Ethylene: A Witchweed Seed Germination Stimulant

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 433-436 ◽  
Author(s):  
Robert E. Eplee
Keyword(s):  
United States ◽  
Seed Germination ◽  
Clay Soil ◽  
Soil Surface ◽  
Field Studies ◽  
The United States ◽  
Major Contributor ◽  
Single Treatment ◽  
Striga Asiatica ◽  
Heavy Clay

Ethylene gas (C2H4) was found to stimulate the germination of witchweed [Striga asiatica(L.) O. Kuntze] seeds. Ethylene diffuses greater than 120 cm horizontally from point of injection and more than 90 cm below the soil surface. Rates of 0.42 kg/ha induced germination of witchweed seeds in sandy soil; but 1.1 kg/ha is required on a heavy clay soil. Witchweed seeds respond to ethylene after a period of preconditioning that is necessary to break dormancy. Under field conditions in the Carolinas, maximum response of seeds to ethylene occurs between late April and late July. Field studies indicate a 90% reduction in viable witchweed seeds occurs where a single treatment with ethylene has been applied. The use of ethylene appears now to be a major contributor toward the eventual eradication of witchweed from the United States.

scholarly journals The effect of grass on trees

1925 ◽  
Vol 97 (683) ◽  
pp. 284-321 ◽  
Keyword(s):  
United States ◽  
Great Britain ◽  
Clay Soil ◽  
Fruit Trees ◽  
The United States ◽  
Temperate Zone ◽  
Present Condition ◽  
Free Competition ◽  
Heavy Clay ◽  
The Tropics

In the meadows and pastures of the temperate regions and the tropics, trees flourish when surrounded by communities of grasses and herbs. Such grassland is, with few exceptions, an artificial product, created by man from areas originally forest, and maintained in its present condition by such agencies as grazing, cropping, mowing and manuring. If left to themselves most of the meadows and pastures on the earth’s surface would soon revert to the original forest, the rate depending on a number of circumstances, including the nature of the weapons possessed by the trees in suppressing the grasses and herbs. In the tropics, where pastures are much fewer than in the temperate zone, grassland after enclosure becomes covered by shrubs and trees with remarkable rapidity. Although trees soon oust grasses from the habitat under conditions of free competition, nevertheless cases occur in which grass is able to suppress certain species of trees. One such example has recently been investigated in great detail in Great Britain by the Duke of Bedford and the late Mr. S. U. Pickering. At the Woburn Experiment Station fruit trees such as apples, pears, plums and cherries failed to flourish under grass on a heavy clay soil. Similar results have been obtained in the United States and also on the Gangetic alluvium at Pusa.

scholarly journals First Report of Sclerotinia sclerotiorum on Campanula carpatica and Schizanthus × wisetonensis in Italy

Plant Disease ◽  
2002 ◽  
Vol 86 (1) ◽  
pp. 71-71
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Ornamental Plants ◽  
Soil Surface ◽  
The United States ◽  
First Report ◽  
Potted Plants ◽  
Initial Symptoms ◽  
Stem Necrosis ◽  
Campanula Carpatica

The production of potted ornamental plants is very important in the Albenga Region of northern Italy, where plants are grown for export to central and northern Europe. During fall 2000 and spring 2001, sudden wilt of tussock bellflower (Campanula carpatica Jacq.) and butterfly flower (Schizanthus × wisetonensis Hort.) was observed on potted plants in a commercial greenhouse. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of the lower leaves. As stem necrosis progressed, infected plants growing in a peat, bark compost, and clay mixture (70-20-10) wilted and died. Necrotic tissues were covered with whitish mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem pieces of both plants disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with streptomycin sulphate at 100 ppm. Pathogenicity of three isolates obtained from each crop was confirmed by inoculating 45- to 60-day-old C. carpatica and Schizanthus × wisetonensis plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelia and sclerotia of each isolate was placed on the soil surface around the base of previously artificially wounded or nonwounded plants. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of stem blight of C. carpatica and Schizanthus × wisetonensis caused by S. sclerotiorum in Italy. The disease was previously observed on C. carpatica in Great Britain (2) and on Schizanthus sp. in the United States (1). References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) J. Rees. Welsh J. Agric. 1:188, 1925.

scholarly journals Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against fleas in cats, under field conditions

