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Posljednjih nekoliko godina, virusne bolesti tikvica i tikvi u Hrvatskoj javljaju se u sve jačem intenzitetu i uzrokuju gubitke u proizvodnji. Cilj rada bio je utvrditi prisutnost virusa mozaika krastavca (CMV), virusa žutog mozaika tikvice (ZYMV) i virusa mozaika lubenice (WMV) na tim kulturama. Tijekom 2019. godine, na 18 lokacija (polja na otvorenom) u šest županija provedeni su vizualni pregledi te je ukupno sakupljeno 43 simptomatičnih uzorka tikvice i 39 uzoraka tikve u svrhu laboratorijske analize na prisutnost CMV, ZYMV i WMV. Analiza je provedena imunoenzimskim testom DAS-ELISA korištenjem komercijalnih seroloških kompleta. Od 82 uzorka, CMV je potvrđen u njih 55 (67%), ZYMV u 50 (61%), a WMV u 10 uzoraka (12%). Pojedinačna zaraza s jednim od tri istraživana virusa utvrđena je u ukupno 38 uzoraka (46%). Mješovite zaraze s dva virusa zabilježene su u 36 uzoraka (44%): 32 uzorka (39%) s kombinacijom CMV + ZYMV te četiri uzorka (5%) s kombinacijom CMV + WMV. Mješovita zaraza sa sva tri virusa (CMV + ZYMV + WMV) utvrđena je u dva uzorka. U šest uzoraka (7%) nije zabilježen niti jedan od tri istraživana virusa. U osam nasada utvrđena je prisutnost jednog virusa, u devet nasada prisutnost dva virusa, a u jednom od 18 pregledanih nasada utvrđena je prisutnost sva tri istraživana virusa., Viral diseases of zucchini and pumpkin have become more severe in recent years, causing significant yield losses. The objective of this study was to determine the presence of cucumber mosaic virus (CMV), zucchini yellow mosaic virus (ZYMV) and watermelon mosaic virus (WMV) in these crops. In 2019, a survey was conducted at 18 sites (open fields) in six counties. Fortythree symptomatic samples of zucchini and 39 symptomatic samples of pumpkin were collected and tested for the presence of CMV, ZYMV and WMV. Samples were tested with commercial serological assays, using doubleantibody sandwich ELISA kits. Out of 82 samples analysed, CMV was detected in 55 (67%), ZYMV in 50 (61%), and WMV in 10 samples (12%). Single viral infection was detected in 38 samples (46%). Mixed infections with two viruses were recorded in 36 samples (44%), CMV + ZYMV combination in 32 samples (39%), and CMV + WMV combination in four samples (5%). Triple viral infection was detected in two samples, while six samples (7%) were determined to be free of all three viruses in the testes. One virus species was recorded at eight locations, two viruses at nine locations, while all three viruses were determined in one out of 18 sampled fields.

In May 2021, a tomato producer reported an occurrence of a disease unknown so far in a greenhouse near Split, Croatia. About 30% of plants (cultivar Signora) have been affected. Symptoms resembled tomato pith necrosis, bacterial disease caused by Pseudomonas corrugata, known to occur sporadically in tomato greenhouse production in Croatia. Leaves on plants developed interveinal chlorosis, followed by necrosis and leaf collapse. When main stems were longitudinally cut, brown, disintegrated and water-soaked partly hollow pith was evident. Severely affected plants wilted. With suspicion on presence of P. corrugata, bacteria were isolated from surface-sterilized pith tissue of two tomato plants by plating onto sucrose peptone agar (SPA) and King’s B medium (KB). Colonies recovered were cream-colored on SPA and non-florescent on KB. Two isolates, assigned as 1-KB and 3A, were first identified by amplification of internal transcribed spacer (ITS1) between16S rRNA and 23S rRNA using primers D21 and D22 (Manceau and Horvais 1997). The 550-bp PCR products obtained were purified and sequenced. Subsequent BLAST search showed the sequences to have 100% identity with the strain DSM 16733 isolated from tomato in Italy (Accession No. LT629790.1) and 99.77% identity with the strain SM664-12 isolated from tomato in USA (Acc. No. KC405207.1) of Pseudomonas mediterranea from NCBI. ITS sequence for one isolate 3A was deposited in GenBank under the Accession No. OP765279.1. Further identification was performed by using species-specific primers PC1/1-PC1/2 for P. mediterranea (Catara et al. 2000, 2002). Amplification of 600 bp DNA fragment confirmed the identity of isolates 1-KB and 3A as P. mediterranea. For this region sequence of isolate 3A was deposited in GenBank under the Acc. No. OP068273.1. Pathogenicity was assessed on tomato plants (cultivar Moneymaker) grown in pots in bio-chamber. Plants were grown at 25/20 °C 12h/12h dark/light regime until 8-leaves stage (BBCH 18). P. mediterranea isolate 3A was used for the inoculation. Inoculum was prepared from the isolate grown on KB medium for 48 h and suspended in sterile distilled water (concentration of 109 CFU mL-1) by dilution plate counts. Ten plants were inoculated with 10 µl of bacterial suspension injected into the stem with a syringe. Five control plants were inoculated with sterile distilled water. After 40 days of plant growth, symptoms were visible on all plants inoculated with P. mediterranea isolate 3A. Although no wilting was observed and all plants were alive, chlorosis was observed on upper leaves, chlorosis and necrosis on middle leaves, while basal leaves wilted. Longitudinal cross-sections of stems revealed brownish pith tissue with longitudinal watery pits spreading from inoculation points (Fig.S1). Symptoms were not observed on control plants. Bacterium was reisolated from three plants showing the most severe symptoms and proved to be identical to the original using species-specific primer pair PC1/1-PC1/2. To our knowledge, this is the first confirmation of P. mediterranea causing tomato pith necrosis in Croatia. Tomato pith necrosis caused by P. mediterranea may become significant bacterial disease of greenhouse tomato in Croatia.

