oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Use of carnauba based carrier for copper sprays reduces infection by Xanthomonas citri subsp. citri and Diaporthe citri in Florida commercial grapefruit groves  [PDF]
Jan Narciso, Wilbur Widmer, Christopher Ference, Mark Ritenour, Ricardo Diaz
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.37117
Abstract: Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a bacterial disease of citrus and results in peel blemishes rendering fresh fruit unsalable. Xcc is most active in warm, wet Florida summers where tissues are infected during periods of active growth. Melanose, caused by Diaporthe citri, is common in citrus producing countries, but, like canker, is only important for fresh market fruit. To control canker and melanose, Florida growers spray trees with copper formulations (Cu), but these sprays are removed by strong rains and intense radiation of Florida summers. A study was undertaken in FL commercial grapefruit groves in 2009 and 2010 to assess the efficiency of a spray combining copper with a specially formulated, hydrating wax (WashGard?) (WG). Using a 21-day spray schedule for the season, fruit were sprayed with WG + Cu, Cu and Control (no spray). Fruit from trees sprayed with WG + Cu had approximately 10 and17% more canker free fruit in 2009 and 2010 respectively compared to trees sprayed with copper alone. Compared to control trees the canker free fruit incidence was increased by ≈10% in 2009 and 57% in 2010. For melanose there was 40% more disease free fruit (treated) over fruit from trees with no treatment in 2009 and approximately 20% more in 2010. Controlling infection with this spray significantly reduces citrus canker and melanose, increasing the percentage of marketable fruit.
Caracteriza??o molecular através da técnica fAFLP de isolados de Diaporthe citri
Nozaki, Márcia de Holanda;Camargo, Margarete;Lemos, Eliana Gertrudes Macedo;Aukar, Ana Paula de Andrade;Barreto, Modesto;
Summa Phytopathologica , 2006, DOI: 10.1590/S0100-54052006000200008
Abstract: citriculture is a market in expansion specially in sao paulo state, whose importance in the economy is already recognized. like any other cultivated species, the increase of planted areas contributes to an increase in disease problems. thus, many diseases affect citrus species, including melanose, caused by diaporthe citri (wolf.), to which most commercial varieties are susceptible to the disease. knowledge of the intra-specific diversity is important when selecting varieties for resistance. this study evaluated the genetic variability among diaporthe citri isolates, obtained from different geographical regions, varieties, and parts of the plant using molecular markers. amplified fragment length polymorphism (aflp) markers were used to characterize ten isolates of this pathogen. genomic dnas extracted from mycelial mass were used in amplification reactions. faflp allowed separation of the isolates into four distinct groups. however, genetic similarity analysis did not group isolates by location, variety or part of the plant.
Caracteriza??o de Diaporthe citri em diferentes meios de cultura, condi??es de temperatura e luminosidade
Nozaki, Márcia de H.;Camargo, Margarete;Barreto, Modesto;
Fitopatologia Brasileira , 2004, DOI: 10.1590/S0100-41582004000400012
Abstract: the mycelial growth of ten diaporthe citri isolates was studied comparing six culture media (oatmeal-agar, malt-peptone-agar, potato-dextrose-agar, orange leaf-dextrose-agar, lemon leaf-dextrose-agar, corn-agar) under 22 ± 2 °c and 12 h light/12 h dark. the evaluation of the mycelial growth of the fungi was also compared under five different temperatures (10, 15, 20, 25 and 30 °c) and three different luminosity conditions (12 h light/12 h dark, continuous light and continuous dark) on potato-dextrose-agar media (pda). variations in pycnidial and mycelial mass production were observed in the different media, temperature and luminosity conditions tested. for most isolates, oatmeal-agar, 20-25 °c and continuous light promoted best sporulation. the pycnidial production was greater under continuous light. the pathogenicity test was made by inoculating mycelial discs of 5 mm on sores made in twigs and stem of citrus (citrus spp.) cultivars. after seven days, gum exudation was observed in plants that were inoculated with the isolates, but not on control. all isolates were pathogenic, but pc2 and pc5 caused bigger lesions in plants.
