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Acidovorax citrulli, the causal agent of bacterial fruit blotch (BFB), is an economically important pathogen of watermelon and related plant species worldwide. In the period 2014–2018, several outbreaks of BFB were observed in major watermelon production regions in Serbia. A total of 43 strains, isolated from symptomatic watermelon tissue, were analyzed by biochemical, pathogenic and molecular tests. Based on the phenotypic characteristics, PCR assay, and 16S rRNA gene sequence analysis, all strains were identified as A. citrulli. A multilocus sequence analysis of the four housekeeping (adk, gyrB, pilT and gltA) and three virulence genes (Aave_1548, avrRx01 and luxR) revealed that studied A. citrulli strains represent the homogeneous population and they clustered together with group II reference strain AAC00-1. Strain affiliation to group II was confirmed by PCR based on the putative type III secretion effector gene and by duplex PCR test. High homogeneity of studied strains was also confirmed by BOX-PCR. Differences were observed for two strains in their pathogenicity as well as susceptibility to copper compounds. Moreover, six major watermelon varieties grown in Serbia showed high sensitivity to the pathogen, while cross inoculation assay revealed that the strains were able to infect other species within the Cucurbitaceae family.

Chitosan and its derivatives have been reported as a promising alternative for control of postharvest fungal pathogens. The objective of this study was to evaluate in vitro and in situ antifungal activity of chitosan against Alternaria alternata and Colletotrichum gloeosporioides isolated from decayed apple fruits. The fungi were tested in vitro using PDA medium with three concentrations of chitosan (1, 2 and 3 mg/ml). Fungal growth of the test pathogens was significantly affected by all chitosan doses (P lt 0.05) after 7 days of incubation at 25°C. Water solution of 3 mg/ml of chitosan inhibited completely the conidial germination of A. alternata and C. gloeosporioides after 18 h incubation at 25°C. The results obtained from biocontrol assay indicate that the inhibition of postharvest decay of A. alternata and C. gloeosporioides was significantly influenced by chitosan concentrations. Disease incidence in chitosan-treated fruit after 7 days incubation at 25°C was significantly lower than in the positive control for both fungi tested (P lt 0.05). A. alternata and C. gloeosporioides used in this study were progressively inhibited in vitro and in situ with increasing concentrations of chitosan from 1 to 3 mg/ml., Istraživanja pokazuju da su hitosan i njegovi derivati dobra alternativa u kontroli skladišnih fitopatogenih gljiva. Cilj ovog rada bio je da ispita antifungalnu aktivnost hitosana prema Alternaria alternata i Colletotrichum gloeosporoides, izolovanih sa inficiranih plodova jabuke, u in vitro i in situ uslovima. Rast gljiva je testiran in vitro koristeći PDA podlogu sa različitim koncentracijama hitosana (1, 2 i 3 mg/ml). Porast oba patogena je bio značajno smanjen (P lt 0.05) u svim koncentracijama hitosana nakon 7 dana inkubacije na 25°C. Vodeni rastvor hitosana koncentracije 3 mg/ml je u potpunosti inhibirao klijanje konidija A. alternata i C. gloeosporoides nakon inkubacije od 18 sati na temperaturi od 25°C. Rezultati ogleda in situ ukazuju da inhibicija propadanja plodova inficiranih sa A. alternata i C. gloeosporoides zavisi od koncentracije rastvora hitosana. Pojava bolesti na plodovima jabuka tretiranih rastvorom hitosana nakon 7 dana inkubacije na 25°C bila je značajno smanjena za obe vrste gljiva (P lt 0.05) u odnosu na pozitivnu kontrolu. Rast A. alternata i C. gloeosporoides je bio progresivno inhibiran in vitro i in situ sa povećanjem koncentracije rastvora hitosana, od 1 do 3 mg/ml.