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 22 ◽  
Author(s):  
Eric Tielemans ◽  
Tomoko Otsuki ◽  
Tara Cheesman ◽  
Fiona Selmes ◽  
Anthony Pfefferkorn ◽  
...  
Keyword(s):  
United States ◽  
Field Studies ◽  
The United States ◽  
Positive Control ◽  
Control Group ◽  
The Novel ◽  
Domestic Cats ◽  
Label Dose ◽  
Treatment Tolerance ◽  
Significant Health

Esafoxolaner is a purified afoxolaner enantiomer with insecticidal and acaricidal properties. It is combined with eprinomectin and praziquantel, nematodicidal and cestodicidal compounds, in a novel topical endectoparasiticide formulation for cats. This novel formulation was tested in four field studies, in the United States, Europe, Japan and Australia. In all studies, naturally flea-infested domestic cats were treated with the novel formulation at the label dose and conditions of use. The main objective, identical in the four studies, was to assess efficacy on fleas, based on comparison of mean number of fleas found on infested cats before and one month after treatment. Tolerance to the product was also evaluated in the four studies. Otherwise, the studies had some differences in their design and secondary objectives, for example testing for a reduction in flea infestation-related cutaneous signs, testing of one treatment or of three monthly treatments, and use of a positive control group. In the four studies, a total of 307 cats were treated with the novel formulation. The reduction of fleas one month after treatment was 97.7%, 98.8%, 100% and 99.7% in the United States, Europe, Japan and Australia, respectively. There were no significant health abnormalities attributed to treatment in any of the studies.

The Diffusion of New Hospital Technologies in the United States

1976 ◽  
Vol 6 (4) ◽  
pp. 557-580 ◽  
Author(s):  
Louise B. Russell
Keyword(s):  
United States ◽  
Intensive Care ◽  
Hospital Care ◽  
Hospital Costs ◽  
The United States ◽  
Major Contributor ◽  
Certificate Of Need ◽  
Hospital Regulation ◽  
Resource Requirements ◽  
Competing Technologies

Increases in the real resources used in hospital care have been an important cause behind rising hospital costs in the United States. Many of these resources have taken the form of new hospital technologies, and this paper begins by reviewing the trends in adoption of new hospital technologies over the years 1950–1974. The resource requirements, costs, and to the extent possible the patient benefits, of two of these technologies are then discussed in more detail: intensive care, a widespread facility with many variations, has been a major contributor to hospital costs; radiotherapy has been characterized by a succession of competing technologies. Regulatory efforts such as certificate-of-need reviews would be more effective if they viewed hospitals as flexible collections of such technologies—with the costs and patient benefits of each to be weighed separately—rather than primarily in terms of numbers of beds. A national center to collect information on the separate technological functions of hospitals and make it available to interested groups would make a useful contribution to hospital regulation.

scholarly journals The Impact of Bt Corn on Aflatoxin-Related Insurance Claims in the United States

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jina Yu ◽  
David A. Hennessy ◽  
Felicia Wu
Keyword(s):  
United States ◽  
Inverse Correlation ◽  
Field Studies ◽  
The United States ◽  
Economic Benefits ◽  
Aflatoxin Contamination ◽  
Economic Losses ◽  
Bt Corn ◽  
Insurance Claims ◽  
The Impact

Abstract Previous field studies have reached no collective consensus on whether Bt corn, one of the most commonly planted transgenic crops worldwide, has significantly lower aflatoxin levels than non-Bt isolines. Aflatoxin, a mycotoxin contaminating corn and other commodities, causes liver cancer in humans and can pose severe economic losses to farmers. We found that from 2001–2016, a significant inverse correlation existed between Bt corn planting and aflatoxin-related insurance claims in the United States, when controlling for temperature and drought. Estimated benefits of aflatoxin reduction resulting from Bt corn planting are about $120 million to $167 million per year over 16 states on average. These results suggest that Bt corn use is an important strategy in reducing aflatoxin risk, with corresponding economic benefits. If the same principles hold true in other world regions, then Bt corn hybrids adapted to diverse agronomic regions may have a role in reducing aflatoxin in areas prone to high aflatoxin contamination, and where corn is a dietary staple.

