55 research outputs found
Fungicide sensitivity of selected Verticillium fungicola isolates from Agaricus bisporus farms
Five isolates of Verticillium fungicola, isolated from diseased fruiting bodies of Agaricus bisporus collected from mushroom farms in Serbia during 2002-2003, were studied. By observing their colony morphology under different growth conditions and their pathogenic characteristics, the isolates were identified as V. fungicola var. fungicola. The peat/lime casing was the primary source of infection. Testing of sensitivity to selected fungicides showed that all isolates were highly resistant to benomyl (EC50 values were higher than 200.00 mg/l), moderately sensitive to iprodione (EC50 values were between 11.93 and 22.80 mg/l), and highly sensitive to prochloraz-Mn (EC50 values were less than 3.00 mg/l)
Races and hosts of Pseudomonas syringae pv. tomato in Serbia
During the past few years, frequent appearance of bacterial speck of tomatoes was recorded in several tomato-growing regions in Serbia. A three-year survey of tomato fields in Serbia (2002-2004) resulted in the isolation of numerous bacterial strains, with 30 representative strains selected for further analyses. Based on the results of pathogenicity, biochemical, and physiological tests, all strains isolated from diseased tomato plants were identified as P. syringae pv. tomato. The identity of strains was confirmed by the polymerase chain reaction (PCR), since PCR products of expected size (650 bp) specific for coronatine-producing strains of P. syringae pv. tomato were amplified from all tested strains. Study of the host range of P. syringae pv. tomato strains originating from Serbia confirmed tomato as the sole host. The reaction of tomato differential cultivar Ontario 7710 showed that the Serbian strains belonged to races 0 and 1 of P. syringae pv. tomato
Antifungalna aktivnost etarskih ulja cimeta i karanfiliÄa prema patogenima Å”ampinjona - Cladobotryum dendroides (Bull.) W. Gams & Hooz i Lecanicillium fungicola var. fungicola (Preuss) Hasebrauk
Antifungal activity of two essential oils, cinnamon (Cinnamomum verum J. Presl) and clove (Syzygium aromaticum (L.) Merrill & Perry), was evaluated against Cladobotryum dendroides (Bull.) W. Gams & Hooz, and Lecanicillium fungicola var. fungicola (Preuss) Hasebrauk, the causal agents of cobweb and dry bubble disease of cultivated mushroom. Inhibitory and fungicidal activity of the selected essential oils was assayed using three methods: microdilution, macrodilution fumigant and macrodilution contact method. Comparing all three methods, clove essential oil showed stronger activity than cinnamon against both fungi, having minimum inhibitory concentration (MIC) at the lowest concentrations tested (1.56, 0.02 and 0.1 Āµl ml-1, respectively). However, cinnamon oil was more toxic to L. fungicola var. fungicola then to C. dendroides in all three methods. Both oils exhibited stronger antifungal effects when used in the macrodilution fumigant than in contact method. The results showed that both cinnamon and clove essential oils have the potential for further in vivo experiments against L. fungicola var. fungicola and C. dendroides and indicated a possible use of these oils in integrated disease management in mushrooms.Ispitana je antifungalna aktivnost etarskih ulja cimeta i karanfiliÄa prema Cladobotryum dendroides (Bull.) W. Gams & Hooz, i Lecanicillium fungicola var. fungicola (Preuss) Hasebrauk, prouzrokovaÄima pauÄinaste plesni i suve truleži Å”ampinjona. Antifungalna aktivnost odabranih etarskih ulja testirana je primenom tri razliÄite metode: mikrodilucione, makrodilucione fumigantne i makrodilucione kontaktne metode. Etarsko ulje karanfiliÄa je ispoljilo jaÄi efekat od ulja cimeta na obe gljive primenom sve tri metode, sa minimalnim inhibitornim koncentrecijama pri najnižim testiranim koncentracijama (1,56, 0,02 i 0,1 Āµl ml-1). Ulje cimeta je pokazalo veÄu toksiÄnost prema L. fungicola var. fungicola nego prema C. dendroides. Ispitivana etarska ulja ispoljila su jaÄe antifungalno dejstvo primenjena fumigantno nego kontaktno u makrodilucionoj metodi. Antifungalno delovanje etarskih ulja cimeta i karanfiliÄa in vitro, ukazuje na potencijal za dalja ispitivanja njihove efikasnosti in vivo, kao i moguÄnosti ukljuÄivanja ovih etarskih ulja u integralnu zaÅ”titu jestivih gljiva od bolesti prouzrokovanih mikopatogenim gljivama L. fungicola var. fungicola i C. dendroides
Synthesis and characterization of Na0.4MnO2 as cathode material for aqueous sodium-ion batteries