The control of Plasmopara viticola and Botrytis cinerea, two of the most dangerous pathogens on grapevine, requires frequent treatments with chemicals based on weather conditions. Numerous applications of fungicides have resulted in developing fungicide resistance. Active ingredients based on copper have been used very successfully for a long time to protect grapevines against these pathogens. Application of a copper citrate formulation with high degree dissociation at a very low concentration (1%) was evaluated in field trials. The efficacy of two concentrations of copper citrate, 0.5 and 1.0%, were tested against P. viticola on grapevine in three locations, and against B. cinerea in two locations during 2018. Our results demonstrated that the concentration of 1.0% copper citrate was highly effective against P. viticola (87.4%) and B. cinerea (63.7%), compared to standard treatment (90.6 and 53.1%), under a high level of infection., Zaštita vinove loze od prouzrokovača plamenjače vinove loze - Plasmopara viticola i sive truleži - Botrytis cinerea, je vrlo kompleksna i zahteva primenu većeg broja hemijskih tretmana, u skladu sa vremenskim uslovima. Učestala primena fungicida uslovljavala je pojavu rezistentnih izolata patogena na fungicide. Različite forme bakarnih jedinjenja primenjuju se u zaštiti vinove loze dugi niz godina prilično uspešno. Primena bakar-citrata - formulacije sa visokim stepenom disocijacije u niskoj koncentraciji (1,0%) ispitivana je u poljskim uslovima. Efikasnost dve koncentracije bakar-citrata - 0.5 i 1.0% je testirana u suzbijanju P. viticola i B. cinerea na vinovoj lozi na tri (dva) lokaliteta, tokom 2018 godine. Naši rezultati pokazuju da je ispitivana koncentracija od 1,0% bakar-citrata ispoljila zadovoljavajući efekat na P. viticola (87,4%) i B. cinerea (63,7%) u odnosu na primenjene standarde (90,6% i 53,1%) u uslovima visokih zaraza.

Tokom ispitivanja sprovedenog u periodu od 2013. do 2016. godine, pregledom pet komercijalno značajnijih sorti kupine na 24 lokaliteta u 13 okruga u Srbiji, ustanovljena je široka rasprostranjenost bolesti stabla kupine (incidenca 5 - 80%, prosečno 37,7%), a nekroza i pucanje kore bili su najčešći simptomi. U pojedinim lokalitetima zabeleženo je sušenje 40% biljaka uz direktno smanjenje prinosa od oko 50%. Rasvetljavanje etiologije bolesti stabla kupine u Srbiji obavljeno je kroz morfološku i molekularnu identifikaciju i karakterizaciju 468 izolata dobijenih iz 427 uzoraka. Nakon ispunjenja Kohovih postulata, na osnovu makroskopskih i mikroskopskih osobina dobijeni izolati izdvojeni su u 10 morfoloških grupa što je potvrđeno sekvenciranjem ITS regiona rDNA. Identifikovano je 10 vrsta gljiva prouzrokovača bolesti stabla kupine u Srbiji: Paraconiothyrium fuckelii, Gnomoniopsis idaeicola, Septoria spp., Botryosphaeria dothidea, Diplodia seriata, Botrytis cinerea, Colletotrichum kahawae, Diaporthe eres, Diaporthe betulae i Neofusicoccum parvum. Dodatna karakterizacija na osnovu filogenetskih analiza urađena je za vrste G. idaeicola, B. dothidea, D. seriata, C. kahawae, D. eres, D. betulae i N. parvum čime je određena njihova srodnost i međuodnos sa ostalim vrstama rodova Gnomoniopsis, Botryosphaeria, Diplodia, Colletotrichum, Diaporthe i Neofusicoccum. Izolate Septoria spp. moguće je bilo identifikovani do nivoa roda na osnovu morfoloških, patogenih i molekularnih odlika i biće predmet daljih istraživanja uz sekvenciranje dodatnih molekularnih markera. Tokom ovih istraživanja vrsta G. idaeicola prvi put je opisana na kupini u Srbiji, a kako se pokazalo da je rasprostranjena u skoro polovini ispitivanih zasada, to predstavlja i prvu masovnu pojavu na kupini u svetu kao i prvi uvid u moguću epidemiologiju nekroze stabla i sušenja kupine izazvane sa G. idaeicola. Izolati