Efikasnost fungicida u suzbijanju pegavosti lišća cvekle (Cercospora beticola)

Cercospora leaf spot, caused by Cercospora beticola, is significant disease of plants from the family Chenopodiaceae. The disease regularly occurs on sensitive genotypes of beetroot. In order to maximise economical benefits from beetroot production and to achieve high yields, it is necessary to protect crop against this disease by using appropriate fungicides in conditions that promote the infection and disease development. In this this paper, the efficiency of fungicides on the basis azoxystrobin, maneb and flutriafol was examined. The experiment was set up by EPPO standards (EPPO PP1/1 (4)). Fungicides were applied using a back sprayer. The aim of the research was to examine the efficiency of fungicides based on various active substances in field conditions and to determine disease intensity in order to recommend the most effective fungicide. Fungicides with the highest efficiency were on base azoxystrobin (90,5%) and flutrafol (91,4%). The untreated control and plots treated with maneb showed the highest disease intensity: 10,5% and 9,5%, respectively.Pegavost lišća cvekle je jedna od najznačajnijih bolesti biljaka familije Chenopodiaceae. Bolest se redovno javlja posebno na osetljivim genotipovima cvekle. Radi ekonomičnije proizvodnje cvekle i postizanja visokih prinosa, a samim tim i kvaliteta sirovine neophodno je vršiti hemijski zaštitu od ove bolesti, primenom odgovarajućih fungicida. U ovom radu je ispitivana efikasnost fungicida na bazi: azoksistrobina, maneba i flutriafola. Ogled je postavljen po EPPO standardima (EPPO PP1/1 (4)). Tretiranja su obavljena pomoću leđne prskalice. Zadatak istraživanja je bio da se u poljskim uslovima ispita efikasnost fungicida na bazi različitih aktivnih materija kao i da se utvrdi intenzitet oboljenja po varijantama, a cilj davanje preporuke o najefikasnijoj varijanti primene fungicida. Fungicidi sa najvećom efikasnosti po varijanti su bili na bazi azoksistrobina (90,5%) i flutriafola (91,4%), a intenzitet oboljenja je bio najmanji na varijanti tretiranom flutriafolom (0,9%) i azoksistrobinom (1,0%), dok je na kontrolnoj varijanti bio najveći (10,5%), kao i na varijanti tretiranom manebom (9,5%)

Značaj prvog prolećnog tretiranja voćaka i vinove loze

Treatment of fruit trees and grape vines at the onset of the growing season is a highly important operation in fruit and grape production, leading to a reduction in the reproductive potential of a large number of pests as well as to a decrease in pathogen inoculum density. Timely inspection of fruit trees and grape vines over the winter indicates the need for early spring treatments at the bud swell and bud burst stages. During the 2011-2012 period, winter inspections were performed to determine the presence of harmful overwintering insects and mites in apple plantings in the Town of Čačak. Results show a high abundance of Aphididae, Geometridae and Acarinae.Tretiranje voćaka i vinove loze u vremenu kretanja vegetacije je veoma značajna mera u tehnlologiji proizvodnje voća i grožđa. Ovim tretiranjem se na početku vegetacije smanjuje potencijal razmnožavanja velikog broja štetočina i količina inokuluma prouzrokovača bolesti. Blagovremeno sprovođenje zimskih pregleda voćaka i vinove loze ukazuje na potrebu sprovođenja prvih prolećnih tretiranja u fenofazi bubrenja i pucanja pupoljaka. U periodu 2011-2012. godine zimskim pregledima utvrđivano je prisustvo prezimljavajućih formi štetnih insekata i grinja u zasadima jabuka na teritoriji Grada Čačka. Dobijeni rezultati ukazuju na visoku brojnost Aphididae, Geometridae i Acarinae

Noviji nalazi i stepen pojave prstenaste nekroze krtola krompira (potato virus y, pvyntn) u Srbiji

