EXPERIMENTS ON CHEMICAL CONTROL OF DAMPING-OFF IN PINUS RESINOSA AIT.

1942 ◽  
Vol 20c (12) ◽  
pp. 559-571 ◽  
Author(s):  
L. P. V. Johnson ◽  
G. M. Linton

Results from a series of greenhouse and nursery experiments on the relative control of damping-off in red pine, afforded by a wide range of chemicals, brought out the following points: (1) Semesan solutions in concentrations of 1:100 to 1:150 applied as soil treatment gave consistently the best control in both greenhouse and nursery. (2) Red copper oxide suspension in concentrations of 1:250 to 1:500 applied as a soil treatment was also effective, particularly in the greenhouse. (3) Red copper oxide and zinc oxide dusts used as seed treatments gave effective control under greenhouse conditions. (4) In the greenhouse, combinations of seed and soil treatments failed to prove more effective than treatments applied separately, while under certain nursery conditions the combined treatments were significantly less effective. (5) Fungicides as a group generally proved more effective than acidifying agents such as sulphuric acid and aluminium sulphate. It appeared that the acidifying agents gave good control in seasons of normal rainfall, but were more or less ineffective in dry seasons, when relatively large quantities of slightly alkaline irrigation water were applied, or in wet seasons, when excessive percolation occurred. (6) Seedlings from two-year–old red pine seed of somewhat reduced vitality proved to be much more susceptible than those from one-year–old seed.White spruce was used in some of the preliminary experiments and proved to be much less susceptible than red pine, although very similar in response to the various treatments.

1969 ◽  
Vol 16 (3) ◽  
pp. 285-324
Author(s):  
J. A. B. Nolla

1. Damping-off of tobacco is a very severe disease in Pu erto Rico. 2. The disease is caused by Pythium debaryanum and Phytophthora Parasitica var. nicotianae. 3. The agents of transportation of the fungus are water currents, laborers, animals, burrowing insects, etc. 4. Leaves are infected by zoospores of Phy. Parasitica var. nicotianae but apparently not by those of P. debaryanum. 5. Environmental conditions are important factors influencing the spread and severity of the disease. The disease seems to be equally severe during all seasons provided the proper moisture relations are maintained. Organic manures seem to influence favorably the incidence of the disease. The disease is severe on thickly-sowed beds. 6. Control of damping-dff of tobacco is today one of the most serious problems with Puerto Rico tobacco growers. 7. When the disease appears in small areas only, it may be checked by drenching these with a 1-30 formaldehyde solution. 8. Soil disinfestation by means of steam or with formaldehyde does not seem to be practicable under Puerto Rican conditions. 9. Phy. Parasitica var. nicotianae is probably slightly less susceptible to the sterilizing action of formaldehyde than P. debaryanum. 10. Mercury compounds have been found injurious to tobacco seedlings, and ineffectiYe against the clamping-off pathogenes. 11. In preliminary trials two applications of Corona Copper carbonate of four grams per square foot, before seed sowing, and at the same rate a week after germination, were fairly effective. Two applications of copper carbonate in the field did not give effective control probably due to the heavy rains and to overcrowding of the seedlings. Two late applications of copper carbonate on heavily infected beds were unsuccessful. Two 4-gram applications of copper carbonate resulted in good control of the damping-off of tomato, pepper, and eggplant. 12. Copper stereate, in two applications of 4 grams each, seemed to control P. debaryanum but did not have any effect on Phy. Parasitica var. nicotianae. 13. Bayer dust and Uspulun were injurious when applied to the foliage and proved to be ineffective in the control of the disease. 14. Copper sulfate solutions (4 and 5 pounds to 50 gallons) applied at the rate of 1/2 gallon per square foot before sowing the seed were ineffective. 15. Effectiveness of copper fluosilicate is doubtful. 16. Acetic acid does not control the disease under conditions of high infection. 17. Two applications of 4-4-50 and 5-5-50 Bordeaux mixture at the rate of 1/2 gallon per square foot, one before sowing the seed and the other a week after germination, were effective in controlling damping-off. The treatment was not very successful when applied to beds in the field in which the disease had made its appearance. 18. Injury to seedlings resulted when copper carbonate was applied to a tobacco seed-bed on the site of an old bed. It was proved by experiment that the injury was not clue to dryness. Soil reaction appears to have little to do as a direct cause of the injurious action. No injurious action of formaldehyde or acetic acid was found under similar conditions. Charcoal was not effective in preventing injury from the copper compounds. Recovery from injury resulted in one case when a sodium nitrate solution was applied. It is suggested that the injurious action is connected with nitrification which would be hindered by the lasting effect of the copper treatments. 19. Continuous cultivation of infested soils for periods of six to twelve months does not eradicate the disease.