Croatian isolates of Monilinia fructicola, M. laxa and M. fructigena have been collected from peach, nectarine, sweet cherry, plum and apricot fruits and assessed for their sensitivity to thiophanate-methyl. Out of 66 isolates collected, 34 were identified as M. fructicola (52%), 22 as M. fructigena (33%) and 10 as M. laxa (15%). Mycelial radial growth on water agar amended with thiophanate-methyl was measured to determine half maximal effective concentration values (EC50). All isolates of M. laxa and M. fructigena showed as sensitive, with EC50 values lower than 1 µg ml− 1 in 31 from 32 isolates. In M. fructicola, 19 isolates (56%) were sensitive, nine (26%) were resistant (EC50 2–30 µg ml− 1), and six (18%) were highly resistant (EC50 > 30 µg ml− 1). Positive allele-specific PCR with primer pair HRR/HRF, detecting resistant point mutations in β-tubulin gene, was recorded in 15 out of 16 highly resistant, resistant and less sensitive M. fructicola isolates. Among all species, PCR assay coincided with agar assay in 95% of cases. Highly resistant M. fructicola isolates AL 24/19 and VR 8/18 caused typical brown rot on nectarine fruits inoculated with conidia suspended in 5 or 10 µg ml− 1 of thiophanate-methyl. Four sensitive isolates of all three species did not develop on inoculated fruits. Besides implications for brown rot management, the finding of M. fructicola strains resistant to thiophanate-methyl may indicate that this species could be adapting to fungicides more rapidly than M. laxa or M. fructigena. As resistant M. fructicola isolates were also found in orchards where benzimidazoles have never been used, there is a possibility they originate from already benzimidazole-resistant strains which entered and established in Croatia.

Osjetljivost fitopatogene gljive Botrytis cinerea na fungicide fenheksamid i boskalid istražena je u 2018., 2019. i 2021. godini. Ukupno 46 izolata B. cinerea s vinove loze, jagode, borovnice, salate, tikvica, rajčice, graha i različitog ukrasnog bilja sakupljeno je širom Hrvatske. Za testiranje osjetljivosti na obje aktivne tvari odabrane su diskriminatorne koncentracije od 1 mg/l i 50 mg/l na agar podlogama. Niti jedan izolat B. cinerea nije pokazao rezistentnost na fenheksamid. Izduživanje kličnih cijevi svih izolata bilo je ispod 40 % od kontrole na 1 mg/l fenheksamida. Izduživanje kličnih cijevi svih izolata bilo je zaustavljeno na 50 mg/l fenheksamida. Ukupno 35 izolata B. cinerea (77 %) pokazalo se osjetljivima i na boskalid. Sedam izolata s vinove loze i jagode pokazalo je smanjenu osjetljivost, s izduživanjem kličnih cijevi do 86 % od kontrole na 1 mg/l te do 33 % od kontrole na 50 mg/l boskalida. Četiri izolata, sakupljena s jagode, tikvica, salate i rajčice pokazalo se rezistentnima na boskalid. Konidije rezistentnih izolata klijale su do 49 % od kontrole i stvarale kolonije na 50 mg/l boskalida. Rezultati pokazuju nužnost primjene strategije sprječavanja rezistentnosti u suzbijanju B. cinerea., In 2018, 2019 and 2021, screening on sensitivity of plant pathogenic fungus Botrytis cinerea to botryticides fenhexamid and boscalid was performed. Fortysix B. cinerea isolates from grapevine, strawberry, blueberry, lettuce, zucchini, tomato, bean and various ornamental plants have been randomly collected across Croatia. Discriminatory concentrations of 1 mg/l and 50 mg/l in agar assays have been selected for sensitivity testing, both for fenhexamid and boscalid. Neither one B. cinerea isolate showed resistance to fenhexamid. Conidial germ tube elongation of all isolates was less than 40% of control at 1 mg/l fenhexamid, and neither one isolate was capable of non-stalled germ tube elongation at 50 mg/l fenhexamid. Thirty-five (77%) B. cinerea isolates showed to be sensitive to boscalid. Seven isolates from strawberry and grapevine showed decreased sensitivity, with germ tube elongation up to 81% of control at 1 mg/l and up to 33% of control at 50 mg/l boscalid. Four isolates, collected from strawberry, zucchini, lettuce and tomato were determined as resistant to boscalid, with conidia capable of germination, germ tube elongation and colony forming at 50 mg/l boscalid. Conidia of resistant isolates germinated up to 49% of control and formed colonies at 50 mg/l boscalid. The results are pointing out the need for permanent resistance management in B. cinerea control.

Virusi jabuke, kruške ili dunje relativno su slabo poznati stručnjacima i voćarima. Najvažnijim virusima koji se javljaju na jezgričavim voćnim vrstama smatraju se virus mozaika jabuke (Apple mosaic virus, ApMV), virus klorotične pjegavosti lista jabuke (Apple chlorotic leaf spot virus, ACLSV), virus brazdavosti debla jabuke (Apple stem grooving virus, ASGV) i virus jamičavosti debla jabuke (Apple stem pitting virus,ASPV). U radu je ukratko opisana njihova važnost, biologija i regulativni status, kao i osnovne mjere zaštite., Virus diseases of apple, pear and quince are relatively less known to agricultural experts and fruit producers. Apple mosaic virus (ApMV), Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) and Apple stem pitting virus (ASPV) are usually considered economically most important viruses of pome fruit. Their significance, biology and regulatory status are briefly described, as well as basic control measures.