The application of rechargeable batteries is growing significantly and there is a need for developing cheaper batteries with good performances. Sodium-ion batteries could be a viable option due to higher abundance of sodium against lithium mineral resources, its low price and similar principles intercalate Na+ ions as Li+ ions in lithium-ion batteries. Different materials as manganese oxides and vanadium oxide are used as electrode materials in sodium batteries. Na0.44MnO2 was regarded as one of the most promising cathode materials for sodium-ion batteries due to its high specific capacity and good cyclability. In this work, Na0.4MnO2 was synthesized using glycine-nitrate method (GNM). The structure of synthesized powder was characterized by X-Ray Diffraction (XRD), while the particles morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental mapping was performed by energy-dispersive Xray spectroscopy (EDS). XRD results showed that the phase structure of Na0.4MnO2 was orthorhombic with tunnel structure. TEM and SEM micrographs of obtained powder material showed uniformed rod-like shape particles with the average lengths and widths of 300 nm and 80 nm, respectively and EDS analysis confirmed that the sample contains Na, Mn, and O in an appropriate ration. The electrochemical behavior of Na0.4MnO2 was investigated by cyclic voltammetry (CV) in a saturated aqueous solution of NaNO3 at scan rates from 20 to 400 mVā¢s-1. The initial discharge capacity of Na0.4MnO2 in NaNO3 solution was 50 mAā¢hā¢g- 1, while after 15 cycles its value increased for 9%. while the efficiency (the ratio of the capacity charge and discharge) was amounting to ~ 95%. This indicates that material synthesized by GNM can be used as cathode material in aqueous sodium-ion batterie
Synthesis temperature influence on the structure, morphology and electrochemical performance of NaxMnO2 as cathode materials for sodium-ion rechearchable batteries
The lithium-ion batteries are the most commonly used for energy storage in portable devices. Since lithium is relatively rare on earth but rapidly consumed, it is necessary to find an adequate replacement. Owing to the similar chemical properties of sodium and lithium, but much higher availability, sodium ion batteries are one of the best candidates to replace lithium-ion batteries. A variety of materials such as manganese oxide, vanadium oxide or phosphate can be used as an electrode material (anode and cathode) in sodium ion batteries due to the high ability of intercalation of sodium. In this work, NaxMnO2 powder was synthesized by glycine nitrate method. The precursor powder was annealed for four hours at different temperatures: 800, 850, 900 and 950 Ā°C. The characterization of the obtained materials was carried out using following methods: X-ray diffraction (XRD), scanning electron spectroscopy with energy dispersive X-ray spectroscopy (SEM/EDS) and transmission electron spectroscopy with energy dispersive Xray spectroscopy (TEM/EDS). Electrochemical properties were studied using cyclic voltammetry and chronopotentiometry in an aqueous solution of NaNO3. The layer structured Na0.7MnO2.05 with sheet-like morphology and Na0.4MnO2 with 3-D tunnel structure and rod-like morphology was obtained at 800 oC and 900 oC respectively. Na0.44MnO2 with rod-like morphology was annealed at 900 and 950 oC. 3D-tunnel structure Na0.44MnO2 obtained at 900 oC showed the best electrochemical behaviour in aqueous NaNO3 solution
Analiza koriÅ”tenja preventivne aktivnosti kao odgovora na nadolazeÄu krizu u javnom sektoru
Krizno komuniciranje jedno je od najizazovnijih i najsloženijih podruÄja praktiÄne primjene odnosa s javnoÅ”Äu. Javni sektor se, zbog tromosti sustava, vrlo Äesto spominje i u kontekstu neuÄinkovite komunikacije, a to ukljuÄuje i reaktivan pristup kriznoj komunikaciji. U suprotnosti s ponuÄenim stereotipom, ovaj rad prouÄava studiju sluÄaja krizne komunikacije u kojemu je Äelnik javne institucije primijenio strategiju preventivnog protuodgovora i svojim proaktivnim istupom uzrokovao kriznu situaciju u javnoj instituciji koju je vodio te negativan publicitet. S ciljem ispitivanja ispravnosti ovog pristupa, ujedno i prvog takvog sluÄaja u komunikaciji hrvatskih javnih institucija, analizirane su naslovnice triju najÄitanijih dnevnih listova u Hrvatskoj ā 24sata, VeÄernjeg lista i Jutarnjeg lista ā njihova online izdanja te joÅ” deset najÄitanijih news portala u razdoblju od 24. rujna do 18. listopada, odnosno od sazivanja izvanredne konferencije za medije i poÄetka krize do razrjeÅ”enja Dubravka PonoÅ”a s funkcije direktora Fonda za zaÅ”titu okoliÅ”a i energetsku uÄinkovitost
Synthesis and Characterization of Na0.4MnO2 as a Positive Electrode Material for an Aqueous Electrolyte Sodium-ion Energy Storage Device