Author(s):  
Olena Zayats ◽  

The article examines the competitive status and competitive positions of Ukraine. It proves that in the current context the competitive status of the national economy is determined by the presence of a strong global competitive force that provides dynamic growth based on innovation potential, developed institutions, infrastructure, ICT adoption, macroeconomic stability, health, skills, product market, labor market, financial system, market size, business dynamism rather than by traditional factors (natural resources, geopolitical situation). It has been identified that a wide range of factors in global competitive force establishment suggests the complexity of its assessment. It has been noted that in world economic practice the Global Competitiveness Index of the World Economic Forum is predominantly used to assess the competitive status of the national economy. It has been determined that according to this index, in the overall ranking among 141 countries in 2019, Ukraine ranked 85th (2009-2010 – 82/133; 2018 – 83/140). The article analyzes of the competitive status of Ukraine in the international arena in terms of twelve pillars of the studied index and in the context of components of the said pillars. The dynamics of Ukraine's global competitive force in recent years shows that there has not been any build up. However, if one analyzes it in terms of the criteria of the global competitive force of the domestic economy, their assessment is volatile: the main regression can be traced in the sphere of the financial system, where Ukraine dropped by 19 positions in one year (2018 – 117/140, 2019 – 136/141), and the greatest progress is observed in the product market, where Ukraine rose by 16 positions in one year (2018 – 73/140, 2019 – 57/141). Analysis of the components of Ukraine’s global competitive force criteria shows that the worst positions in terms of such components are as follows: non-performing loans (% of gross total loans) – 139/141 and soundness of banks – 131/141. The best positions are in terms of the following components: costs of starting a business – 14/141 and attitude towards entrepreneurial risk – 18/141.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 369
Author(s):  
Pasqua Veronico ◽  
Maria Teresa Melillo

Plant parasitic nematodes are annually responsible for the loss of 10%–25% of worldwide crop production, most of which is attributable to root-knot nematodes (RKNs) that infest a wide range of agricultural crops throughout the world. Current nematode control tools are not enough to ensure the effective management of these parasites, mainly due to the severe restrictions imposed on the use of chemical pesticides. Therefore, it is important to discover new potential nematicidal sources that are suitable for the development of additional safe and effective control strategies. In the last few decades, there has been an explosion of information about the use of seaweeds as plant growth stimulants and potential nematicides. Novel bioactive compounds have been isolated from marine cyanobacteria and sponges in an effort to find their application outside marine ecosystems and in the discovery of new drugs. Their potential as antihelmintics could also be exploited to find applicability against plant parasitic nematodes. The present review focuses on the activity of marine organisms on RKNs and their potential application as safe nematicidal agents.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Li Cao ◽  
Junling Wu ◽  
Qiang Zhang ◽  
Bashayer Baras ◽  
Ghalia Bhadila ◽  
...  