During the last decade anthracnose has become a major disease of Satsuma mandarin, the most important citrus crop in Croatia. The aim of this study was to determine Colletotrichum species associated with different symptoms and to identify the origin of inoculum. From 2013 to 2016, 437 samples of plant material were collected. Colletotrichum spp. was isolated from 93% of dried twigs, 35% of dropped flowers, 89% of leaf spots, all fruit (100%) with anthracnose or calyx-end rot symptoms, 12% of fruit with post-harvest soft rot and from 40% of fruit showing spots remaining on trees after harvest. Out of 258 Colletotrichum isolates, 253 has been morphologically identified as C. gloeosporioides (Penz.) Penz. & Sacc. species complex. Twenty-seven representative isolates were selected for phylogenetic analysis. Sequencing the inter-spacer gene region of ribosomal DNA confirmed the identity of the species. Artificial inoculation of flowers led to more than 2-fold higher young fruit drop compared to control. Pathogenicity tests on green fruit induced typical anthracnose symptoms on 82% of inoculated fruit two months after inoculation. Inoculation of mature fruit caused the appearance of typical anthracnose symptoms on 87% of inoculated fruit. These results showed that C. gloeosporioides species complex is responsible for different disease types on Satsuma mandarin, and that the fungus is present throughout the year on different plant organs., Antraknoza je tijekom prošlog desetljeća postala gospodarski štetna bolest mandarine Unshiu, najvažnije vrste agruma u Hrvatskoj. Cilj rada bio je istražiti. Colletotrichum vrste povezane s različitim simptomima na mandarini te utvrditi izvor zaraze. Od 2013. do 2016. sakupljena su 437 uzorka biljnog materijala. Colletotrichum vrste izolirane su iz 93 % osušenih izbojaka, 35 % otpalih cvjetova, 89 % lisnih pjega, iz svih plodova (100 %) sa simptomima antraknoze ili truleži čaške, 12 % plodova s mekom truleži u skladištu te iz 40 % plodova s pjegama koji su ostali na stablu nakon zime. Od ukupno 258 Colletotrichum izolata, 253 je morfološki determinirano kao C. gloeosporioides (Penz.) Penz. & Sacc. kompleks. Dvadeset sedam izolata odabrano je za filogenetsku analizu. Sekvenciranjem ITS regije gena ribosomske DNA potvrđena je identifikacija vrste. Umjetna zaraza cvjetova uzrokovala je više nego dvostruko veće otpadanje mladih plodića mandarine u usporedbi s kontrolom. Testovi patogenosti na nezrelim zelenim plodovima doveli su do pojave tipičnih simptoma antraknoze na 82 % inokuliranih plodova dva mjeseca nakon umjetnih zaraza. Inokulacija zrelih ubranih plodova uzrokovala je pojavu tipičnih simptoma antraknoze na 87 % inokuliranih plodova. Rezultati istraživanja pokazali su da je C. gloeosporioides kompleks vrsta uzročnik različitih tipova bolesti na mandarini Unshiu, kao i da je patogen prisutan na različitim biljnim organima tijekom cijele godine.

Leaf mould (Passalora fulva) has emerged as an important disease of greenhouse-growing tomato crops in Croatia during the last decade. In order to establish sustainable control measures, the presence of P. fulva races was investigated, in vitro sensitivity of the fungus to several fungicidal products was tested, and susceptibility of some old tomato varieties was checked. Seventeen isolates were collected from different parts of Croatia and inoculated on tomato cv. ‘Moneymaker’ differentials with different resistance genes (Cf-2, Cf-4, Cf-5 and Cf-9) or without resistance genes (Cf-0). Based on symptoms appearance assessment, 11 isolates were determined as P. fulva race 2, two isolates as race 5, one isolate as race 2.5 and three isolate as race 0. Sequence analysis of the Avr2 gene of five P. fulva race 2 isolates showed and insertion of adenine at 117_119 bp compared to the reference Avr2 wild-type gene retrieved from GenBank®, which leads to amino acid change from Tyrosine to Valine (p. Tyr41ValfsX1) in Avr2 protein. Pathogenicity tests with a P. fulva race 2 isolate on seven old tomato varieties lead to the development of leaf mould symptoms on four of seven varieties. Sensitivity of a selected P. fulva race 2 isolate was examined on agar plates amended with four fungicides products which were authorized in Croatia at that time for control different diseases on tomato. According to the results, Signum® was significantly and constantly the most effective product across all assessment periods.

Eska je gljivična bolest drveta vinove loze koja se javlja sve češće i nanosi sve veće štete u hrvatskom vinogradarstvu. U članku je ukratko opisana trenutačna situacija s eskom u Hrvatskoj i svijetu te je dat pregled suvremenih pristupa i mjera zaštite od bolesti., Esca is a trunk disease of grapevine with increasing incidence and severity in Croatia. Current situation with esca in Croatia and worldwide is briefly described in the article. Control and management options are presented.