G. idaeicola iz Srbije ispoljili su morfološku, molekularnu i biološku varijabilnost što je ustanovljen, A Survey was conducted from 2013 to 2016 which included a total of 24 orchards planted with five of the most commonly grown blackberry cultivars in 13 administrative districts in Serbia. A wide distribution of blackberry cane diseases (incidence of 5 - 80%, with an average of 37,7%) was observed with the most frequent symptoms of bark necrosis and canker. In some of the localities, the wilting of up to 40% of plants was recorded with yield reduction of about 50%. The etiology of blackberry cane diseases was investigated through morphological and molecular identification and characterization of 468 isolates obtained from 427 samples. After fulfilling the Koch’s postulates, the isolates were grouped into 10 morphological groups based on macroscopic and microscopic features which were confirmed by the sequencing of the ITS region rDNA. Ten species of fungi causing blackberry cane diseases were identified including Paraconiothyrium fuckelii, Gnomoniopsis idaeicola, Septoria spp., Botryosphaeria dothidea, Diplodia seriata, Botrytis cinerea, Colletotrichum kahawae, Diaporthe eres, Diaporthe betulae and Neofusicoccum parvum. Additional characterization based on phylogenetic analysis was performed for G. idaeicola, B. dothidea, D. seriata, C. kahawae, D. eres, D. betulae and N. parvum and revealed their relationship to the additional species within the genera of Gnomoniopsis, Botryosphaeria, Diplodia, Colletotrichum, Diaporthe and Neofusicoccum. Isolates of Septoria spp. could be identified to the genus level based on morphological, pathogenic and molecular features and will be subjected to further research through sequencing of additional molecular markers. During this research G. idaeicola was detected on blackberries in Serbia for the first time. As it was found that G. idaeicola was distributed in almost half of the orchards, this is the first record of a massive outbreak of G. idaeicola on blackberries in the world as well as the first insight into the possible epidemi

Blackberry cane diseases with the symptoms of necrosis, canker, and wilting are caused by several fungi worldwide. Surveys conducted from 2013 to 2016 in Serbia revealed the occurrence of Gnomoniopsis idaeicola, the causal agent of cane canker and wilting, which was found to be distributed in almost half of the surveyed orchards, in three blackberry cultivars, and with disease incidence of up to 80%. Wide distribution and high disease incidence suggest that G. idaeicola has been present in Serbia for some time. Out of 427 samples, a total of 65 G. idaeicola isolates were obtained (isolation rate of 34.19%). Reference isolates, originating from different localities, were conventionally and molecularly identified and characterized. G. idaeicola was detected in single and mixed infections with fungi from genera Paraconiothyrium, Colletotrichum, Diaporthe, Botryosphaeria, Botrytis, Septoria, Neofusicoccum, and Discostroma, and no diagnostically specific symptoms could be related directly to the G. idaeicola infection. In orchards solely infected with G. idaeicola, blackberry plant mortality was up to 40%, and yield loses were estimated at 50%. G. idaeicola isolates included in this study demonstrated intraspecies diversity in morphological, biological, pathogenic, and molecular features, which indicates that population in Serbia may be of different origin. This is the first record of a massive outbreak of G. idaeicola infection, illustrating its capability of harmful influence on blackberry production. This study represents the initial step in studying G. idaeicola as a new blackberry pathogen in Serbia, aiming at developing efficient control measures.