A revision of species of the genus Haematoloechus Looss, 1899 (Trematoda: Haematoloechidae) from Canada and the United States

1981 ◽  
Vol 59 (9) ◽  
pp. 1836-1846 ◽  
Author(s):  
Murray J. Kennedy
Keyword(s):  
United States ◽  
Host Range ◽  
Geographical Variation ◽  
Rana Catesbeiana ◽  
Field Studies ◽  
The United States ◽  
Valid Species ◽  
Narrow Host Range ◽  
Species Groups ◽  
Degree Of Maturity

Previous experimental and field studies have shown that variations within the genus Haematoloechus may result from differences in age and degree of maturity, extent of crowding, species of host, and other factors.Based on these observations, only 6 of the 15 previously known species from Canada and the United States are considered valid. The valid species and their synonyms are as follows: Haematoloechus longiplexus Stafford, 1902; H. breviplexus Stafford, 1902; H. varioplexus Stafford, 1902 (= H. parviplexus, = H. buttensis, = H. similiplexus, = H. floedae, and H. uniplexus); H. kernensis Ingles, 1932 (= H. tumidus); H. medioplexus Stafford, 1902; and H. complexus (Seely, 1906) (= H. coloradensis, = H. confusus, = H. oxyorchis).The existence of three species groups is hypothesized. Haematoloechus longiplexus and H. breviplexus constitute one group, characterized by little geographical variation and a narrow host range. They are typically parasites of Rana catesbeiana and R. clamitans. Haematoloechus varioplexus and H. kernensis constitute the second group. These species have a wider host range and greater variation in characters purported to be specific differences. The third group includes those lung flukes which do not contain extracaecal loops (H. medioplexus and H. complexus). Of these, only H. medioplexus had little geographical variation and was found to occur in a single frog host.

scholarly journals Differences in seed properties and germination between native and introduced populations of Triadica sebifera

2019 ◽  
Vol 13 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Jialiang Zhang ◽  
Evan Siemann ◽  
Baoliang Tian ◽  
Wei Huang ◽  
Jianqing Ding
Keyword(s):  
United States ◽  
Seed Germination ◽  
Soluble Protein ◽  
Native Species ◽  
Seed Mass ◽  
The United States ◽  
Invasion Success ◽  
Native Range ◽  
Triadica Sebifera ◽  
Introduced Range

Abstract Aims Seeds of many invasive plants germinate more quickly than those of native species, likely facilitating invasion success. Assessing the germination traits and seed properties simultaneously for introduced and native populations of an invasive plant is essential to understanding biological invasions. Here, we used Triadica sebifera as a study organism to examine intraspecific differences in seed germination together with seed characteristics. Methods We measured physical (volume, mass, coat hardness and coat thickness of seeds) and chemical (crude fat, soluble protein, sugar, gibberellins [GA] and abscisic acid [ABA] of kernels) properties of T. sebifera seeds collected in 2017 from 12 introduced (United States) populations and 12 native (China) populations and tested their germination rates and timing in a greenhouse experiment in China. Furthermore, we conducted an extra experiment in the United States using seeds collected in 2016 and 2017 to compare the effects of study sites (China vs. United States) and seed collection time (2016 vs. 2017) on seed germination. Important Findings Seeds from the introduced range germinated faster than those from the native range. Physical and chemical measurements showed that seeds from the introduced range were larger, had higher GA concentrations and GA:ABA ratio, but lower crude fat concentrations compared to those from the native range. There were no significant differences in seed mass, coat hardness and coat thickness or kernel ABA, soluble protein or sugar concentrations between seeds from introduced vs. native ranges. Germination rates were correlated between United States and China greenhouses but germination rates for populations varied between collection years. Our results suggest that larger seeds and higher GA likely contribute to faster germination, potentially facilitating T. sebifera invasion in the introduced range.

scholarly journals First Report of Stem and Crown Rot of Garbanzo Caused by Sclerotinia minor in the United States and by Sclerotinia sclerotiorum in Arizona

Plant Disease ◽  
2000 ◽  
Vol 84 (11) ◽  
pp. 1250-1250 ◽  
Author(s):  
M. E. Matheron ◽  
M. Porchas
Keyword(s):  
United States ◽  
Cicer Arietinum ◽  
Soil Surface ◽  
The United States ◽  
Crown Rot ◽  
Sclerotinia Minor ◽  
First Report ◽  
Initial Symptoms ◽  
Stem Necrosis ◽  
White Mycelium