Tijekom 2020. uočeni su u Zadru, Viru i Sutivanu na Braču simptomi propadanja kanarskih palma koji se nisu mogli pripisati palminoj pipi ili palminu drvotoču. Stariji vanjski listovi krošnje sušili su se, krošnja je bila rijetka, a novi mladi listovi manji i klorotični. Uočeno je sušenje polovice listova te pojava tamnih pruga uzduž peteljke i glavne žile. Iz simptomatičnih listova izoliran je Fusarium oxysporum, koji je na temelju simptomatologije, biljke domaćina i molekularne analize sekvenci EF-1α regije identificiran kao F. oxysporum f. sp. canariensis, uzročnik fuzarijskog venuća kanarske palme. U radu su ukratko opisane biologija, štetnost i mjere zaštite od bolesti, utvrđene prvi put u Hrvatskoj, i potencijalne nove prijetnje za kanarske palme duž jadranske obale., During 2020, symptoms of Canary Island date palm decline not similar to those caused by red palm weevil or palm borer were noticed in Zadar, in Vir and in Sutivan, the Island of Brač. Older, lower leaves of the canopy were dying, the canopy was poor, while younger leaves were smaller and chlorotic. Leaflets on only one side of the rachis were dried, and dark streaks were visible along petioles. Fusarium oxysporum was isolated from symptomatic leaves. Isolates were identified on the basis of EF-1α region sequencing, symptomatology and host as F. oxysporum f. sp. canariensis, the causal agent of Fusarium wilt of Canary Island date palm. Disease biology, impact and management are briefly described in the article. Fusarium wilt of Canary Island date palm is recorded for the first time in Croatia, representing a new threat for this valuable ornamental plant species along the Eastern Adriatic coast.

Plamenjača vinove loze jedna je od najpoznatijih biljnih bolesti uopće. U članku je dat kratak osvrt na kemijske mjere zaštite od bolesti., Grapevine downy mildew is one of the best-known plant diseases. Chemical control measures are briefly described in the article.

Trulež plodova pitomog kestena uzrokovana parazitskim gljivama može predstavljati značajan problem u plantažnoj proizvodnji te kulture. Tijekom 2018. godine, jaka pojava truleži plodova kestena zabilježena je u mješovitoj plantaži pitomog kestena i oraha u okolici Našica. U nasadu je sakupljeno 78 plodova (sorte Bouche de Betizac, Marsol i Maraval), među kojima su laboratorijskim pregledom u njih 63 utvrđeni simptomi truleži jezgre. Iz svih simptomatičnih plodova izolirane su gljive. Kombiniranom identifikacijom na temelju morfologije i analize sekvenci ITS1-5.8S-ITS2 ribosomske DNA, gljive iz simptomatičnih plodova determinirane su kao Gnomoniopsis smithogilvyi, Neofusicoccum parvum, Botryosphaeria dothidea, Diaporthe eres i Fusarium proliferatum. Vrsta G. smithogilvyi utvrđena je u 47 od 63 ploda (75 %), nakon koje su po zastupljenosti slijedile B. dothidea (11/63 ploda, 17 %), N. parvum (10/63 ploda, 16 %), D. eres (3/63 ploda, 5 %) i Fusarium sp. (1/63 ploda, 1,6 %). U 45 plodova utvrđena je samo jedna vrsta gljive, po dvije vrste nađene su u 11 plodova, a po tri vrste gljive u sedam plodova. Sve gljive utvrđene su na plodovima pitomog kestena u Hrvatskoj po prvi puta. Među njima ističe se prvi nalaz G. smithogilvyi, patogena koji u proteklih nekoliko godina uzrokuje velike štete na plodovima kestena u Europi.

Verticillium wilt, caused by Verticillium dahliae is considered the most serious biotic threat to olive trees. The disease is detected in almost all regions where olive is cultivated, and it may cause olive decline and dieback. The aim of this study was to determine the incidence and distribution of Verticillium wilt on olive trees in Istria (Croatia), to identify pathotype groups and race structure of the local V. dahliae population and to determine the susceptibility of Croatian olive cultivars to Verticillium wilt. In a field survey, Verticillium wilt was found to be the most common cause of olive decline, as it was detected in 61% of investigated locations. Out of 78 isolates of potentially pathogenic fungi obtained from olive trees with decline or dieback symptoms, 36% isolates of V. dahliae were determined. Molecular identifications based on PCR with specific primer sets showed that all V. dahliae isolates belonged to the nondefoliating pathotype (ND) and race 1. Olive cultivars Buža, Karbonaca, Istarska Bjelica, Rosinjola and Leccino were selected for susceptibility experiments, performed in a greenhouse, with a mix of three indigenous ND race 1 V. dahliae isolates used as inoculum. Different susceptibilities of local olive cultivars to V. dahliae infection were observed, with cultivar Karbonaca scoring as the most resistant. To the best of our knowledge, this is the first study showing Verticillium wilt as a widespread olive disease in Istria, confirming for the first time in Croatia the presence of a less aggressive, nondefoliating pathotype and race 1.

Tijekom 2015. godine u Baranji je došlo do masovnog propadanja nasada marelice. Iako sve upućuje da je uzrok pojave smrzavanje, određen broj voćnjaka je pregledan kako bi se u njima utvrdila eventualna prisutnost biljnih bolesti. U osam nasada marelice u Baranji sakupljena su 63 uzorka sa stabala sa simptomima odumiranja te su analizirani na prisutnost patogena 'Candidatus Phytoplasma prunorum', uzročnika europske žutice koštičavog voća. Fitoplazma je utvrđena u četiri od osam nasada, ukupno u 15 od 63 uzoraka (24 %). Masovno propadanje marelice u Baranji tijekom 2015. nije povezano sa zarazom fitoplazme 'Ca. Phytoplasma prunorum', no prisutnost tog patogena potrebno je uzeti u obzir kod uzgoja osjetljivih voćnih vrsta i proizvodnje sadnog materijala na tom području., During 2015, a massive dieback of apricot trees in orchards was recorded in Baranja. Although all indicated that the main cause of such decline was freezing damage, several orchards were inspected to determine the possible presence of plant diseases. Sixty-three samples from trees with decline or dieback symptoms were collected in eight apricot orchards in Baranja, and tested for the presence of 'Candidatus Phytoplasma prunorum', the causal agent of European stone fruit yellows (ESFY). ESFY phytoplasma was identified in four out of eight orchards, in 15 out of 63 samples (24 %). Massive dieback of apricots in Baranja during 2015 was not caused by ESFY phytoplasma, but the presence of this pathogen should be taken into account when growing susceptible fruit species or producing planting material in this region.