Orthodontic treatment is increasingly popular as people worldwide seek esthetics and better quality of life. In orthodontic treatment, complex appliances and retainers are placed in the patients’ mouths for at least one year, which often lead to biofilm plaque accumulation. This in turn increases the caries-inducing bacteria, decreases the pH of the retained plaque on an enamel surface, and causes white spot lesions (WSLs) in enamel. This article reviews the cutting-edge research on a new class of bioactive and therapeutic dental resins, cements, and adhesives that can inhibit biofilms and protect tooth structures. The novel approaches include the use of protein-repellent and anticaries polymeric dental cements containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminododecyl methacrylate (DMAHDM); multifunctional resins that can inhibit enamel demineralization; protein-repellent and self-etching adhesives to greatly reduce oral biofilm growth; and novel polymethyl methacrylate resins to suppress oral biofilms and acid production. These new materials could reduce biofilm attachment, raise local biofilm pH, and facilitate the remineralization to protect the teeth. This novel class of dental resin with dual benefits of antibacterial and protein-repellent capabilities has the potential for a wide range of dental and biomedical applications to inhibit bacterial infection and protect the tissues.


2012 ◽  
Vol 52 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Ilias Travlos

Evaluation of Herbicide-Resistance Status on Populations of Littleseed Canarygrass (Phalaris MinorRetz.) from Southern Greece and Suggestions for their Effective ControlIn 2010, a survey was conducted in the wheat fields of a typical cereal-producing region of Greece to establish the frequency and distribution of herbicide-resistant littleseed canarygrass (Phalaris minorRetz.). In total, 73 canarygrass accessions were collected and screened in a field experiment with several herbicides commonly used to control this weed. Most of the weed populations were classed as resistant (or developing resistance) to the acetyl-CoA varboxylase (ACCase)-inhibiting herbicide diclofop, while resistance to clodinafop was markedly lower. The results of the pot experiments showed that some of the canary populations were found to have a very high level of diclofop resistance (resistance index up to 12.4), while cross resistance with other herbicides was also common. The levels of resistance and cross resistance patterns among populations varied along with the different amounts and times of selection pressure. Such variation indicated either more than one mechanism of resistance or different resistance mutations in these weed populations. The population which had the highest diclofop resistance level, showed resistance to all aryloxyphenoxypropinate (APP) herbicides applied and non-ACCase inhibitors. Alternative ACCase-inhibiting herbicides, such as pinoxaden remain effective on the majority of the tested canarygrass populations, while the acetolactate synthase (ALS)-inhibiting herbicide mesosulfuron + iodosulfuron could also provide some solutions. Consequently, there is an opportunity to effectively control canarygrass by selecting from a wide range of herbicides. It is the integration of agronomic practices with herbicide application, which helps in effective management ofP. minorand particularly its resistant populations.


1988 ◽  
Vol 18 (2) ◽  
pp. 365-374 ◽  
Author(s):  
Susan Golombok ◽  
Parimala Moodley ◽  
Malcolm Lader

SynopsisIn view of the very extensive and often prolonged use of benzodiazepines in therapeutic practice, this study was designed to investigate whether or not cognitive ability is impaired in longterm benzodiazepine users, and to determine the nature and extent of any deficit. Fifty patients currently taking benzodiazepines for at least one year, thirty-four who had stopped taking benzodiazepines, and a matched control group of subjects who had never taken benzodiazepines or who had taken benzodiazepines in the past for less than one year were administered a battery of neuropsychological tests designed to measure a wide range of cognitive functions. It was found that patients taking high doses of benzodiazepines for long periods of time perform poorly on tasks involving visual-spatial ability and sustained attention. This is consistent with deficits in posterior cortical cognitive function.


2008 ◽  
Vol 1087 ◽  
Author(s):  
Marco Palumbo ◽  
Simon J. Henley ◽  
Thierry Lutz ◽  
Vlad Stolojan ◽  
David Cox ◽  
...  

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium intermedium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts represented by the following families: Begoniaceae, Bromeliaceae, Chenopodiaceae, Compositae, Coniferae, Cruciferae, Euphorbiaceae, Geraniaceae, Gramineae, Leguminosae, Liliaceae, Linaceae, Moraceae, Onagraceae, Ranunculaceae, Rosaceae, Solanaceae, Ulmaceae, Violaceae; also in the Equisetales and Filicales. DISEASES: Damping-off of seedlings, foot rot and root rot of ornamentals, occasionally of crop plants and trees. GEOGRAPHICAL DISTRIBUTION: Asia (China); Australia & Oceania (Hawaii); Europe (England, Belgium, France, Germany, Holland, Sweden, U.S.S.R.); North America (U.S.A.); South America (Argentina). TRANSMISSION: A common soil inhabitant.