Caracteriza o de Diaporthe citri em diferentes meios de cultura, condi es de temperatura e luminosidade  [cached]
Nozaki Márcia de H.,Camargo Margarete,Barreto Modesto
Fitopatologia Brasileira , 2004,
Abstract: Estudou-se o crescimento micelial de dez isolados de Diaporthe citri, utilizando-se seis meios de cultura (aveia-ágar, maltose-peptona-ágar, batata-dextrose-ágar, folha de laranja-dextrose-ágar, folha de lim o-dextrose-ágar, milho-ágar) à temperatura de 22 ± 2 °C e fotoperíodo de 12 h claro/12 h escuro. O cultivo em meio de batata-dextrose-ágar (BDA) foi conduzido em cinco temperaturas diferentes (10, 15, 20, 25 e 30 °C). Três diferentes regimes de luminosidade (12 h claro/12 h escuro, claro contínuo, escuro contínuo) foram utilizados para verificar o crescimento do fungo. Foram observadas varia es na produ o de picnídios e de massa micelial nos diferentes meios de cultura, temperaturas e regimes de luminosidade testados, sendo que, para a maioria dos isolados, o meio de cultura de aveia-ágar, a faixa de 20 a 25 °C e o regime de claro contínuo induziram maior crescimento micelial. A produ o de picnídios foi maior para o regime de luz contínua. O teste de patogenicidade foi feito por inocula o de discos de micélio de 5 mm de diametro em ferimentos em ramos e caule de lim o 'Feminelo' (Citrus limon) enxertado em citrumelo 'Swingle'(Poncirus trifoliolata x Citrus paradisi) e plantas de lim o 'Cravo' (C. limonia) enxertados com laranja 'Valência' (C. sinensis). Após sete dias, houve o aparecimento de exsuda o de goma nas plantas inoculadas com os isolados, mas n o na testemunha. Todos os isolados mostraram-se patogênicos, sendo os isolados PC2 e PC5, os que causaram comprimento de les o maior nas plantas.
In vitro and in vivo screening of fungicides for controlling citrus melanose caused by Diaporthe citri
防治柑橘黑点病药剂的离体和田间筛选

CHEN Guo-qing,JIANG Li-ying,XU Fa-san,LI Hong-ye,
陈国庆
,姜丽英,徐法三,李红叶

浙江大学学报(农业与生命科学版) , 2010,
Abstract: 为探明防治柑橘黑点病(Diaporthe citri,无性态为Phomopsis citri)的最佳药剂,在实验室条件下比较了戊唑醇、苯醚甲环唑、咪鲜胺锰盐3种麦角甾醇合成抑制剂类杀菌剂和代森锰锌对黑点病菌菌丝生长和分生孢子萌发的抑制效果.结果表明:4种药剂抑制黑点病菌菌丝生长的有效中浓度(EC50)依次为0.250,0.497,0.113和1.800 μg·mL-1;抑制该病原菌孢子萌发的EC50依次为72.893,42.746,20.701和0.970 μg·mL-1.药剂田间防效试验表明:代森锰锌可湿性粉剂600倍稀释液使用5次和3次对黑点病的防治效果分别达79.1%和63.6%,明显优于同样次数和推荐剂量的杀菌剂戊唑醇、苯醚甲环唑和咪鲜胺锰盐.因此,可以认为在这4种药剂中代森锰锌是防治柑橘黑点病的最佳药剂.
柑橘黑点病菌种群对代森锰锌的敏感性评价及其替代药剂的筛选
Sensitivity evaluation of Diaporthe citri populations to mancozeb and screening of alternative fungicides for citrus melanose control
 [PDF]

刘欣,王明爽,梅秀凤,姜丽英,韩国兴,李红叶,Liu Xin,Wang Mingshuang,Mei Xiufeng,Jiang Liying,Han Guoxing,Li Hongye
- , 2018, DOI: 10.13802/j.cnki.zwbhxb.2018.2016175
Abstract: 为明确柑橘黑点病菌种群对代森锰锌的敏感性及筛选更高效的防治药剂,采用孢子萌发法测定来源于黄岩、衢州、梅州和南丰4个生产果园种群和1野生种群,共221个柑橘黑点病菌菌株对代森锰锌的敏感性;并在离体、温室和果园条件下,评价百菌清和克菌丹等药剂的抑菌活性和防治效果。结果显示,南丰种群和衢州种群对代森锰锌的EC50分别为1.11、1.01 μg/mL,显著高于野生种群0.90 μg/mL,但最不敏感菌株抗性水平仅为1.8,小于5;百菌清和克菌丹对孢子萌发抑制效果显著优于代森锰锌,温室防效与代森锰锌相当;苯醚甲环唑抑制孢子萌发效果显著低于代森锰锌、百菌清和克菌丹,但抑制菌丝生长的效果显著较好。代森锰锌与苯醚甲环唑以质量比4∶1混合对抑制菌丝生长有增效作用,与矿物油以1∶1 250及1∶6 250混合对抑制病菌孢子萌发有增效作用。结果表明我国柑橘黑点病菌种群仍对代森锰锌敏感,代森锰锌仍为有效防治药剂;添加适量苯醚甲环唑或矿物油有提升代森锰锌防效的潜力。
To investigate whether Diaporthe citri populations are still sensitive to mancozeb, and to screen more efficient fungicides for citrus melanose control, the sensitivity of 221 D. citri isolates of four commercial orchard populations and one wild population to mancozeb were tested by using the method of inhibition of conidial germination. The antifungal activities and control effect of the fungicides chlorothalonil and captan were assessed under in vitro, greenhouse, and field conditions. The results showed that the average EC50 values of Nanfeng or Quzhou population were 1.11 and 1.01 μg/mL, respectively, which was significantly higher than that of the wild population with an EC50 of 0.90 μg/mL. However, the resistance factor of the least sensitive isolate in this research was 1.8, less than 5. Chlorothalonil or captan had a better effect than mancozeb in inhibiting the conidial germination of D. citri. When applied as protectants before the inoculation, chlorothalonil, captan and mancozeb showed similar control effects against melanose. Though difenoconazole showed lower inhibitory