Potato virus Y i.e. its necrotic strain (PVYNTN) is among the most economically harmful agents of potato diseases in Serbia and in many countries across the world. Damage caused by the virus involves reduced yields of infected plants, its spread i.e. a high percentage of infected plants at the country level and a high rate of annual infections (infestation of healthy plants) during the growing season. In most widely grown potato cultivars, the necrotic strain of potato virus Y causes symptoms only on aboveground parts, depending on cultivar and time of infection (primary and secondary). The necrotic strain of potato virus Y causes additional problems to some potato cultivars including symptoms of necrotic ringspot disease on tubers, resulting in their reduced quality or rendering them unmarketable. Experience shows that these are mostly cultivars that have a high dry matter content in tubers and that are processed into potato chips. This study presents results on the susceptibility of some potato cultivars to tuber necrotic ringspot disease as well as on the incidence of the disease under conditions characterised by a high potential for infection with the necrotic strain of potato virus Y.Y virus odnosno nekrotični soj (PVYNTN) ovog virusa je jedan od ekonomski najštetnijih prouzrokovača bolesti krompira u Srbiji i mnogim zemljama sveta. Štetnost virusa se ogleda u smanjenju prinosa zaraženih biljaka, njegovoj raširenosti odnosno visokom procentu zaraženih biljaka krompira na području države i velikoj brzini jednogodišnjeg širenja (zaražavanja zdravih biljaka) u toku vegetacije. Nekrotični soj Y virusa, na većini široko rasprostranjenih sorti u proizvodnji krompira, prouzrokuje simptome samo na nadzemnom delu biljke krompira u zavisnosti od sorte kromira i vremena zaraze (primarna i sekundarna). Nekrotični soj Y virusa krompira predstavlja dodatni problem za neke sorte krompira na čijim krtolama prouzrokuje simptome prstenaste nekroze što umanjuje njihov kvalitet ili ih čini tržišno neupotrebljivim. Dosadašnja iskustva govore da su to uglavnom sorte sa visokim sadržajem suve materije u krtolama i koje se koriste za preradu u oplemenjene proizvode. U ovo radu su prikazani rezultati osetljivosti nekih sorti krompira na prstenastu nekrozu krtola i stepen pojave bolesti u našim uslovima koje karakteriše visok infekcioni potencijal nekrotičnim sojem Y virusa

Pojava, štetnost i suzbijanje krompirovog moljca (Phthorimaea operculella)

Potato tuber moth, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae), is a damaging pest occurring in warm, tropical and subtropical regions. In the last several years, it has also been present in Serbia, causing serious damage to potatoes. Its harmfulness involves damage to potato tubers which renders them useless for marketing, leading to complete yield loss. This pest is also important in terms of the complexity of its control. In Serbia, until five years ago, this pest was known only through literature. The first official data on its presence in Serbia i.e. in the Leskovac region date back to 2011. The potato tuber moth was first recorded in 2008 (Leskovac), and its presence in other areas of Serbia was first reported in 2011. During 2015, extensive damage from this insect was recorded on the potato crop in Čačak, particularly in the lowlands, where potatoes are intensively grown for high yields, as well as in other parts of the country. This pest requires complex control practices. It is only through the use of both preventive and direct control measures by all potato growers on a large scale that success in pest control and damage reduction can be expected.Krompirov moljac, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae), je štetočina toplih, tropskih i subtropskih regiona sveta. U poslednjih nekoliko godina je prisutan i u Srbiji gde pričinjava velike štete na krompiru. Štetnost moljca se ogleda u oštećenju krtola koje postaju tržišno neupotrebljive do potpunog propadanja celokupnog prinosa. Ova štetočina je značajna i po složenosti njenog suzbijanja. Kod nas se o ovoj štetočini do pre pet godina znalo samo iz literature. Prvi zvanični podaci o prisustvu štetočine kod nas, na području Leskovca, potiču iz 2011. godine. Prvi nalaz moljca potiče iz 2008. godine (Leskovac), a prema nekim podacima štetočina se javlja od 2011. godine i u drugim područjima u Srbiji. Tokom 2015. godine evidentirane su ogromne štete na krompiru od ovog insekta na teritoriji Čačka, posebno u ravničarskom delu gde se intenzivno gaji krompir i gde se postižu visoki prinosi, kao i u drugim delovima Srbije. Suzbijanje ove štetočine je veoma složeno. Samo primenom svih, preventivnih i direktnih mera od strane svih uzgajivača krompira, na većem području, se mogu očekivati rezultati u suzbijanju štetočine i smanjenju šteta