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium aphanidermatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts, often similar to those attacked by P. butleri, but inducing different symptoms, represented in the following families: Amaranthaceae, Amaryllidaceae, Araceae, Basellaceae, Bromeliaceae, Cactaceae, Chenopodiaceae, Compositae, Coniferae, Convolvulaceae, Cruciferae, Cucurbitaceae, Euphorbiaceae, Gramineae, Leguminosae, Linaceae, Malvaceae, Moraceae, Passifloraceae, Rosaceae, Solanaceae, Umbelliferae, Violaceae, Vitaceae, Zingiberaceae. DISEASES: Damping-off of various seedlings; 'cottony-leak' of cucurbit fruit in storage; 'cottony blight' of turf grasses; root and stalk rot of maize. Other hosts: tobacco, sugar-beet, sugar-cane, papaw, pineapple, ginger, bean and cotton. GEOGRAPHICAL DISTRIBUTION: Africa (Central African Republic, Fernando, Ghana, Kenya, Malawi, Mali, Nigeria, Sierra Leone, South Africa, Southern Rhodesia, Sudan, Togo, Zambia); Asia (Ceylon, China, Formosa, India, Indonesia, Israel, Japan, Java, Malaya, Philippines, Sumatra); Australasia & Oceania (Australia, Hawaii, New Caledonia); North America (Canada, Mexico); Central America & West Indies (Antilles, Jamaica, Puerto Rico); South America (Argentina, Brazil, Peru, Venezuela); Europe Austria, Cyprus, Czechoslovakia, Great Britain, Greece, Holland, Italy, Poland, U.S.S.R., Yugoslavia). (CMI Map 309) TRANSMISSION: Soil-borne. Eggplant fruit become infected when blossom end is in contact with soil (5: 465). Readily isolated from soil using fresh potato cubes treated with streptomycin and pimaricin as baits (43, 1519; 43, 46) or seedling papaw roots in soil containing papaw tissue (43, 1720). Also recorded as seed-borne on tomato and cucurbits but doubtful whether seed-transmitted (see Noble et al., An Annotated List of Seed-Borne Diseases, 1958, pp. 23, 25, 124).


Author(s):  
Genqiang Chen ◽  
Lina Zhu ◽  
Jiaxuan He ◽  
Song Zhang ◽  
Yuanhao Li ◽  
...  

Background: Developing the high-efficiency and low-risk small-molecule green-fungicide is the key to effective control of the plant pathogenic oomycetes. Essential oils play a very important role in novel fungicide discovery for their unique sources and potential target sites. Eugenol, a kind of plant essential oil, was mainly isolated from the unopened and dried flower buds of Syzygium aromaticum of the Myrtaceae family. Due to its unique structural skeleton, eugenol and its derivatives have exhibited a wide range of biological activities. However, study on the synthesis of novel 1-sulfonyloxy/acyloxyeugenol derivatives as fungicidal agents against Phytophthora capsici has not yet been reported. Methods: Twenty-six novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) were prepared and their structures were well characterized by 1H NMR, HRMS, and m.p.. Their fungicidal activity was evaluated against P. capsici by using the mycelial growth rate method. Results: To find novel natural-product-based fungicidal agents to control the plant pathogenic oomycetes, we herein designed and synthesized two series of novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) as fungicidal agents against P. capsici Leonian, in vitro. Results of fungicidal activity revealed that, among all compounds, especially compounds 3a, 3f, and 3n displayed the most potent anti-oomycete activity against P. capsici with EC50 values of 79.05, 75.05, and 70.80, respectively. Conclusion: The results revealed that the anti-oomycete activity of eugenol with the sulfonyloxy group was higher than that with the acyloxy group. It is suggested that the fungicidal activity of eugenol can be improved by introducing the sulfonyloxy group. This will pave the way for further design, structural modification, and to develop eugenol derivatives as fungicidal agents.


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