In the morphological studies were included isolates of Colletotrichum spp. originating from pear, apple and sour cherry fruits, as well as reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97). The colony characteristics, appearance, shape and size of conidioma, appressoria, and conidia of isolates of Colletotrichum spp. were studied. The four morphological groups of colonies on PDA were observed, confirming the great phenotypic variability of isolates of Colletotrichum spp. Most isolates from apple and pear fruits (KC-6, KC-9, KC-12, JC-5, JC-7, JC-9), formed the first morphological group. The isolates from sour cherry (VC-3, VC-5, VC-7, VC-9) are separated in the fourth morphological group. The size and shape of conidia from these isolates fit the description of C. gloe­osporioides. The chromogenic isolates from pear (KC-21, KC-23, KC-82) formed the second morphological group, and in the third morphological group is isolate (JC-4) from apple fruit. The morphology of conidia from these isolates fit the description of C. acutatum. During this research were evident that all isolates formed conidioma - acervuli. The tested cultures of Colletotrichum spp. did not form teleomorpf. Because of outstanding variability, most of the studied characteristics cannot be independently applied as taxonomic criteria. Obtai­ned results showed that, for Colletotrichum species classification, at least two taxonomic criteria should be used: morphological features combined with molecular identification., U morfološka ispitivanja su uključeni izolati Colletotrichum spp. poreklom sa plodova kruške, jabuke i višnje, kao i referentni sojevi C. acutatum (CBS 294.67) i C. gloeosporioides (CBS 516.97). Proučavanjem njihovih morfoloških karakteristika, dobijeni su podaci o izgledu ispitivanih kolonija, odlikama plodonosnog tela, apresorija, veličini i obliku konidija. Na podlozi KDA moguće je razlikovati četiri morfološke grupe kolonija, što potvrđu­je fenotipsku varijabilnost proučavanih izolata Colletotrichum spp. Većina izolata sa ploda kruške i jabuke (KC-6, KC-9, KC-12, JC-5, JC-7, JC-9) obrazuje prvu morfološku grupu. Izolati sa ploda višnje (VC-3, VC-5, VC-7, VC-9), su izdvojeni u četvrtu morfološku grupu. Veličina i oblik konidija ovih izolata odgovara opisu vrste C. gloeosporioides. Hromogeni izolati sa kruške (KC-21, KC-23, KC-82), obrazuju drugu morfološku grupu, a u trećoj morfološkoj grupi je izolat sa ploda jabuke (JC-4). Morfologija konidija ovih izolata odgovara opisu vrste C. acutatum. Tokom ovih istraživanja je utvrđeno da svi izolati obrazuju plodonosna tela - acervule. Testirane kulture Colletotrichum spp. ne formiraju teleomorfni stadijum. Zbog izražene varijabilnosti, većina ispitanih osobina ne mogu se primeni kao samostalni taksonomski kriterijum. Na osnovu dobijenih rezultata, za klasifikaciju vrsta roda Colletotrichum, potrebno je koristiti najmanje dva taksonomska kriterijuma: morfološke karakteristike uporedo sa molekularnom identifikacijom.

The pathogenic characteristics of 20 isolates of Colletotrichum spp. originating from pear, apple, sour cherry and tomato fruits, as well as reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97) are presented in this paper. In the studies of host range of isolates of Colletotrichum spp. were included 17 plant species. Nine days after artificial inoculation all tested isolates were caused anthracnose lesion on fruits of apple, pear, peach, apricot, sour cherry, sweet cherry, plum, strawberry, grape, tomato, pepper, eggplant, cucumber, zucchini, and green beans. Isolates of Colletotrichum spp. originating from the same host showed some differences in the degree of aggressiveness, which can be interpreted as the genetic variability of populations. The results of one-way analysis of variance indicate that the pathogenicity of isolates of Colletotrichum spp. is statistically significantly different on immature and mature fruits of pear, apple, sour cherry and tomato. Low to moderate sensitivity of immature fruits was confirmed by comparison of the degree of necrosis. Mature fruits were manifested a strong sensitivity to all tested isolates of Colletotrichum spp., U radu su prikazane patogene karakteristike 20 izolata Colletotrichum spp. poreklom sa plodova kruške, jabuke, višnje i paradajza, kao i referentnih sojeva C. acutatum (CBS 294.67) i C. gloeosporioides (CBS 516.97). U proučavanja kruga domaćina izolata Colletotrichum spp. uključeno je 17 biljnih vrsta. Devet dana nakon veštačkih inokulacija svi testirani izolati prouzrokovali su antraknozne lezije na plodu jabuke, kruške, kajsije, trešnje, višnje, šljive, jagode, grožđa, paradajza, paprike, plavog patlidžana, krastavca, tikvice i boranije. Izolati Colletotrichum spp. poreklom sa istog domaćina pokazuju izvesne razlike u stepenu agresivnosti, što se može tumačiti genetskom varijabilnošću populacija. Rezultati jednofaktorijalne analize varijanse ukazuju na statistički značajne razlike u patogenosti izolata Colletotrichum spp. na nezrelim i zrelim plodovima kruške, jabuke, višnje i paradajza. Poređenjem stepena nekroze utvrđena je slaba do umerena osetljivost nezrelih plodova. Zreli plodovi su manifestovali jaku osetljivost prema svim testiranim izolatima Colletotrichum spp.