Istorijat gajenja krompira u Crnoj Gori

The beginning of potato growing is associated to Incas. This ancient civilization cultivated potatoes of all shapes, colours and flavours 10,000 years ago in the Andes. For communities that lived in the Andes at that time, these plants were the most important source of food. For the rest of the world, until the XVI century, potato was unknown culture. Spanish conqueror Pizarro brought potatoes from South America to Europe in 1562. As a botanical curiosity, first potatoes arrived to Spain, and were later on spread to other countries of Europe. For many years after introduction, potato was grown as an ornamental plant, until the Europeans accepted it as an edible plant. Growing of potatoes in Montenegro begins in late eighteenth century, similar as in other Balkan countries. Bishop Petar I Petrović Njegoš brought potatoes in Montenegro probably in early 1786. Due to favourable climatic and soil conditions, the areas planted with potatoes were quickly spread in Montenegro. Expansion of the areas planted with potatoes significantly improved the life of local population, and this culture, due to its enormous importance as a food, quickly got the epithet of “life-saving food”. Therefore, potatoes became, for a very short time, the leading agricultural crop and this status is maintained up to the present day.Početak gajenja krompira vezuje se za Inke. Ova drevna civilizacija je prije 10.000 godina, na Andima, gajila krompir svih oblika, boja i ukusa. Za zajednice koje su u to vrijeme živjele na Andima ova biljna vrsta je bila najznačajniji izvor hrane. Za ostatak svijeta, sve do XVI vijeka, krompir je bio nepoznata kultura. Iz Južne Amerike u Evropu krompir je donio španski osvajač Pizarro 1562. godine. Kao botanički kuriozitet krompir je prvo stigao u Španiju, a odatle se kasnije proširio i u ostale zemlje Evrope. Godinama nakon unošenja krompir je gajen kao ukrasna biljka, sve dok ga Evropljani nijesu prihvatili kao jestivu namirnicu. Gajenje krompira u Crnoj Gori počinje krajem XVIII vijeka, manje-više kao i u ostalim balkanskim državama. Krompir je u Crnu Goru donio vladika Petar I Petrović Njegoš, najvjerovatnije početkom 1786. godine. Zahvaljujući veoma povoljnim klimatskim i zemljišnim uslovima površine pod krompirom u Crnoj Gori su se brzo širile. Širenjem površina pod krompirom značajno je poboljšan život lokalnog stanovništva, pa je ova kultura, zbog svog ogromnog prehrambenog značaja, vrlo brzo dobila epitet spasonosne hrane. Zbog toga je krompir, za veoma kratko vrijeme, postao vodeća poljoprivredna kultura, a taj status je zadržao i do današnjih dana

Physiological normoxia and absence of EGF is required for the long-term propagation of anterior neural precursors from human pluripotent cells

Widespread use of human pluripotent stem cells (hPSCs) to study neuronal physiology and function is hindered by the ongoing need for specialist expertise in converting hPSCs to neural precursor cells (NPCs). Here, we describe a new methodology to generate cryo-preservable hPSC-derived NPCs that retain an anterior identity and are propagatable long-term prior to terminal differentiation, thus abrogating regular de novo neuralization. Key to achieving passagable NPCs without loss of identity is the combination of both absence of EGF and propagation in physiological levels (3%) of O2. NPCs generated in this way display a stable long-term anterior forebrain identity and importantly retain developmental competence to patterning signals. Moreover, compared to NPCs maintained at ambient O2 (21%), they exhibit enhanced uniformity and speed of functional maturation, yielding both deep and upper layer cortical excitatory neurons. These neurons display multiple attributes including the capability to form functional synapses and undergo activity-dependent gene regulation. The platform described achieves long-term maintenance of anterior neural precursors that can give rise to forebrain neurones in abundance, enabling standardised functional studies of neural stem cell maintenance, lineage choice and neuronal functional maturation for neurodevelopmental research and disease-modelling

Mogućnost primene insekticida i mineralnih ulja u sprečavanju transmisije važnijih virusa krompira koji se prenose biljnim vašima

