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In autumn 2018, daffodil (narcissus) plants with basal bulb rot were noticed in a plantation in locality Jasika, Serbia. Morphological characterization identified Fusarium oxysporum f. sp. narcissi as the causal agent of bulb rot in daffodil. Three selected isolates were tested for their ability to produce symptoms on daffodil bulbs. Two weeks after artificial inoculation typical symptoms of basal rot developed on inoculated bulbs from which the pathogen was re-isolated fulfilling Koch’s postulates. To further identify the pathogen, a molecular characterization with sequence and phylogenetic analysis of ITS and TEF1 genomic regions was performed. Molecular characterization confirmed the obtained results in morphological identification. The detection of Fusarium oxysporum f. sp. narcissi, a causal agent of basal rot on daffodil in Serbia, is the first report of this pathogen in the country.

U radu je ispitivano na koji način kišna glista Lumbricus rubellus svojom aktivnošću utječe na brojnost različitih fizioloških grupa mikroorganizama u zemljištu tretiranim pesticidom Stomp 330 E čija je aktivna supstanca pendimetalin. Eksperiment je postavljen u 10 staklenih kontejnera sa zemljišnim supstratom, pri čemu je jedan kontejner bio kontrolni, a po tri kontejnera su tretirana s tri različite koncentracije pendimentalina. Korištena je deklaracijom preporučena koncentracija pesticida od 5 μl/kg, jedna niža koncentracija od 3 μl/kg i jedna viša koncentracija od 7 μl/kg. Brojnost fizioloških grupa mikroorganizama je određena iz tri komore tretirane različitim koncentracijama pendimetalina 48 sati nakon tretmana, a iz druge tri komore 21 dan nakon tretmana. Kako bi se utvrdilo postoji li interakcija između aktivnosti kišnih glista i brojnosti mikroorganizama u zemljištu kontaminiranom pesticidom u tri komore je pored navedenih koncentracija pesticida ubačeno po 10 odraslih jedinki vrste Lumbricus rubellus. Mikrobiološka analiza supstrata je izvršena 21 dan nakon tretmana. Utvrđeno je da je dva dana nakon primjene različitih koncentracija pesticida došlo do statistički značajnog opadanja brojnosti gljivica i celulolitičkih mikroorganizama u zemljištu, dok se brojnost ukupnih heterotrofnih bakterija, kao i mikroorganizama koji sudjeluju u različitim etapama metabolizma dušika višestruko povećala. Međutim, 21 dan nakon provođenja tretmana zabilježen je značajan pad brojnosti ukupnih heterotrofnih bakterija u svim tretiranim kontejnerima u odnosu na kontrolni, pri čemu su kišne gliste svojom aktivnošću djelomično ublažile negativan efekt pendimentalina na ukupnu zemljišnu bakteriofloru te su pozitivno djelovale na brojnost gljivica, aktinomiceta i celulolitičkih mikroorganizama, dok na brojnost aminoautotrofa, oligonitrofila i slobodnih dušičnih fiksatora prisustvo kišnih glista u zemljištu nije imalo značajan utjecaj. Pokazalo se da kišne gliste svojom aktivnošću ublažavaju negativno djelovanje pesticida Stomp 330 E na bakteriofloru i gljivice, čime se ističe njihova moguća upotreba u procesima bioremedijacije., This paper examines the modus in which earthworm Lumbricus rubellus with its activity affects the total count of different physiological groups of microorganisms in soil treated with herbicide pendimethalin. The experiment was carried out in ten glass containers with a soil substrate, whereby one of them was the control one, and each group of three containers was treated with different concentration of pendimethalin. A concentration of pesticide of 5 μl/kg, which is recommended by the declaration, one lower concentration of 3 μl/kg and one higher of 7 μl/kg were used. The number of physiological groups of microorganisms is determined from the three containers treated with different concentrations of pendimethalin 48 hours after the treatment, and from the other three containers 21 days after the treatment. Two days after the application of different concentration of pesticide, a significant statistical decrease was found in the number of fungi and cellulotical microorganisms in soil, while the total number of heterotrophic bacteria as well as microorganisms which participate in different stages of nitrogen metabolism increased. However, 21 days after the treatment a significant decrease in the total number of heterotrophic bacteria in all treated containers comparing to the control one was noticed, where earthworms with their activities partially attenuated the negative effect of pendimethalin on soil bacterial flora. They also had a positive effect on the number of fungi, actinomycetes and cellulolytic microorganisms while the presence of earthworms had no significant influence on the number of aminoautotrophs, oligonitrophils and free-living diazotrophs. It was shown that earthworms with their activities attenuate the negative effect of pendimethalin on bacterial flora, actinomycetes and fungi, which points out to their possible use in processes of bioremediation.

During a survey from 2004 to 2016, symptoms of grapevine dieback were observed in six vineyards in Serbia. Symptoms initially appeared as small, chlorotic, and necrotic spots along the rim of the leaves, deformation of leafs, and the appearance of shortened shoots, often with the so-called zigzag internodes. Over time, partial or complete dying of the vines developed. Symptomatic samples were collected and submitted to laboratory analysis. Based on the morphological characterization, the isolated fungus was initially identified as belonging to Eutypa species. Pathogenicity tests showed that 47 selected isolates caused tissue necrosis around the site of inoculation, chlorosis, and deformation of the leaves, along with the appearance of tiny, necrotic spots on the periphery of the leaf that fall off over time. Inoculated cuttings were stunted, dwarf-like with zigzag internodes. Molecular identification was done with sequence and phylogenetic analysis of ITS, TUB, and RPB2 genomic regions. Based on the phylogenetic analysis, all isolated fungi were determined as Eutypa lata.