Gljive iz roda Phaeoacremonium ubrajaju se među uzročnike eske i eski sličnih bolesti vinove loze. Od 2009. do 2014., u šest vinograda (Kutjevo, Ilok, Nadin, Buje i Vukomeričke Gorice) sakupljeno je 16 uzoraka trsova sa simptomima Petrijeve bolesti (mladi vinograd u Nadinu) ili eske (ostali vinogradi). U 13 uzoraka nađene su vrste iz roda Phaeoacremonium, od toga u pet uzoraka u savršenom stadiju (periteciji), a u ostalih osam uzoraka u kondijskom stadiju. Analizom izolata na temelju morfologije i analizom sekvenci ITS1-5.8S-ITS2 ribosomske DNA utvrđeno je da izolati pripadaju vrstama Phaeoacremonium mortoniae (11 izolata), P. aleophilum (jedan izolat) i P. rubrigenum (jedan izolat). Za pet izolata koji su dobiveni iz peritecija nađenih na uzorcima vinove loze utvrđeno je da pripadaju vrstama Togninia fraxinopennsylvanica (P. mortoniae), T. minima (P.aleophilum) i T. Rubrigena (P. rubrigenum). Rezultati predstavljaju prvi nalaz savršenih stadija Phaeoacremonium vrsta na vinovoj lozi u Hrvatskoj i upućuju na mogućnost da se spomenuti patogeni, uzročnici eske i eski sličnih bolesti, mogu razmnožavati konidijama i askosporama

In most countries of the world where citrus fruits are grown, including Croatia, several viruses and virus-like agents exist limiting the production and sale of citrus fruits. The most common among them is Citrus tristeza virus (CTV) which causes a decrease in tree fertility and lushness. The aim of this paper is to illustrate the large scale of consequences caused by the CTV in Spain during the 20th century. More than 44 million citrus trees grafted on sour orange (Citrus aurantim L) rootstock sourhad decayed over a period of 10 years due to the intensing spread of CTV. The approaches that addressed the problem of infection of large citrus growing areas in Spain will be presented. Based on the experience in Spain, this paper will show the possibilities of implementing systematic expert measures which would eradicate or minimize the presence of CTV in the area of the Neretva valley, the most important citrus growing area in Croatia. A large number of researches have been carried out on the presence and the outspread of CTV in the Neretva Valley from 2005 to 2019. During this period, the highest percentage of virus outspread was observed in 2006, when CTV was detected in 80% of the collected samples. The virus was regularly detected in the Neretva valley in all the years the research was conducted. The problem of CTV has been present for many years and the pathogen is still spreading, which indicates the need to take some measures to prevent this continuous spreading. Among the most important and effective measures is the control of viral diseases in the propagation materials and the mother blocks and planting virus-free plants in accordance with the provisions of the Ordinance on placing reproductive planting material and seedlings intended for fruit production on the market (OG 9/17, 39/20), which contain European Union Directives 2008/90 / EC, 2014/96 / EU, and 2014/98 / EU

Iako je pojava biljnih bolesti različita u svakoj sezoni, tijekom 2019. godine zabilježeno je nekoliko pojava koje se mogu smatrati novima ili manje uobičajenima u Hrvatskoj. Sezonu 2019. obilježila je jaka pojava bolesti uzrokovane gljivom Rhizoctonia solani na većem broju kultura, među kojima se ističe prvi nalaz na smilju. U svibnju i lipnju u jakom su se intenzitetu javljale meke truleži uzrokovane bakterijama iz roda Erwinia (Pectobacterium), koje su zabilježene na luku, krumpiru i kukuruzu. Na šećernoj repi javljala se trulež korijena (Aphanomyces cochlioides) u jakom intenzitetu. Gljiva Macrophomina phaseolina prvi je put u Hrvatskoj zabilježena na jagodi kao uzročnik truleži korijena, a termofilni patogen Sclerotium rolfsii nađen je na rajčici, paprici i tikvicama. Bilježi se sve veći broj slučajeva nematoda korijenovih kvržica (Meloidogyne spp.) na mrkvi, peršinu i celeru. Na salati u okolici Zagreba javila se bakterijska pjegavost (Xanthomonas campestris pv. vitians), a u nekim vinogradima sjeverozapadne Hrvatske tijekom srpnja iznenađujuće se javila crna trulež (Phyllosticta ampelicida = Guignardia bidwellii)., Although it is known that the occurrence of plant diseases vary in different seasons, several unusual, unexpected or new diseases have been recorded in Croatia during 2019. Frequent occurrence of diseases caused by Rhizoctonia solani on various hosts was noted, among which the first record on immortelle (Helichrysum italicum) can be mentioned. During May and June, a severe occurrence of soft rots caused by Erwinia (Pectobacterium) has been recorded on onion, potato and maize. The severity of sugar beet root rot (Aphanomyces cochlioides) was much higher than usual. Root rot and decline caused by Macrophomina phaseolina on strawberry has been recorded for the first time in Croatia. Tropical pathogen Sclerotium rolfsii has been found on tomato, pepper and zucchini. Root-knot nematodes (Meloidogyne spp.) are emerging on carrot, parsley and celery crops, while bacterial leaf spot (Xanthomonas campestris pv. vitians) has been recorded on lettuce in Zagreb County. Black rot (Guignardia bidwellii) unexpectedly caused damage in several vineyards in North-Western Croatia, a region where this disease was almost unknown.