Due to the increasing use of batteries in everyday life and in industry, there is a need for developing cheaper batteries than the widely used lithium ion batteries. Lower price and higher abundance of sodium compared to lithium mineral resources intensified the development of Na-ion batteries. Aqueous lithium/ sodium rechargeable batteries have attracted considerable attention for energy storage because they do not contain flammable organic electrolytes as commercial batteries do, the ionic conductivity of the aqueous electrolyte is about two orders of magnitude higher than in non-aqueous electrolyte and the electrolyte salt and solvent are cheaper. Various materials such as manganese oxides, vanadium oxide and phosphates have been used as electrode materials (cathodic and anodic) in sodium batteries due to high sodium intercalation ability in both, organic and aqueous electrolytes. The most frequently used type of manganese oxides are LiāMnāO or NaāMnāO systems due to their tunnel or layered crystal structures which facilitate the lithium/sodium intercalation-deintercalation. In this work, a glycine-nitrate method (GNM) was applied for the synthesis of cathode material Na0.4MnO2
Uticaj tretmana micelije ('semena') Ŕampinjona (Agaricus bisporus L.) - bakterijom Bacillus subtilis QST713 na prinos i zaŔtitu od zelene plesni
A biofungicide based on Bacillus subtilis QST713 was tested for impact on yield and efficacy against a Trichoderma aggressivum f. europaeum T77 strain from Serbia by coating mushroom grain spawn and comparing the results with the chemical fungicide prochloraz manganese in a mushroom growing room. The tested B. subtilis QST713 strain did not inhibit mycelial growth of Agaricus bisporus in plots free of the pathogen, showing an impact on yield of 91.95%, which was not significantly different from an untreated control. As for the efficacy of the fungicides used against T. aggressivum f. europaeum T77, there were no significant differences between a prochloraz manganese casing treatment, and B. subtilis QST713 coating on mushroom grain spawn, as the efficacy was 70.37 and 53.09%, respectively. These results implied that the biofungicide based on B. subtilis could serve as a harmless alternative to synthetic fungicides in mushroom production, especially during serious compost green muold outbreaks caused by T. aggressivum. Furthermore, the biofungicide should be applied alone because an antagonistic reaction was detected between the fungicide prochloraz and B. subtilis QST713.Biofungicid na bazi Bacillus subtilis QST713 je odabran za testiranje uticaja na prinos i efikasnosti u suzbijanju Trichoderma aggressivum f. europaeum T77 iz Srbije, kada je primenjeno za tretiranje micelije ('semena') Å”ampinjona u poreÄenju sa fungicidom prohloraz manganom u oglednom gajiliÅ”tu. Testirani soj B. subtilis QST713 nije inhibirao rast micelije Agaricus bisporus, u tretmanima bez prisustva patogena, sa uticajem na prinos 91.95% i nije se statistiÄki znaÄajno razlikovao od neinokulisane kontrole. U pogledu efikasnosti fungicida u suzbijanju T. aggressivum f. europaeum T77, nije bilo statistiÄki znaÄajne razlike meÄu tretmanima sa fungicidom prohloraz manganom primenjenim na pokrivku i tretmanom B. subtilis QST713 primejenim na miceliju ('seme') Å”ampinjona, sa odgovorajuÄim vrednostima 70.37 i 53.09%. Ovi rezultati ukazuju da se biofungicid na bazi B. subtilis može primenjivati kao alternativa sintetiÄkom fungicidu u proizvodnji Å”ampinjona, posebno kod znaÄajne pojave zelene plesni u kompostu za gajenje Å”ampinjona koju izaziva T. aggressivum. TakoÄe, preporuka je da se biofungicid primenjuje samostalno jer je uoÄena antagonistiÄka reakcija izmeÄu prohloraz mangana i B. subtilis QST713
Efikasnost mandipropamida za suzbijanje prouzrokovaÄa plamenjaÄe krompira u poljskim uslovima
The efficacy of mandipropamid (Revus 250 SC) in controlling Phytophthora infestans in potato was evaluated in field trials. The efficacies of Revus 250 SC in comparison with standard fungicides Quadris (azoxystrobin) were tested in several localities in Serbia (Kasarske Livade, Valjevska Kamenica and Opovo) in 2007 and 2008. Both of the tested fungicides exhibited high efficacy in controlling potato late blight. The differencies in the efficacy of Revus 250 SC (96.3- 99.2%) and Quadris (94.1-95.5%) were insignificant. Our experiments showed that the investigated fungicide was highly effective against P. infestans even under high disease pressure.Ispitivana je efikasnost mandipropamida (Revus 250 SC) za suzbijanje Phytophthora infestans u usevu krompira u poljskim uslovima. Efikasnost preparata Revus 250 SC ispitivana je na nekoliko lokaliteta u Srbiji (Kasarske Livade, Valjevska Kamenica i Opovo) tokom 2007. i 2008. godine. Kao standard poslužio je Quadris (azoksistrobin). Oba ispitivana fungicida su ispoljila visoku efikasnost u suzbijanju prouzrokovaÄa plamenjaÄe krompira. IzmeÄu efikasnosti Revus 250 SC (96.3- 99.2%) i Quadris (94.1-95.5%) nije utvrÄena statistiÄki znaÄajna razlika. NaÅ”i ogledi su pokazali da je ispitivani fungicid visokoefikasan u suzbijanju P. Infestans, Äak i u uslovima jake zaraze
The activity of native Bacillus subtilis strains in control of green mould disease of oyster mushroom (Pleurotus spp.)
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