Isolates of Colletotrichum spp. obtained from nectarine fruits with typical anthracnose symptoms in 2010 were identified using morphological and molecular methods. Pathogenicity test was conducted on symptomless, detached nectarine fruits. All tested isolates caused anthracnose lesions on nectarine fruits after 7 days of incubation. On PDA medium nectarine isolates forming dark green to dark gray mycelia. Growth rates of all isolates and reference strain of C.acutatum were lower at 25°C compared with reference strain of C.gloeosporioides. The conidia were hyaline, aseptate, and fusiform. Appressoria were dark brown, smooth, simple, and clavate to ovate. Using the primer set CaInt2/ITS4, the 490 bp DNA fragment was amplified from all nectarine isolates and reference strain of C. acutatum - CBS 294.67. Based on these results, the causal agent of anthracnose on nectarine fruits in Serbia was identified as C.acutatum., Izolati Colletotrichum spp. dobijeni 2010. godine, sa antraknoznih plodova nektarine identifikovani su pomoću morfoloških i molekularnih metoda. Test patogenosti je obavljen sa reprezentativnim izolatima, na odabranim, zdravim plodovima. Svi ispitivani izolati prouzrokuju antraknozne lezije na plodu nektarine, 7 dana nakon inokulacije. Na PDA podlozi izolati formiraju tamno zelenu do tamno sivu miceliju. Stopa rasta izolata sa nektarine i referentnog soja C.acutatum je bila niža u odnosu na referentni soj C.gloeosporioides. Konidije su hialinske, neseptirane i fusiformne. Apresorije su tamno braon boje, glatke, jednostavne, okruglastog ili oblika izdužene palice. Korišćenjem para prajmera CaInt2/ITS4 iz genoma DNA izolata sa ploda nektarine i referentnog soja C. acutatum - CBS 294.67, amplifikovan je fragment veličine 490 bp. Na osnovu ovih rezultata, u Srbiji je kao prouzrokovač antrakoze plodova nektarine identifikovana vrsta C.acutatum.

In the physiological studies were included 20 isolates of Colletotrichum spp. originating from pear, apple, sour cherry and tomato fruits, as well as reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97). The results indicated that five different culture media (PDA, CA, OA, MEA, CDA), seven different pH (3, 4, 5, 6, 7, 8, 9), and temperatures (5º, 10º, 15º, 20º, 25º, 30º, 35ºC) have significant influence on growth and sporulation of isolates of Colletotrichum spp. All tested media, except CDA, were suitable for pathogens development. Five morphological groups of colonies on PDA were observed, confirming the great phenotypic variability of isolates. The best media pH for pathogens growth and sporulation were pH 6 and 7. The optimum temperature for colonies development was 25˚C, and temperatures of 20° and 25ºC were the most favorable for sporulation of isolates of Colletotrichum spp., U fiziološka ispitivanja su uključena 20 izolata Colletotrichum spp. poreklom sa plodova kruške, jabuke, višnje i paradajza, kao i referentni sojevi C. acutatum (CBS 294.67) i C. gloeosporioides (CBS 516.97). Rezultati ukazuju da pet različitih hranljivih podloga (PDA, CA, OA, MEA, CDA) sedam različitih pH (3, 4, 5, 6, 7, 8, 9) i temperatura (5º, 10º, 15º, 20º, 25º, 30º, 35ºC) imaju značajan uticaj na razvoj i sporulaciju izolata Colletotrichum spp. Sve testirane podloge, izuzev CDA su pogodne za razvoj patogena. Na podlozi PDA moguće je razlikovati pet morfoloških grupa kolonija, što potvrđuje fenotipsku varijabilnost proučavanih kultura. Podloge pH 6 i 7 su najbolje za porast i sporulaciju patogena. Optimalna temperatura za razvoj ispitivanih kolonija je 25°C, a temperature od 20° i 25°C su najpovoljnije za sporulaciju izolata Colletotrichum spp.

