Predicting Behavior of Phyllosphere Bacteria in the Growth Chamber from Field Studies

2007 ◽  
pp. 277-284 ◽  
Author(s):  
Christen D. Upper ◽  
Susan S. Hirano
Keyword(s):  
Field Studies ◽  
Growth Chamber ◽  
Predicting Behavior ◽  
Phyllosphere Bacteria

Interactions of Four Herbicides with Rhizoctonia solani on Seedling Cotton

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 453-456 ◽  
Author(s):  
James M. Chandler ◽  
P. W. Santelmann
Keyword(s):  
Gossypium Hirsutum ◽  
Rhizoctonia Solani ◽  
Field Studies ◽  
Antagonistic Effect ◽  
Field Conditions ◽  
Growth Chamber ◽  
Seedling Disease ◽  
Low Level ◽  
High Level

Growth chamber and field studies were conducted to investigate the possibility of an interaction between the herbicides 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin), a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), 3- (m-tri-fluromethylphenyl)-1,1-dimethylurea (fluometuron), and 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne), and the seedling disease organism Rhizoctonia solani Kuehn in cotton (Gossypium hirsutum L.). When high levels of trifluralin or prometryne were used in the growth chamber, an interaction with the pathogen that was injurious to the cotton occurred. Prometryne and fluometuron produced an antagonistic effect on R. solani.Under field conditions, R. solani usually caused cotton injury. Interactions injurious to the cotton occurred between trifluralin and a low level of R. solani and between nitralin and a high level R. solani infestation. No interactions occurred with fluometuron or prometryne. In all instances, the effect occurred only when the herbicides were being used at high rates.

Growth, Reproductive Potential, and Control Strategies for Deeproot Sedge (Cyperus entrerianus)

2012 ◽  
Vol 26 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Charles T. Bryson ◽  
Richard Carter
Keyword(s):  
Growth Rate ◽  
Field Study ◽  
Control Strategies ◽  
Reproductive Potential ◽  
Field Studies ◽  
Growth Chamber ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
And Control ◽  
Achene Production

Greenhouse, growth chamber, and field studies were conducted at Stoneville, MS, in 2000 to 2008, to determine the growth rate, reproductive and overwintering potential, and control of deeproot sedge. In growth chamber studies, deeproot sedge growth rate (ht) and plant dry wt were greatest at 25/35 C (night/day temperatures), when compared with regimes of 5/15, 15/25, and 20/30 C. Based on the average number of scales (fruiting sites per spikelet), spikelets per inflorescence, and culms per plant, deeproot sedge reproductive potential was 2.6-, 6.2-, and 17.4-fold greater than Surinam, green, and knob sedges, respectively. A single deeproot sedge plant produced an average of 85,500 achenes annually. Mowing at 15-cm ht weekly prevented achene production but did not kill deeproot sedge plants. The average number of inflorescences produced on mowed plants was 1.2 to 4 times greater in 2- and 1-yr-old deeproot sedge plants, respectively, when compared with unmowed plants. Mature deeproot sedge achenes were produced between monthly mowings. In a 3-yr field study, glyphosate, glufosinate, hexazinone, and MSMA provided more than 85% control of deeproot sedge, and above the soil, live deeproot sedge plant dry wt was reduced by 50, 64, 68, 72, 86, and 93% by dicamba, halosulfuron-methyl, MSMA, hexazinone, glufosinate, and glyphosate, respectively. All (100%) deeproot sedge plants 1 yr old or older overwintered at Stoneville, MS, at 33°N latitude.

The effect of sulfur dioxide upon the metabolic level of adenosine triphosphate

1979 ◽  
Vol 57 (7) ◽  
pp. 759-764 ◽  
Author(s):  
Geoffrey W. Harvey ◽  
Allan H. Legge
Keyword(s):  
Sulfur Dioxide ◽  
Pinus Contorta ◽  
Ambient Air ◽  
Field Studies ◽  
Growth Chamber ◽  
Processing Plant ◽  
Atp Content ◽  
Gas Processing ◽  
Sulfur Dioxide Concentration ◽  
Sour Gas

The ATP content of lodgepole – jack pine (Pinus contorta × banksiana) hybrids in the cordillerean–boreal transition zone was monitored during sulfur dioxide fumigations. Foliage was stabilized for analysis during the course of sulfur dioxide fumigations originating from a sour gas processing plant located in west-central Alberta. Controlled sulfur dioxide fumigations of seedlings were conducted in the laboratory to measure their effect upon ATP content. Field studies demonstrated that ATP concentrations of needle cells declined as sulfur dioxide concentration increased in the ambient air. An inverse linear relationship was found between ATP content and the measured sulfur dioxide concentration. The effect could be repeated in the laboratory with growth chamber cultured seedlings only in exceptional cases. It was repeated with detached branches from the field site exposed to sulfur dioxide under laboratory conditions. The results illustrate the fundamental differences between foliage preadapted to low-level sulfur dioxide fumigations and foliage grown under optimal conditions in a growth chamber.