U većini zemalja svijeta gdje se uzgajaju agrumi, pa tako i u Hrvatskoj, prisutni su pojedini štetni organizmi koji mogu ograničavati proizvodnju i prodaju agruma. Među njima, najpoznatiji je Citrus tristeza virus (CTV) koji uzrokuje smanjenje rodnosti i bujnosti stabala. Cilj ovog rada je na primjeru Španjolske prikazati velike razmjere posljedica koje je prouzrokovao CTV tijekom 20. stoljeća. Zbog intenzivnog širenja virusa unutar plantažnih nasada u razdoblju od 10 godina propalo je više od 44 milijuna stabala agruma nacijepljenih na podlogu gorke naranče (Citrus aurantim L.). Prikazati će se pristupi kojima su se u Španjolskoj rješavali problemi zaraze velikih uzgojnih područja agruma. Temeljem španjolskih iskustava prikazati će se mogućnosti provođenja sustavnih stručnih mjera na područje doline Neretve, najvažnijeg uzgojnog područja agruma u Hrvatskoj, kojima bi se širenje CTV-a svelo na najmanju moguću mjeru. Na području doline Neretve od 2005. do 2019. godine proveden je veći broj istraživanja prisutnosti i raširenosti CTV-a. Tijekom tog razdoblja, najveći postotak raširenosti virusa zabilježen je 2006. godine, kada je CTV utvrđen u 80 % uzoraka. Virus je redovito utvrđen u dolini Neretve u svim godinama u kojima su istraživanja provedena. Problem CTV-a je prisutan već dugi niz godina i patogen se i dalje širi, što nam ukazuje na potrebu poduzimanja mjera sprječavanja njegovog širenja. Među najvažnijim stručnim mjerama je kontrola prisutnosti virusa u sadnom materijalu i sadnja zdravog sadnog materijala prema odredbama Pravilnika o stavljanju na tržište reprodukcijskog sadnog materijala i sadnica namijenjenih za proizvodnju voća (NN 9/17, 39/20) u kojem su sadržane direktive Europske unije 2008/90/EZ, 2014/96/EU, i 2014/98/EU., In most countries of the world where citrus fruits are grown, including Croatia, several viruses and virus-like agents exist limiting the production and sale of citrus fruits. The most common among them is Citrus tristeza virus (CTV) which causes a decrease in tree fertility and lushness. The aim of this paper is to illustrate the large scale of consequences caused by the CTV in Spain during the 20th century. More than 44 million citrus trees grafted on sour orange (Citrus aurantim L) rootstock sourhad decayed over a period of 10 years due to the intensing spread of CTV. The approaches that addressed the problem of infection of large citrus growing areas in Spain will be presented. Based on the experience in Spain, this paper will show the possibilities of implementing systematic expert measures which would eradicate or minimize the presence of CTV in the area of the Neretva valley, the most important citrus growing area in Croatia. A large number of researches have been carried out on the presence and the outspread of CTV in the Neretva Valley from 2005 to 2019. During this period, the highest percentage of virus outspread was observed in 2006, when CTV was detected in 80% of the collected samples. The virus was regularly detected in the Neretva valley in all the years the research was conducted. The problem of CTV has been present for many years and the pathogen is still spreading, which indicates the need to take some measures to prevent this continuous spreading. Among the most important and effective measures is the control of viral diseases in the propagation materials and the mother blocks and planting virus-free plants in accordance with the provisions of the Ordinance on placing reproductive planting material and seedlings intended for fruit production on the market (OG 9/17, 39/20), which contain European Union Directives 2008/90 / EC, 2014/96 / EU, and 2014/98 / EU

Fuzarijska venuća tikvenjača uzrokuju specijalizirane forme gljive Fusarium oxysporum. Među njima, venuće dinje (F. oxysporum f. sp. melonis) i venuće lubenice (F. oxysporum f. sp. niveum) potencijalno su vrlo štetne i mogu uzrokovati velike gubitke u proizvodnji. Osim spomenutih venuća, na krastavcu se javlja i ono koje uzrokuje F. oxysporum f. sp. cucumerinum. U članku su ukratko opisane simptomatologija i biologija fuzarijskog venuća krastavca, dinje i tikve, uz osvrt na mjere zaštite., Fusarium wilts of cucurbits are caused by specialized forms of the fungus Fusarium oxysporum. Among these diseases, Fusarium wilt of melon (F. oxysporum f. sp. melonis) and watermelon (F. oxysporum f. sp. niveum) are economically the most important, with the potential to cause high yield losses. Beside wilts of melon and on watermelon, similar disease is also described on cucumber (F. oxysporum f. sp. cucumerinum). Symptomatology, biology and control of Fusarium wilts are briefly described in the article.