In Serbia, the occurrence of anthracnose on pear, apple, sour cherry, and tomato fruits has been recorded during the last several years. Colletotrichum spp. were isolated from all diseased fruits. Twenty monoconidial isolates were selected for comparative studies, and the reference strains of C. acutatum (CBS 294.67) and C. gloeosporioides (CBS 516.97) were used as a control. The physiological studies have included the investigation of the effect of different sources of carbon and nitrogen on growth of C. acutatum and C. gloeosporioides. The results indicated that carboxymethyl cellulose was the most appropriate source of carbon for the growth of isolates of Colletottrichum spp. Of the three nitrogen sources studied, the best growth of all tested fungi was recorded on the media with casein hydrolysate., U Srbiji je tokom poslednjih godina zabeležena pojava antraknoze ploda kruške, jabuke, višnje i paradajza. Iz obolelih plodova su izolovane gljive roda Colletotrichum. Za komparativna istraživanja je odabrano 20 monosporijalnih izolata, kao i referentni sojevi C. acutatum (CBS 294.67) i C. gloeosporioides (CBS 516.97) koji su predstavljali kontrolu. Fiziološka proučavanja su obuhvatila i određivanja uticaja različitih izvora ugljenika i azota na porast kultura C. acutatum i C. gloeosporioides. Rezultati su pokazali da je karboksimetilceluloza najadekvatniji izvor ugljenika za rast izolata Colletottrichum spp. Od tri proučavana izvora azota, najveći porast svih testiranih gljiva zabeležen je na podlogama sa kazeinhidrolizatom.

Colletotrichum gloeosporioides, Colletotrichum acutatum, Colletotrichum coccodes, and Colletotrichum dematium are the four main species of Colletotrichum that cause tomato anthracnose. In Serbia, the occurrence of anthracnose on tomato fruit has been recorded during the last several years. Typical fruit symptoms include dark, sunken, and circular lesion with orange conidial masses. Pathogen isolates were obtained from a diseased tomato fruits, on PDA medium forming a white to gray colonies. The cultures developed black acervuli around the center of the colony. Conidia were hyaline, aseptate, and fusiform or rarely cylindrical. Appressoria were smooth, simple, clavate to ovate, and varied from light to dark brown. Pathogenicity tests with representative isolates were conducted on symptomless, detached tomato fruits. All tested isolates caused anthracnose lesions on tomato fruit after 7 days of incubation. Koch's postulates were fulfilled by reisolation from inoculated tomato fruits. PCR analysis (using species-specific primer pair, CaInt2/ ITS4) of genomic DNA from tomato isolates resulted in an amplification product of 490 bp, specific for C. acutatum, further confirming the identity of the pathogen. Based on morphological and molecular characteristics, the isolates from tomato fruit were determined as C. acutatum., Četiri glavna prouzrokovača antraknoze paradajza iz roda Colletotrichum su: Colletotrichum gloeosporioides, Colletotrichum acutatum, Colletotrichum coccodes i Colletotrichum dematium. U Srbiji je tokom poslednjih godina zabeležena pojava antraknoze ploda paradajza. Tipični simptomi na plodu su tamne, ulegnute, kružne lezije sa masom narandžastih konidija. Sa obolelih plodova paradajza dobijeni su izolati patogena koji na KDA podlozi obrazuju bele do sivo obojene kolonije. Acervuli crne boje formiraju se u kulturi oko centra kolonije. Konidije su hialinske, neseptirane, fusiformne ili ređe cilindrične. Apresorije su glatke, jednostavne, okruglastog ili oblika izdužene palice, svetlo do tamno braon boje. Test patogenosti je obavljen sa reprezentativnim izolatima, na odabranim, zdravim plodovima. Svi ispitivani izolati prouzrokuju antraknozne lezije na plodu paradajza 7 dana nakon inokulacije. Kohovi postulati su zadovoljeni reizolacijama sa inokulisanih plodova paradajza. PCR analiza (korišćenjem para prajmera specifičinog za vrstu, CaInt2/ITS4) iz genoma DNA izolata sa paradajza rezultirala je amplifikacijom produkta od 490 bp, specifičnog za C. acutatum, što je potvrdilo identitet patogena. Na osnovu morfoloških i molekularnih karakteristika izolati sa ploda paradajza determinisani su kao C. acutatum.