Absence of Internalization of Escherichia coli O157:H7 into Germinating Tissue of Field-Grown Leafy Greens

2014 ◽  
Vol 77 (2) ◽  
pp. 189-196 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
CATHY C. WEBB ◽  
JUAN CARLOS DÍAZ-PÉREZ ◽  
LINDSEY E. DAVEY ◽  
ALISON S. PAYTON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Contaminated Soil ◽  
Spinacia Oleracea ◽  
Field Studies ◽  
Growth Chamber ◽  
Escherichia Coli O157 ◽  
Apparent Lack ◽  
E Coli ◽  
Leafy Greens ◽  
Natural Isolates

Both growth chamber and field studies were conducted to investigate the potential for Escherichia coli O157:H7 to be internalized into leafy green tissue when seeds were germinated in contaminated soil. Internalized E. coli O157:H7 was detected by enrichment in both spinach (Spinacia oleracea L.) and lettuce (Lactuca sativa L.) seedlings when seeds were germinated within the growth chamber in autoclaved and nonautoclaved soil, respectively, contaminated with E. coli O157:H7 at 2.0 and 3.8 log CFU/g, respectively. Internalized E. coli O157:H7 populations could be detected by enumeration within leafy green tissues either by increasing the pathogen levels in the soil or by autoclaving the soil. Attempts to maximize the exposure of seed to E. coli O157:H7 by increasing the mobility of the microbe either through soil with a higher moisture content or through directly soaking the seeds in an E. coli O157:H7 inoculum did not increase the degree of internalization. Based on responses obtained in growth chamber studies, internalization of E. coli O157:H7 surrogates (natural isolates of Shiga toxin–negative E. coli O157:H7 or recombinant [stx- and eae-negative] outbreak strains of E. coli O157:H7) occurred to a slightly lesser degree than did internalization of the virulent outbreak strains of E. coli O157:H7. The apparent lack of internalized E. coli O157:H7 when spinach and lettuce were germinated from seed in contaminated soil (ca. 3 to 5 log CFU/g) in the field and the limited occurrence of surface contamination on the seedlings suggest that competition from indigenous soil bacteria and environmental stresses were greater in the field than in the growth chamber. On the rare occasion that soil contamination with E. coli O157:H7 exceeded 5 log CFU/g in a commercial field, this pathogen probably would not be internalized into germinating leafy greens and/or would not still be present at the time of harvest.

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.

Effectiveness of Bentazon Applied at Various Times of the Day

Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 567-570 ◽  
Author(s):  
David L. Doran ◽  
Robert N. Andersen
Keyword(s):  
Glycine Max ◽  
Practical Importance ◽  
Field Studies ◽  
Early Morning ◽  
Time Of Day ◽  
Abutilon Theophrasti ◽  
Growth Chamber ◽  
Poor Control ◽  
Late Evening

Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2, 2-dioxide] was applied postemergence to common cocklebur (Xanthium pensylvanicumWallr.) and velvetleaf (Abutilon theophrastiMedic.) at various times of the day in growth chamber and field studies and to soybeans [Glycine max(L.) Merr.] in field studies. Soybeans were tolerant of bentazon regardless of time of day when treated. Results with common cocklebur and velvetleaf suggest that the time of day when bentazon is applied can be of practical importance. Poor control might occur following application in late evening, night, or early morning.

scholarly journals ASSESSMENT OF AGRISPON, A MICROBIAL SOIL SUPPLEMENT, ON CEREAL PRODUCTION