effect against the conidial germination of D. citri, it had a higher inhibitory effect on mycelial growth than mancozeb, chlorothalonil and captan. When mancozeb and difenoconazole were mixed at the mass ratio of 4∶1, their synergistic effect on mycelial growth was exhibited in vitro. Mineral oil could increase the activity of mancozeb and synergistic effect against conidial germination was exhibited when mancozeb and mineral oil were mixed with the mass ratio of 1∶1 250 or 1∶6 250. Taken together, the populations of D. citri in China are still sensitive to mancozeb and mancozeb remains to be an efficient fungicide for melanose control. Adding a moderate amount of difenoconazole or mineral oil into mancozeb may further promote its control effect against citrus melanose.
Grapefruit Pamplemousse  [cached]
Catharine Savage?Brosman
Revue LISA / LISA e-journal , 2007, DOI: 10.4000/lisa.481
Abstract: Tossing a grapefruit in the air to catch it, as I skippast squash and eggplants to my shopping cart,I can imagine juggling two or three—just possible, perhaps—or five or six: why not,since it’s a fantasy? Or holding like a godone golden planet, as I swing, beneath a tentof stars, from a trapeze, then pitch the orb,a flaming meteorite, in softball fashionto another acrobat below. Or even, most amazing,tightrope-walking, with a grapefruitin each hand as balance, and the crowd in silence,breathl...
Microencapsulation of Flavors in Carnauba Wax  [PDF]
Jelena Milanovic,Verica Manojlovic,Steva Levic,Nevenka Rajic,Viktor Nedovic,Branko Bugarski
Sensors , 2010, DOI: 10.3390/s100100901
Abstract: The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.
Drug interactions with grapefruit juice  [cached]
Prasad Tandale
Pharmaceutical Reviews , 2007,
Abstract: Concomitant intake with grapefruit juice increases the concentrations of many drugs in humans. The effect seems to be mediated mainly by suppression of the cytochrome P450 enzyme CYP3A4 in the small intestine wall. This results in a diminished first pass metabolism with higher bioavailability and increased maximal plasma concentrations of substrates of this enzyme. The effect was most pronounced in drugs with high first pass degradation. The components of grapefruit juice which are the most probable causes of the interaction are furanocoumarins derivatives, but the flavonoid naringenin may also contribute. Concomitant grapefruit juice intake does not generally decrease the variability of drug pharmacokinetic parameters. Therefore, it is recommended that patients abstain from drinking grapefruit juice when they are taking a drug that is extensively metabolised, unless a lack of interaction has already been demonstrated for that drug. It is also recommended that drugs possibly interacting with grapefruit juice should be appropriately labelled.
Drug interactions with grapefruit  [PDF]
Bojani? Zoran ?.,Bojani? Novica Z.,Bojani? Vladmila V.
Medicinski Pregled , 2010, DOI: 10.2298/mpns1012805b
Abstract: Introduction. The concentration of many orally given medications may be affected by grapefruit or grapefruit juice consumption. It may result in numerous harmful effects. Interaction of grapefruit with drugs. Taking only one cup of juice may induce interactions with different drugs even during the period of a few days. The effect is induced by suppression of cytochrome P450 isoenzyme CYP3A4 in the intestinal wall. The Latin name of grapefruit, Citrus paradisi, is quite opposite to the effects which could be induced by taking grapefruit and some medications at the same time. It is necessary to avoid taking grapefruit with the drugs whose pharmacokinetics could be altered by the active principles found in that fruit. Discussion. The coloured grapefruit contains less furanocoumarins, but there is no difference in induction and intensity of pharmacokinetic interaction with drugs related to its colour. Other citrus fruits (orange, lemon) do not have such effects, but some other fruits (pomegranate, stella fruit, banpeiyu, hassaku, takaoka-buntan and kinkan) exert inhibitory effects on the activity of cytochrome P450 isoenzyme.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.