The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest antagonism against isolates of C. acutatum and C. gloeosporioides. Microscopic examination showed that the most common mode of action was antibiosis. The results of this study identify T. harzianum, G. roseum, B. subtilis, S. natalensis and S. noursei as promising biological control agents for further testing against anthracnose disease in fruits., Antagonističko delovanje pet agenasa biološke zaštite: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei i Streptomyces natalensis, testirano je in vitro na Colletotrichum acutatum i Colletotrichum gloeosporioides, prouzrokovače antraknoze plodova. Svi mikrobni antagonisti inhibiraju porast micelije u testovima dvojne kultivacije i klijavost konidija Colletotrichum izolata. Dve vrste roda Streptomyces ispoljavaju najjači stepen antagonizma prema izolatima C. acutatum i C. gloeosporioides. Mikroskopsko ispitivanje pokazuje da je antibioza najčešći način delovanja antagonista. T. harzianum, G. roseum, B. subtilis, S. natalensis i S. noursei su rezultatima ovih istraživanja identifikovani kao biološki agensi koji se mogu uspešno uključiti u buduća testiranja u cilju suzbijanja antraknoze plodova.

The effects of copper citrate on defoliation of one year old fruit stocks in a nursery are presented in this paper. The investigation aimed to evaluate the defoliation efficacy of copper citrate as a new formulation, compared with other compounds recommended for that purpose. Field trials were conducted in the region of Trstenik, a center of nursery production in Serbia in 2016 and 2017. Two years of investigation showed that copper citrate could be used as an efficient compound for defoliation in nursery production. A stronger defoliation effect was observed on plum stocks, compared to apple stocks. Better results were achieved with the highest concentration of copper citrate (2%), while the effectiveness decreased with lower concentrations (0.5%, 1.0% and 1.5%). Defoliation degree on nursery apple stocks after treatment with 2.0% concentration of copper citrate varied from 80.6% to 95.6%, while it reached 100% on plum stocks., U radu su prikazani efekti defolijacije sadnica jabuke i šljive, primenom različitih koncentarcija bakar citrata, kao nove formulacije, i standardnih preparata koji se koriste u ove svrhe (bordovska čorba, urea). Ogledi su sprovedeni u regionu Trstenika (Ljubava i Milutovac), koji je centar rasadničke proizvodnje u Srbiji. Tretiranja su obavljena tokom 2016. i 2017. godine. Na osnovu dobijenih rezultata zaključeno je da bakar citrat pokazuje visok potencijal za upotrebu u svrhu defolijacije sadnica jabuke i šljive. Korišćene koncentracije ovog jedinjenja su pokazale veću efikasnost u primeni na sadnicama šljive nego na sadnicama jabuke. Najbolji rezultati u oba ogleda su zabeleženi sa maksimalno primenjenom koncentracijom (2%), dok efekat defolijacije na sadnicama jabuke opada sa smanjenjem koncentracije. Stepen defolijacije jabuke primenom bakar citrata u koncentraciji od 2% kretao se od 80,6% do 95,6%, a kod šljive čak 100%. Potvrđeno je i da uspešna defolijacija sadnica jabuke i šljive značajno zavisi od vremena aplikacije kao i meteoroloških uslova.