1984 ◽  
Vol 64 (3) ◽  
pp. 607-615 ◽  
Author(s):  
D. W. McANDREW ◽  
D. J. E. DEMARS ◽  
V. O. BIEDERBECK ◽  
C. A. CAMPBELL
Keyword(s):  
Grain Yield ◽  
Protein Content ◽  
Spring Wheat ◽  
Field Studies ◽  
Triticum Aestivum L ◽  
Growth Chamber ◽  
Microbial Composition ◽  
Available Nitrogen ◽  
Hard Red Spring Wheat ◽  
Wheat Field

Agrispon has been promoted in Western Canada as a soil supplement that provides plant-available nitrogen via undefined catalytic as well as microbial processes. Testing was undertaken in a controlled environment and under field conditions, to substantiate claims made by manufacturers and promoters that this product enhances germination and availability of nitrogen to plants. Characterization of the microbial composition of this product was also undertaken. Germination of Neepawa hard red spring wheat (Triticum aestivum L.) was not influenced in a greenhouse study. Growth chamber studies did not show any beneficial effect of Agrispon on total dry matter, grain yield or protein content of Neepawa wheat. Field studies with Canuck hard red spring wheat gave similar results to those obtained in the growth chamber i. e., no benefit in grain yield or protein content of Agrispon-treated plants. Analysis of soil samples taken at the end of the experiment also revealed no treatment effect of Agrispon or N fertilizer on available NO−3-N or NH4+-N levels. Microbiological determinations revealed relatively low populations of common soil organisms.Key words: Agrispon, Nitro/Max, soil supplement, bacterial population, fertilizer

scholarly journals First Report of Musk Thistle Rust (Puccinia carduorum) in Oklahoma

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 832-832 ◽  
Author(s):  
L. J. Littlefield ◽  
W. L. Bruckart ◽  
D. G. Luster ◽  
P. W. Pratt ◽  
V. L. Scogin
Keyword(s):  
Biological Control ◽  
Rust Fungus ◽  
Field Research ◽  
Field Studies ◽  
The United States ◽  
Growth Chamber ◽  
Peat Moss ◽  
Its2 Region ◽  
Initial Field ◽  
Dna 2

Musk thistle, Carduus thoermeri (Carduus nutans subsp. leiophyllus), is an important, introduced pasture weed in central and northeastern Oklahoma. Puccinia carduorum was introduced into the United States from Turkey as a potential biological control for musk thistle. P. carduorum has not been reported previously in Oklahoma, thus precluding its field release for biological control research without APHIS approval. There is evidence the organism has moved westward since the initial field studies that began in 1987 in Virginia. In 1994 it was found in Missouri (1). In early November 1997, in Rogers County, Oklahoma, scattered populations of C. thoermeri were found that had moderate to heavy levels of infection with a rust fungus. The pustules contained mostly teliospores; based on teliospore and urediniospore morphology, the fungus was identified as P. carduorum. The morphology and dimensions of urediniospores (21 × 21 μm, avg.) and teliospores (35 × 21 μm, avg.), and the restriction of echinulations to the upper two-thirds to three-fourths of urediniospores, were consistent with P. carduorum. Infection studies with field inoculum were conducted at both Oklahoma State University and USDA-FDWSRU. Rust-infected leaves collected in Oklahoma were air dried and maintained at room temperature for 2 months prior to use as inoculum. Small, symptomless, first-year rosettes of musk thistle were transplanted from the field into a mixture of soil, sand, and peat moss in pots and placed into a growth chamber maintained at 20°C. Seeds of C. thoermeri planted into pots containing the same mixture were maintained in the same chambers. After approximately 6 to 8 weeks, when seedlings and transplants were growing vigorously, both groups of plants were dusted with urediniospores and teliospores from the dried leaves. Inoculated plants were placed either into a 20°C dew chamber for 24 h or were atomized with distilled water, placed into sealed, transparent, polyethylene bags and returned to the 20°C growth chamber for 24 h, after which time the bags were removed. Both sets of plants were then maintained at 20 to 25°C. Chlorotic flecks developed on inoculated leaves after 7 to 8 days; uredinia and urediniospores were present within 10 days after inoculation. Urediniospores from those leaves had the same dimensions and ornamentation pattern as those originally obtained from field collections. A DNA sequence analysis was conducted on the rRNA ITS2 region, which was polymerase chain reaction-amplified from genomic DNA (2) extracted from urediniospores of the Oklahoma isolate grown at FDWSRU. The sequence of the ITS2 region from those urediniospores was identical to the sequence (GenBank accession no. U57351) obtained from the isolate 7803 of P. carduorum from Turkey, used in the Virginia field studies. The confirmed presence of P. carduorum in Oklahoma will enable field research with this rust for management of musk thistle in the state. References: (1) A. B. A. M. Baudoin and W. L. Bruckart. Plant Dis. 80:1193, 1996. (2) Y. T. Berthier et al. Appl. Environ. Microbiol. 62:3037, 1996.