Viruses occurring in Serbia and other countries in the region are a huge problem constraining seed potato production. At lower altitudes, in lowland and hilly regions, where table potato production is widely distributed, more than 50% of healthy plants become infected with potato virus Y during one growing season. Under these conditions, seed potato production is hindered due to a high infection pressure of potato virus Y which spreads far more rapidly compared to leaf roll virus, virus S and other viruses hosted by this plant species. This study tended to clarify a frequent dilemma regarding the use of insecticides in preventing the infection of healthy plants with potato virus Y and leaf roll virus, given the oral and written recommendations from pesticide manufacturers, agronomists and scientists in the field of crop protection arising from a logical conclusion that aphid vector control results in virus transmission control. The present findings, which are in agreement with reports of authors from other countries, show that the use of insecticides is ineffective in preventing potato virus Y which is nonpersistently transmitted by aphids from an external source of infection. However, insecticides can exhibit efficacy in preventing potato virus Y transmission from infected plants to healthy plants within a crop, which can have an overall positive effect only if seed potato is grown in areas that have no external source of infection. The present results and those of other authors show that insecticides are effective in preventing the infection of healthy plants with persistently transmitted leaf roll virus. Mineral oils provide effective control of potato virus Y by preventing the infection of potato plants with the virus. They can be combined with other management practices to protect seed potato crops against the virus. Given the fact that the initial first-year infection of healthy potato plants with virus Y in relation to leaf roll virus is approximately 10-20:1 under conditions in Serbia, and that the use of insecticides fails to ensure protection against PVY, this practice cannot have any positive effect on virus control under high infection pressure conditions.Virusi u Srbiji i državama regiona predstavljaju veliki problem i ograničavajući činilac u proizvodnji semenskog krompira. Na nižim nadmorskim visinama, u ravničarskim i brdskim područjima, gde je raširena proizvodnja konzumnog krompira, Y virusom se zarazi u toku jedne vegetacije više od 50% zdravih biljaka. U takvim uslovima nije moguća proizvodnja semenskog krompira zbog visokog infekcijskog pritiska Y virusom krompira koji se znatno brže širi u odnosu na virus uvijenosti lišća, S virus krompira i druge viruse čiji je ova biljka domaćin. U ovom radu smo pokušali razjasniti dilemu, koja se često nameće, da li ima efekta primena insekticida u cilju sprečavanja zaraze zdravih biljaka Y i virusom uvijenosti lišća krompira s obzirom na usmene i pisane preporuke, proizvođača pesticida, agronoma i naučnih radnika iz oblasti zaštite bilja, koje nastaju kao posledica logičkog zaključivanja da suzbijanjem vektora, biljnih vaši, suzbijamo i prenošenje virusa. Rezultati naših istraživanja, što je u saglasnosti i sa rezultatima istraživača iz drugih zemalja, pokazuju da primena insekticida nema efekta na sprečavanje prenošenja Y virusa, koji se vašima prenosi na neperzistentan način, sa spoljnog izvora zaraze. Međutim, primena insekticida može imati efekta u sprečavanju prenošenja Y-VKr sa zaraženih na zdrave biljake unutar useva krompira, a to može imati ukupan pozitivni efekat samo ako se semenski krompir uzgaja u područjima bez spoljnog izvora zaraze. Naši, i rezultati drugih istraživača pokazuju da primena insekticida radi sprečavanja zaraze zdravih biljaka virusom uvijenosti lišća koji se prenosi na perzistentan način ima efekta. U zaštiti biljaka krompira od infekcije Y-VKr su efikasna mineralna ulja koja sprečavaju infekciju biljaka ovim virusom i koja se mogu koristiti sa drugim merama u sistemu zaštite semenskog useva krompira od ovog virusa. S obzirom na činjenicu da je, u našim uslovima, početna jednogodišnja zaraza zdravih biljaka krompira Y virusom u odnosu na virus uvijenosti lišća približno 10-20:1, a primena insekticida ne osigurava zaštitu od Y-VKr, onda ova mera ne može imati nikakvog pozitivnog efekta u suzbijanju virusa u uslovima visokog infekcijskog pritiska

Rhagoletis cerasi Loew (Diptera, Tephritidae) – biološke karakteristike, štetnost i suzbijanje