Virusne su bolesti gospodarski problem posvuda u svijetu i mogu uzrokovati ozbiljne ekonomske gubitke u proizvodnji tikvenjača. Najvažniji virusi na tikvenjačama koji se pojavljuju u svijetu su: virus mozaika krastavca (Cucumber mosaic virus, CMV), virus žutog mozaika tikvice (Zucchini yellow mosaic virus, ZYMV), virus mozaika lubenice (Watermelon mosaic virus, WMV) i virus mozaika bundeve (Squash mosaic virus, SqMV). U Hrvatskoj su virusne bolesti na tikvenjačama nedovoljno istražene, premda su sve vedi problem u proizvodnji. U ovom su radu opisani gospodarski najvažniji virusi na tikvenjačama, simptomi koje uzrokuju, način njihova širenja i zaštitne mjere., Viral diseases represent an economic risk everywhere in the world where cucurbits are grown, and can cause high losses in cucurbit production. The most important viruses on cucurbits in the world are Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV) and Squash mosaic virus (SqMV). In Croatia, viral diseases on cucurbits are poorly investigated despite their growing significance in cucurbit production. The most important viruses on cucurbits are described in the article, with brief description of symptoms they cause, the way they spread and the means for their control.

U proteklih nekoliko godina u Hrvatskoj su zabilježene relativno visoke štete od pojedinih bakterijskih i virusnih bolesti u proizvodnji rajčice i paprike. Uzročnici tih bolesti bile su bakterije Pseudomonas syringae pv. tomato i Clavibacter michiganensis ssp. michiganensis te virusi Tomato spotted wilt virus (TSWV) i Cucumber mosaic virus (CMV). U članku su ukratko opisani spomenuti patogeni, njihovo širenje te mjere zaštite., During the last several years, certain bacterial and viral diseases caused high losses in tomato and pepper production in Croatia. Causal agents of these diseases were Pseudomonas syringae pv. tomato, Clavibacter michiganensis ssp. michiganensis, Tomato spotted wilt virus (TSWV) and Cucumber mosaic virus (CMV). These pathogens are briefly described, with an emphasis on their way of spreading and control measures.

Prezentirani rezultati istraživanja osjetljivosti štetnih organizama na sredstva za zaštitu bilja.

Žuti lozin pauk (Eotetranychus carpini f. vitis (Oudemans)) gospodarski je važan štetnik vinove loze jugoistočne Europe. U vinogradima Istre, u 2018. i 2019. godini, uzrokovao je značajne štete. Štetnost žutoga lozinog pauka bila je izražena na crvenim sortama teran i refošk s crvenom peteljkom („Refosco dal peduncolo rosso“). Ovaj članak daje opis vrste E. carpini f. vitis, njezine biologije, štetnosti i mogućnosti suzbijanja na vinovoj lozi u Hrvatskoj., The yellow spider mite (Eotetranychus carpini f. vitis (Oudemans)) is an economically important pest of Southeast European grapevines. Significant damage from E. carpini was observed in the vineyards of Istria in 2018 and 2019. Yellow spider mite was injurious on the red varieties Teran and Refošk with red petiole ("Refosco dal peduncolo rosso"). This article gives description of E. carpini f. vitis, its biology, damage and management on grapevine in Croatia.

Razgranjeni volovod (Orobanche ramosa = Phelipanche ramosa) obligatno je parazitska biljka i jedna je od najštetnijih parazitskih cvjetnica u svjetskoj poljoprivredi. Prije nekoliko godina pojavio se u usjevima industrijske rajčice na sjeverozapadu Istre i od tada se širi. U članku je ukratko opisana vrsta O. ramosa, uz kratak pregled mogudnosti kemijskog suzbijanja te parazitske biljke na rajčici., Branched broomrape (Orobanche ramosa = Phelipanche ramosa) is a holoparasitic plant considered as one of the most important parasitic weeds in agriculture worldwide. Several years ago, broomrape emerged in processing tomato crops in north-western Istria, and it has continued to spread. O. ramosa is briefly described in the article, with a discussion on the possibility of its chemical control in tomato.

Arbuskularne mikorizne gljive (AMG) su korisni mikroorganizmi tla koji žive u obliku simbioze s korijenjem velikog broja biljnih vrsta, uključujući i većinu ekonomski važnih poljoprivrednih kultura, u koje se za područje Hrvatske ubraja i rajčica. Rajčica ima visoki stupanj prirodne sposobnosti vezivanja s AMG, čije su prednosti najvećim dijelom povezane s boljom kondicijom biljaka i otpornosti na različite biotske i abiotske čimbenike. Primjena AMG je ograničena proizvodnim uvjetima, između ostalih primjenom fungicida koja se redovito provodi u proizvodnji rajčice za suzbijanje gljivičnih bolesti. Iako se fungicidi u proizvodnji rajčice uglavnom primjenjuju folijarno, značajne količine primijenjene djelatne tvari mogu indirektno dospjeti u gornji sloj tla i negativno utjecati na razvoj AMG. Cilj ovog preglednog rada je, temeljem dostupnih literaturnih podataka i dosadašnjih istraživanja, prikazati kompatibilnost AMG i fungicida dozvoljenih u Hrvatskoj za primjenu u proizvodnji rajčice na otvorenome., Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms that persist on roots of a significant number of plant species through symbiosis, including most of the economically important agricultural crops, where tomato takes a significant place for the Croatian area. Tomato has a high natural ability to interact with AMF, the benefits of which are significantly related to improved plant condition and resistance to different biotic and abiotic factors. Implementation of AMF is limited by production conditions, such as by application of fungicides that is regularly conduced in tomato production for fungal disease management. Although in tomato production mainly foliar fungicides are applied, significant quantity of applied active ingredient may indirectly reach the upper soil layer and negatively affect AMF development. The aim of this paper was to, based on available literature and research findings, describe the compatibility of AMF with fungicides allowed for application in open-field tomato production.