scholarly journals Anaerobic Soil Disinfestation Reduces Germination and Affects Colonization of Sclerotium rolfsii Sclerotia

2018 ◽  
Vol 108 (3) ◽  
pp. 342-351 ◽  
Author(s):  
Utsala Shrestha ◽  
Mary E. Dee ◽  
Bonnie H. Ownley ◽  
David M. Butler
Keyword(s):  
Field Study ◽  
C:N Ratio ◽  
Sclerotium Rolfsii ◽  
Field Studies ◽  
Growth Chamber ◽  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Soil Disinfestation ◽  
Anaerobic Soil Disinfestation ◽  
Sclerotial Germination

Growth chamber and field studies were conducted with organic amendment mixtures of carbon (C) and nitrogen (N) at C:N ratios 10:1, 20:1, 30:1, and 40:1 and amendment rates of C at 2, 4, 6, and 8 mg/g of soil (C:N ratio 30:1) to evaluate anaerobic soil disinfestation (ASD) effects on germination and colonization of Sclerotium rolfsii. In the growth chamber, sclerotial germination was reduced in all ASD treatments regardless of C:N ratio (0.6 to 8.5% germination) or amendment rate (7.5 to 46%) as compared with nonamended controls (21 to 36% and 61 to 96%, respectively). ASD treatment increased Trichoderma spp. colonization of sclerotia, with consistently higher colonization in ASD treatments with amendment rates of C at 2 or 4 mg/g of soil (>87% colonization) compared with nonamended controls (<50% colonization). In the 2014 field study, sclerotial germination was reduced by 24 to 30% in ASD treatments when compared with the nonamended control. Sclerotial colonization by Trichoderma spp. was predominant; however, other potential mycoparasites (i.e., Aspergillus spp., Fusarium spp., zygomycetes, and other fungi) were present in the field study. Amendment C:N ratios in the range of 10:1 to 40:1 were equally effective in reducing sclerotial germination and enhancing colonization by potentially beneficial mycoparasites of sclerotia.

Influence of Emulsifiable Oils and Emulsifier on the Performance of Phenmedipham, Metoxuron, Sethoxydim, and Quizalofop

1997 ◽  
Vol 11 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Hans De Ruiter ◽  
Andre J. M. Uffing ◽  
Esther Meinen
Keyword(s):  
Winter Wheat ◽  
Ethyl Ester ◽  
Rapeseed Oil ◽  
Field Studies ◽  
Mineral Oil ◽  
Growth Chamber ◽  
Common Lambsquarters ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Quizalofop Ethyl

Field and growth chamber experiments were conducted to investigate the influence of emulsifiable mineral oil, emulsifiable rapeseed oil, and the emulsifier (polyoxyethylene C13/C15oxo alcohol) on the efficacy of phenmedipham and metoxuron against common lambsquarters, and of sethoxydim and the ethyl ester of quizalofop against winter wheat. In field studies, mineral oil and rapeseed oil were equally effective in increasing the efficacy of phenmedipham (0.24 and 0.48 kg ai/ha), metoxuron (0.6 and 1.2 kg ai/ha), and sethoxydim (0.05 and 0.1 kg ai/ha), but mineral oil was superior to rapeseed oil with quizalofop. In growth chamber studies, mineral oil and rapeseed oil were equally effective in increasing the efficacy of metoxuron, sethoxydim, and quizalofop-ethyl, but rapeseed oil was more effective than mineral oil with phenmedipham. Both in the field and in the growth chamber, the emulsifier was at least as effective as the oil adjuvants, when combined with all herbicides except sethoxydim. The herbicide doses giving 50% response (ED50) were determined for the growth chamber experiments. The adjuvants reduced the ED502.7-fold with phenmedipham, 51-fold with metoxuron, 2.7-fold with sethoxydim, and 6.8-fold with quizalofop when averaged over the three adjuvants. It was concluded that rapeseed oil (all tested herbicides except quizalofop) or the emulsifier (all tested herbicides except sethoxydim) can serve as a substitute for mineral oil.

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