The object of this study was a two-year trial (2009 and 2010) regarding variability of morphological characteristics of species belonging to Sorghum genus, more specifically interspecies hybrid between sorghum and Sudan grass Siloking as affected by different applications of nitrogen. The following morphological characteristics were analysed: plant height, number of leaves, leaf ratio, stem ratio, and number of shoots. Samples were taken from the first cut when the effect of the applied nitrogen doses was the strongest. The results showed that increasing nitrogen quantities significantly affected the tested morphological characteristics, especially the intensity of tillering (increased number of secondary stems), number of the formed leaves, and ratio of leaf weight in the total above-ground biomass. The effect of applied nitrogen depended on the weather conditions, i.e. distribution of precipitation, so that plants reached maximum height when 105 kg N ha-1 was applied in the dry year and 180 kg N ha-1 in the wet year. Predmet ove studije su dvogodišnja istraživanja (2009. i 2010.) varijabilnosti morfoloških osobina vrste roda Sorghum interspecies hibrida sirka i sudanske trave Siloking zavisno od upotrebljenih količina azota. Analizirane su morfološke osobine: visina biljka, broj listova, udeo lista, udeo stabla, broj izdanaka, a uzorci su uzimani iz prvog otkosa kada je i efekat upotrebljenih azotnih hraniva bio najveći. Rezultati su pokazali da rastuće količine azota značajno utiču na ispitivane morfološke osobine posebno na intenzitet bokorenja (povećanje broja sekundarnih stabala), broj formiranih listova, kao i udeo lisne mase u ukupnoj nadzemnoj biomasi. Efekat upotrebljenog azota zavisio je od vremenskih uslova, odnosno od rasporeda padavina, te su biljke dostigle najveću visinu u varijanti sa primenjenih 105 kg ha-1 azota u sušnoj, a u varijanti sa 180 kg ha-1 u vlažnoj godini.

Genetic-physiological approach was used in the study of the quality of Serbian spruce seed (Picea omorika /Pancic/Purkynĕ), collected in the populations on the left bank of the river Drina. The seed originated from the three populations that represent the overall ecological and productive conditions of Serbian spruce populations in Bosnia and Herzegovina. Two natural populations were selected: Veliki Stolac and Gostilj, and one planted forest population in Srebrenica. The cones were collected in late autumn 2009 and early spring 2010. They were collected from five trees from Srebrenica and Gostilj, and seven trees from Veliki Stolac. Immediately after they were collected, the cones and seeds were processed and germination tests were done. Germination, germination viability and germination dynamics were studied in three categories of seed treatment: 1) control unit (just processed seed), 2) seed stored for six months at 0-4 oC, 3) seed stored for seven months at 0-4o C and treated with fungicide after five months of storing. The number of germinated seed was observed and noted on the third, fourth, fifth, seventh, tenth, fourteenth, twenty-first and twenty-eighth day. There were significant differences in germination dynamics at the population level and the level of treatment during the first couple of days of germination test. Fungicide (captan) acted as an inhibitor on seed germination process. The seeds originating from the largest population of Veliki Stolac showed the best response to storing treatment with fungicide related to germination dynamics. The seed originating from Srebrenica andkept at low temperatures 0-4 °C without treatment with fungicides showed the best result in germination. Regardless of the presence of differences in the dynamics of germination, significant differences in germination regarding different treatments on the last day of the test, were not recorded.

Colletotrichum trifolii is a fungal pathogen responsible for anthracnose disease in alfalfa. The isolates of C. trifolii were obtained from diseased alfalfa stems collected from field in Serbia. It was determined by pathogenicity examination that four isolates (Luc-7, Luc-17, Luc-27, Luc-33) can cause stem lesions on inoculated alfalfa plant. Our isolates were compared using reference isolates of C. trifolii (CBS 158.83). Isolates on MA and CDA developed olive green to grey colonies with white margin, while the substrate got dark olive green color. Conidiophores were hyaline, varied in length and produced a succession of conidia apically. Conidia were hyaline, straight, rounded at the ends, and non-septated with average size 7.85x3.87 μm. Average sizes of appressoria were 7.5-16.5 x 5.5 x 8.9 μm. The polymerase chain reaction (PCR) with one set of specific primers was used for the detection of examined isolates of Colletotrichum trifolii. Amplification of desired DNA fragment (590 bp) was determined using specific primer pair TB3-F/TB3-R. Achieved results of amplification indicated that the isolates Luc-7, Luc-17, Luc-27, as well as CBS 158.83, had traits of C. trifolli. Amplification and band on about 430 bp appeared in isolate Luc-33, which also belonged to C. trifolli species.

During summer and autumn, easily recognizable diseased plants can be detected in alfalfa fields. Diseased plants have characteristically curved apical part, commonly known as 'shepard's hook'. Using the standard mycological methods, several fungi isolates were obtained. Four of these isolates were used for further study. Two standard mycological methods were used for determination of pathogenicity of Colletotrichum spp. isolates: with and without damaging of the stems. During these studies, it was determined that all of the isolates were causing the symptoms of alfalfa anthracnose. All of the selected isolates form germinative bodies - acervulae - on mycelium. Acervulae can be grouped or scattered across the colony area. Their size in the culture was 100-250 mm. Conidia were short, cylindrical, relatively broad, with both end obtuse 7,85 x 3,85 mm. Appressoria were ovate to obovoid, pale to medium brown 7,5-16,5 x 5,5-8,9 ?m.