In March 2000, plants began to die within two garbanzo (Cicer arietinum L.) fields about 48 km apart in southwestern Arizona. Initial symptoms included wilting of leaves and stem necrosis on individual branches, followed by entire plant necrosis and death. White mycelium was present on plant stems near the soil surface. In one field, small black irregularly shaped sclerotia (1 mm in diameter) were present on the infected stem surface along with the white mycelia, whereas in the other field the associated sclerotia were of similar shape but larger (5 to 6 mm in diameter). Isolation from diseased garbanzo stem tissue from the respective fields yielded Sclerotinia minor, which produced small sclerotia when cultured on potato-dextrose agar and S. sclerotiorum, which produced the typical larger sclerotia of this species. To fulfill Koch's postulates, healthy plants and associated soil from a garbanzo field with no evidence of infection by Sclerotinia were removed with a shovel and transferred into a series of 8-liter plastic pots. After transporting back to the laboratory, some of the plants were inoculated by wounding stems with a 5-mm-diameter cork borer, placing an agar disk containing either S. minor or S. sclerotiorum onto each wound, securing the agar disk to the stem with plastic tape, then incubating the plants at 25°C for 7 days. Control plants were treated similarly except that agar disks did not contain Sclerotinia. Stems inoculated with S. minor or S. sclerotiorum developed symptoms of wilt and necrosis, including the appearance of white mycelium and sclerotia on the stem surface, whereas control plants remained healthy. S. minor or S. sclerotiorum were recovered from garbanzo stems inoculated with the respective species of the pathogen. Sclerotinia leaf drop, which can be caused by S. minor or S. sclerotiorum on lettuce in Arizona, had been observed in both fields previously. Garbanzo fields in Arizona usually are watered by furrow irrigation. Disease was most severe in areas of the garbanzo fields that were heavily irrigated with resultant wetting of tops of plant beds. Proper management of irrigation water and avoidance of establishing a garbanzo planting in fields following lettuce could help reduce future losses from these pathogens. S. minor previously had been reported as a pathogen on Cicer arietinum from the island of Sardinia (2); however, this is apparently the first report of the pathogen on garbanzo other than in Sardinia. S. sclerotiorum has been reported as a pathogen on this host in several countries including the United States (California) (1) but not previously in the state of Arizona. References: (1) I. W. Buddenhagen, F. Workneh, and N. A. Bosque-Perez. Int. Chickpea Newsl. 19:9–10, 1988. (2) F. Marras. Rev. Appl. Mycol. 43:112, 1964.

scholarly journals A BAIXA INCIDÊNCIA DE PESQUISA EMPÍRICA E A CULTURA MANUALESCA COMO OBSTÁCULOS PARA O DESENVOLVIMENTO DO DIREITO

2017 ◽  
Vol 8 (2) ◽  
pp. 247
Author(s):  
José Maria de Morais Borges Neto ◽  
José Eduardo Barroso Colácio ◽  
Fayga Silveira Bedê
Keyword(s):  
United States ◽  
Empirical Research ◽  
Field Research ◽  
Field Studies ◽  
The United States ◽  
Research Development ◽  
Legal Research ◽  
De Se ◽  
Main Factors