The European cherry fruit fly, Rhagoletis cerasi Loew (Diptera: Tephritidae), is a highly destructive pest in sweet and sour cherry orchards with a distribution area throughout Europe and the temperate regions of Asia. It occurs regularly in all production regions of these fruit species in Serbia, damaging up to 10% of cherries in commercial production, while damage can go up to 100% in orchards and on solitary threes unprotected by control measures. In Serbia, European cherry fruit fly most often attacks and damages fruits of the lateripening cultivars of sweet cherry (Van, Stela, Hedelfinger, Bing, Lambert, Drogan’s Yellow). After a sweet cherry harvest, adults migrate to sour cherry where they continue feeding and ovipositing in half-mature sour cherries (prevailingly the domestic ecotype Oblačinska). During their activity period, larvae damage the fruits, so that they can no longer be consumed either fresh or processed. The high percentage of sour cherries damaged by R. cerasi has become a factor limiting exports because the intensity of infestation of this fruit exceeds permissible limits. Pesticide use for controlling this pest, especially in integrated production, is based on a very poor selection of insecticides which cause problems with residual ecotoxicity. Consequently, alternative measures for controlling European cherry fruit fly have been intensively studied over the past few years. This work surveys up-to-date results of various studies on the European cherry fruit fly as a very important pest in Serbia and other South and Mid-European countries. The work contains detailed descriptions of its biological characteristics, flight phenology, infestation intensity and possibilities of fly control in sweet and sour cherry production areas.Evropska trešnjina muva, Rhagoletis cerasi Loew (Diptera: Tephritidae), veoma destruktivna štetočina u zasadima trešnje i višnje, rasprostranjena je širom Evrope i u umerenim regionima Azije. Redovno se javlja u svim proizvodnim područjima ovih vrsta voćaka u Srbiji, oštećujući do 10% plodova u komercijalnoj proizvodnji, a u zasadima i na pojedinačnim stablima gde se ne sprovode mere zaštite i do 100%. Trešnjina muva u uslovima Srbije najčešće napada i oštećuje plodove kasnih sorata trešnje (Van, Stela, Hedelfinger, Bing, Lambert, Drogan’s Yellow). Po završenoj berbi trešanja imago prelazi na višnju i nastavlja sa ishranom i ovipozicijom u poluzrele plodove višnje (najzastupljenija: domaći ekotip oblačinska višnja). Svojim aktivnostima larve oštećuju plodove i oni postaju neupotrebljivi za ishranu u svežem stanju, ali i za preradu. Visok procenat oštećenih plodova višnje delovanjem R. cerasi je ograničavajući faktor izvoza, jer je intenzitet napada na plodovima iznad dozvoljene granice. Primena pesticida za kontrolu ove štetočine, posebno u integralnoj proizvodnji, ograničena je na veoma mali izbor insekticida, čija se primena vezuje za probleme ekotoksičnosti ostataka. Zbog toga se poslednjih godina sve više proučavaju alternativne metode za kontrolu populacije trešnjine muve. U radu su prikazani dosadašnji rezultati proučavanja evropske trešnjine muve, vrlo značajne štetočine u Srbiji i drugim zemljama južne i srednje Evrope. Detaljno su opisane biološke karakteristike, fenologija leta, intenzitet napada i mogućnosti suzbijanja muve u područjima gajenja trešnje i višnje

Uticaj praćenja brojnosti i vrsta biljnih vaši kao vektora virusa na proizvodnju semenskog krompira u Srbiji

