendment of the lower dose with colloidal chitin enhanced its efficacy. Populations sizes of C3 established on foliage in a growth chamber and in the field were directly related to dose applied. Chitin amendments did not affect C3 population size.

Relative Tolerance of Perennial Ryegrass (Lolium perenne) and Tall Fescue (Festuca arundinacea) to Flucarbazone

2012 ◽  
Vol 26 (4) ◽  
pp. 673-678 ◽  
Author(s):  
Patrick E. McCullough ◽  
Jialin Yu ◽  
James T. Brosnan ◽  
Gregory K. Breeden
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Field Experiments ◽  
Early Summer ◽  
Growth Chamber ◽  
Shoot Biomass ◽  
Relative Tolerance ◽  
Sequential Treatments

Flucarbazone controls certain grassy weeds in wheat and may have potential for controlling perennial ryegrass in tall fescue turf. The objective of these experiments was to investigate perennial ryegrass and tall fescue tolerance to flucarbazone at two application timings. In field experiments, flucarbazone applications in May were more injurious to both species than in February and March. Single applications of flucarbazone from 30 to 60 g ai ha−1in May injured both species 35 to 50% and sequential treatments increased injury approximately twofold. Two applications of flucarbazone at 60 g ha−1in May injured both grasses > 90%, similar to sequential applications of trifloxysulfuron at 29 g ai ha−1. In growth chamber experiments, injury from flucarbazone on both grasses increased as temperature increased from 10 to 30 C. Flucarbazone reduced total shoot biomass of both grasses at all temperatures after 4 wk. Overall, perennial ryegrass and tall fescue are tolerant to flucarbazone at moderate temperatures (10 to 20 C). However, injury increased substantially under warmer conditions (30 C), suggesting flucarbazone could control perennial ryegrass and tall fescue during late spring and early summer.

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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