O presente estudo busca compreender as razões pelas quais a pesquisa jurídica no Brasil permanece relativamente infensa à pesquisa empírica. Percebe-se que, em outras matrizes jurídicas, como é o caso dos Estados Unidos, a adoção dos estudos de campo já se encontra muito mais incorporada em seu repertório, tendo em vista o papel central da jurisprudência e o modo como ela reverbera na Academia, em termos de análise do discurso produzido pelas suas cortes. No caso do Brasil, muito embora se reconheça uma série de iniciativas relevantes no sentido de promover a adoção da pesquisa empírica no Direito, de modo geral, ainda se tratam de práticas isoladas, fruto dos esforços envidados por grupos de excelência. Compreende-se que a dificuldade de se imiscuir novas práticas de pesquisa de campo no bojo da pesquisa jurídica brasileira tem causas multifatoriais. Para os limites do presente estudo, reflete-se sobre a hipótese de a cultura manualesca – cujo maior esteio reside em meros argumentos de autoridade – constituir um dos principais fatores de inibição à pesquisa empírica. De acordo com essa hipótese, a ser testada em trabalhos posteriores, a tendência dogmatizante dos manuais tornaria a pesquisa jurídica mais autorreferente e menos permeável aos estudos de campo.Palavras-chave: Pesquisa empírica. Desenvolvimento do Direito. Cultura de Manual. Abstract:The present study seeks to understand the reasons why legal research in Brazil remains relatively unfriendly toward empirical research. In other legal domains, such as the case in the United States, the resource of field studies is already much more incorporated into its repertoire, given the central role of jurisprudence and the way it reverberates in the Academy, in terms of analysis of the discourse produced by their courts. In the case of Brazil, although a series of relevant initiatives are recognized to promote the adoption of empirical research in the Law, in general, they are still isolated practices, the result of the efforts made by groups of excellence. It is understood that the difficulty to introduce new field research practices within the scope of Brazilian legal research has many causes. For the limits of the present study, it is reflected on the hypothesis that the textbook culture, whose main foundation are mere arguments of authority, constitutes one of the main factors of inhibition to the empirical research. According to this hypothesis, to be tested in later works, the dogmatic tendency of textbooks would make legal research more self-referential and less permeable to field studies. Keywords: Empirical research. Development of Law. Textbook Culture

scholarly journals Occurrence of Blight Caused by Sclerotium rolfsii on Lolium perenne in Argentina

Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 910-910
Author(s):  
L. Goldring ◽  
M. Lacasa ◽  
E. R. Wright ◽  
B. A. Pérez ◽  
M. C. Rivera
Keyword(s):  
United States ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tap Water ◽  
Sclerotium Rolfsii ◽  
Soil Surface ◽  
Pathogenic Fungi ◽  
The United States ◽  
Buenos Aires Province ◽  
Pathogenicity Test

A perennial ryegrass (Lolium perenne L.) lawn located at Castelar (Buenos Aires Province) showed disease symptoms during the summer of 2003. Chlorotic patches as much as 15 cm in diameter appeared on the lawn. Later, dead plants with white mycelia developing on the crown and surrounding soil occurred at the periphery of the rings. Plants showed leaf chlorosis and crown and root rot. No sclerotia developed on plant organs. Diseased plants were collected, washed with running tap water for 4 h, and disinfested in 5% NaOCl for 2 min. Pieces, 3 to 5 mm long from symptomatic leaves, crowns, and roots, were incubated on 2% potato dextrose agar (PDA) at 22 to 25°C with a 12-h light/dark cycle. Mycelia growing on the soil surface was transferred to PDA and incubated under the same conditions. After 3 to 4 days, white, conspicuous mycelia that produced sclerotia grew from diseased tissue pieces and soil mycelial samples. Sclerotia were nearly spherical, 1 to 2 mm in diameter, white but turning brown with age, and produced in large numbers over the entire colony surface. Primary hyphae showed clamp connections at the septa. A pathogenicity test was performed with 20 1-month-old plants of L. perenne grown in a 1:1 (v/v) mixture of sand and soil contained in 24- × 17- × 4-cm plastic trays. Seven-day-old fungal cultures grown on PDA were cut into 1- cm2 pieces and placed among the plants on the substrate. Each tray was inoculated with seven inoculum pieces. Five trays of plants were inoculated with the fungus, and plants in five trays that served as controls had only sterile pieces of PDA placed on the substrate. All plants were maintained at 25°C and watered frequently. First symptoms, consisting of chlorosis, were observed 4 days after inoculation. Of the plants, 34, 59, 60, 65, and 70% developed symptoms 6, 9, 14, 17, and 21 days after inoculation, respectively. Control plants remained healthy. The fungus was reisolated from diseased plants and identified as Sclerotium rolfsii Sacc. (teleomorph Athelia rolfsii (Curzi) C.C. Tu & Kimbr.) on the basis of morphological and cultural characteristics (3,4). The disease has been observed causing stalk rot on perennial ryegrass in the United States (1) and Australia (2). To our knowledge, this is the first report of S. rolfsii causing disease on L. perenne in Argentina. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society. St. Paul, MN. 1989. (2) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (3) J. E. M. Mordue. No. 410 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, UK, 1974. (4) Z. K. Punja and A. Damiani. Mycologia 88:694, 1996.

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