Aphids are the most important vectors of potato viruses during the crop’s growing season. The most widespread and damaging viruses, the potato virus Y and potato leaf roll virus, are transmitted by aphids in non-persistent and persistent manner, respectively. The two viruses cause the greatest concern of potato producers and a great constraint to seed potato production in Serbia, the region and across the world. Potato virus Y is particularly harmful, given its distribution and spreading rate. Seed potato production systems under well-managed conditions involve a series of virus control measures, including the monitoring of outbreaks of winged aphids, their abundance and species composition, in order to forecast virosis, i.e. potential plant and tuber infection periods. Monitoring the aphid vectors of potato viruses enables determination of optimum dates for haulm destruction when higher than normal numbers of winged aphids as vectors of economically harmful diseases have been observed. Haulm destruction in a potato crop reduces the risk of plant infection and virus translocation from the aboveground parts to tubers, thus keeping the proportion of infected tubers within tolerance limits allowed for certain categories of seed potatoes. This practice has positive effects if used in combination with other viral disease control measures; otherwise, it becomes ineffective. This paper provides an integral analysis of the effects and role of monitoring outbreaks of aphids, their abundance and species composition in timing haulm growth termination to prevent plant infection, virus translocation and tuber infestation in potato crops in Serbia and the wider region.Biljne vaši su najznačajniji vektori virusa krompira u toku vegetacije. Od važnijih virusa u smislu rasprostranjenosti i štetnosti, Y virus krompira biljne vaši prenose na neperzistentan, a virus uvijenosti lišća krompira na perzistentan način. Ova dva virusa predstavljaju najveći problem u proizvodnji krompira i ograničavajući su činilac proizvodnje semenskog krompira u Srbiji i regionu i mnogim državama sveta. Posebno je štetan Y virus s obzirom na njegovu rasprostranjenost i brzinu širenja. U sistemu proizvodnje semenskog krompira, u dobro uređenom i kontrolisanom semenarstvu, jedna u nizu mera suzbijanja virusa jeste i monitoring biljnih vaši odnosno praćenje vremena pojave, brojnosti i vrsta krilatih formi biljnih vaši radi prognoze viroza. Time se prognozira vreme mogućih infekcija biljaka i zaražavanja krtola. Monitoringom biljnih vaši, vektora virusa, odredjuje se optimalno vreme za uništavanje nadzemne mase krompira kada se pojave krilate vrste vaši koje su vektori ekonomski štetnih virusa u većem broju od uobičajenog. Uništavanjem nadzemne mase krompira smanjuje se rizik od eventualne zaraze biljaka i translokacije virusa iz cime u krtolu i na taj način se sprečava da procenat zaraženih krtola pređe granicu dozvoljenu za određenu kategoriju semenskog krompira. Ova mera ima pozitivnog efekta ako se primenjuje uz druge mere koje su značajne za suzbijanje viroza. Ako se druge mere ne sprovode, onda ova mera može biti bez ikakvog efekta. Sadržaj ovoga rada predstavlja integralno razmatranje problematike efekta i značaja praćenja vremena pojave, brojnosti i vrsta biljnih vaši na vreme prekida vegetacije krompira radi sprečavanja zaraze biljaka, translokacije virusa i zaražavanja krtola u uslovima Srbije i regiona

Otpornost jagode prema biljnoj vaši Chaetosiphon fragaefolii Cockerell (Homoptera: Aphididae)

Cross-sections of leaf blades and petioles of different strawberry genotypes exhibiting different levels of resistance to Chaetosiphon fragaefolii were studied using the paraffin method, and staining with safranin, crystal violet and light green. Besides thicker cell walls of the cortex collenchyma in the more resistant genotypes, and a proportionally wider collenchyma than parenchyma in the cortex, their midribs are also encircled by a ring of more intensely stained lignified cells forming a physical ring. This stain reaction of cells to safranin and crystal violet occurs also in lateral vascular bundles, as well as in leaf palisade tissue. The tissue cross-sections of the sensitive genotypes revealed a predominance of green on the cellulose cell walls and protoplasts due to the reaction to light green SF, while stain reactions to safranin and crystal violet were not evidenced.Parafinskom metodom i bojenjem preseka safraninom, kristal ljubičastim i svetlo zelenim SF proučavana je građa preseka liske i lisne drške genotipova jagode različite otpornosti prema Ch. fragaefolii. Kod otpornijih genotipova pored debljih zidova ćelija kolenhima primarne kore i većeg udela kolenhima u odnosu na parenhim u primarnoj kori, oko glavnih provodnih snopova postoji prsten jače obojenih lignifikovanih ćelija koje obrazuju mehaničku saru. Ova bojena reakcija ćelija na safranin i kristal ljubičasto postoji i na sitnijim provodnim snopovima i u palisadnom tkivu lista. Na presecima tkiva osetljivih genotipova dominira zelena boja celuloznih zidova ćelija i protoplasta zbog bojene reakcije na svetlo zeleno SF, dok su odsutne bojene reakcije na safranin i kristal ljubičasto