Isolates of Phomopsis spp. obtained from plum trees (Prunus domestica L.) with symptoms of die-back. There were significant morpho-physiological and pathogenic differences between the isolates. The genetic variability (12 isolates of Phomopsis spp. and isolate of Photopia pernicious, which was used as control ) was proved by study of vegetative compatibility. These isolates were inoculated in Petri dishes in pairs in all possible cross combinations, on potato dextrose agar. After 5 and 10 days the interaction between colonies were scored according to appearance of contact lines of paired cultures. On the contact line on two different isolates distinct barrage zones of inhibition - vegetative incompatibility reaction. The barrage zones generally became black and sometimes showed formation of pycnidia. Necrotic parts of hyphen that formed line of reaction were observed. A compatible reaction was observed only when cultures of the same isolate were paired., Izolati Phomopsis spp. dobijeni sa grana i stabla šljive (Prunus domestica L.) sa simptomima sušenja i izumiranja ispoljili su značajne razlike u morfolo-fiziološkim i patogenim karakteristikama. Primenom metode vegetativne kompatibilnosti potvrđena je genetska varijabilnost 12 izolata Phomopsis spp. i kontrolnog izolata Phomopsis perniciosa. Isečci ispitivanih kultura zasejavani su u Petri kutije po parovima i u svim mogućim unakrsnim kombinacijama, na podlozi KGA. Očitavanje rezultata je vršeno petog i desetog dana i podrazumevalo je praćenje izgleda linije međusobnog kontakta uparivanih izolata. Nakon perioda inkubacije između ispitivanih kultura dolazi do formiranja crne reakcione linije - barijere, a u pojedinim slučajevima i reproduktivnih organa - piknida (reakcija vegetativne inkompatibilnosti). Delovi hifa koje sačinjavaju crnu reakcionu liniju bili su nekrotirani. Vegetativna kompatibilnost konstatovana je samo u slučajevima kada su izolati uparivani sami sa sobom.

Twelve isolates of Phomopsis sp. were obtained from the branches and the trunk of plums (Prunus domestica L) with decay symptoms in Valjevo, Ljig Koceljeva and Ub vicinity during 2004-2006. Morphological, pathogenic and growing characteristics were studied. Pathogen caused tissue necrosis of branches around the inoculate seats, and wrinkling and watering of plum fruits. All media were suitable for pathogen development, except prune agar. The best growth of isolates was at medium pH 5,5. The optimal temperature for growth and germination of pycnidiospores was 25°C., Dvanaest izolata Phomopsis sp. dobijeno je sa grana i stabla šljive (Prunus domestica L) sa simptomima propadanja u okolini Valjeva, Ljiga, Koceljeve i Uba tokom 2004-2006. godine. Proučene su morfološke, patogene i odgajivačke odlike ovih izolata. Prvi simptomi uočavaju se u vreme cvetanja i listanja šljive ukoliko se infekcija desila u blizini pupoljaka i osnove lisnih peteljki. U tom slučaju listovi su sitniji i hlorotični. Kasnije i listovi i cvetovi nekrotiraju i suše se. Tek formirani mladi izdanci oboljevaju postaju nekrotični i propadaju. Na granama i stablu formiraju se ulegnute nekrotične pege, koje se brzo šire i u okviru kojih kora uzdužno puca, tako da se formiraju rak-rane. Nekroza se širi na drvenasti deo, gde bivaju zahvaćeni sprovodni sudovi, što dovodi do uvenuća i izumiranja grana. Patogen se dobro razvija na svim podlogama, osim na podlozi od suvih šljiva. Podloge čija je pH 5,5 pokazale su se kao najbolje za porast patogena. Temperature od 25°C su najpovoljnije za razvoj patogena i klijavost konidija.