Folodija uljane repice uočena je tijekom 2017. godine u Bjelovarskobilogorskoj, Koprivničko-križevačkoj i Sisačko-moslavačkoj županiji. 'Candidatus Phytoplasma asteris' potvrđena je u simptomatičnim biljkama. U članku je ukratko opisana spomenuta fitoplazmoza uljane repice., Oilseed rape phyllody was observed in 2017 in Bjelovar-Bilogora, Koprivnica-Križevci and Sisak-Moslavina County. 'Candidatus Phytoplasma asteris' was confirmed in symptomatic plants. Brief description of this phytoplasma disease of oilseed rape is given.

Increase in blueberry (Vaccinium corymbosum) cultivation in Croatia during the last several years raised an interest in pests and pathogens occurring on this fruit crop. Among them, fungus Diaporthe vaccinii (Phomopsis vaccinii) is currently regulated as a quarantine harmful organism. Diaporthe vaccinii is the causal agent of Phomopsis shoot blight and canker on blueberry, and the status of this regulated pathogen in Croatia has been unknown. From 2016 to 2018, an official survey was carried out in Croatian blueberry orchards to determine the eventual presence of D. vaccinii. Thirty-three visual inspections were performed in 24 blueberry orchards in 11 counties and the City of Zagreb, and 66 samples of twigs showing symptoms resembling Phomopsis twig blight and canker were collected. Diaporthe spp. were detected in 20 samples, and 20 isolates were collected. In the majority of samples (49) fungi from Botryosphaeriaceae family were found, alone or co-occurring with Diaporthe. Phylogenetic analysis of ITS1-5.8S-ITS2 ribosomal DNA sequences showed that all Diaporthe isolates collected can be identified as Diaporthe eres. The survey confirmed the status of D. vaccinii as the pathogen not known to occur in Croatia.

At the global level, the invasion of alien organisms is considered the second largest threat to biodiversity. The assumption is that the high allelopathic potential is one of the features that helps invasive plant species to spread to new areas. Allelopathic potential of 8 invasive plant species (donor species) and their impact on test-species was determined in the study. Donor species were velvetleaf (Abutilon theophrasti Med.), ragweed (Ambrosia elatior L.), jimsonweed (Datura stramonium L.), common cocklebur (Xanthium strumarium L.), tree of heaven (Ailanthus altissima (Mill.) Swingle), indigo bush (Amorpha fruticosa L.), Japanese knotweed (Reynoutria japonica Houtt.) and giant goldenrod (Solidago gigantea Aiton). Three cultivated plant species from 3 different plant families were used as test-species. Test-species were: oat (Avena sativa L.), oilseed rape (Brassica napus subsp. oleifera) and sunflower (Helianthus annuus L.). Water extracts made of whole plants of donor species were applied to the seeds of the test-species. High allelopathic potential was proven for all species included in experiment. Allelopathic effects were exclusively negative. Impact on germination for all species was much lower in relation to the impact on the radicle and shoot length of the test-species. Perennial donor species had a stronger allelopathic potential than annual donor species. Tree of heaven was the species with the strongest allelopathic potential. Its extracts inhibited germination, radicle and shoot length of oilseed rape by 19%, 94.88% and 98.91% respectively., Na globalnoj razini, invazije alohtonih organizama predstavljaju drugu najveću prijetnju bioraznolikosti. Pretpostavka je da je visok alelopatski potencijal jedna od značajki koja pomaže invazivnim biljnim vrstama u širenju na nova područja. U radu je određen alelopatski potencijal 8 invazivnih biljnih vrsta (donor vrsta) i njihov učinak na test-vrste. Donor vrste su bile europski mračnjak (Abutilon theophrasti Med.), pelinolisni limundžik (Ambrosia elatior L.), bijeli kužnjak (Datura stramonium L.), dikica (Xanthium strumarium L.), pajasen (Ailanthus altissima (Mill.) Swingle), amorfa (Amorpha fruticosa L.), japanski dvornik (Reynoutria japonica Houtt.), velika zlatnica (Solidago gigantea Aiton). Kao test-biljke korištene su 3 kultivirane biljne vrste iz 3 različite biljne porodice: zob (Avena sativa L.), uljana repica (Brassica napus L.) i suncokret (Helianthus annuus L.). Vodeni ekstrakti napravljeni od cijelih biljaka donor vrsta aplicirani su na sjeme test-vrsta. Dokazan je visok alelopatski potencijal za sve vrste uključene u istraživanje. Alelopatski učinci bili su isključivo negativni. Učinak na klijavost svih vrsta mnogo je manji u odnosu na učinak na duljinu korjenčića i klica test-vrsta. Kod višegodišnjih donor vrsta zabilježen je jači alelopatski potencijal nego kod jednogodišnjih donor vrsta. Pajasen (Ailanthus altissima (Mill.) je vrsta s najjačim alelopatskim potencijalom. Njegovi ekstrakti inhibirali su klijanje, duljinu korjenčića i klice uljane repice za 19%, 94,88% i 98,91%.

Trulež plodova pitomog kestena uzrokovana parazitskim gljivama može predstavljati značajan problem u plantažnoj proizvodnji te kulture. Tijekom 2018. godine, jaka pojava truleži plodova kestena zabilježena je u mješovitoj plantaži pitomog kestena i oraha u okolici Našica. U nasadu je sakupljeno 78 plodova (sorte Bouche de Betizac, Marsol i Maraval), među kojima su laboratorijskim pregledom u njih 63 utvrđeni simptomi truleži jezgre. Iz svih simptomatičnih plodova izolirane su gljive. Kombiniranom identifikacijom na temelju morfologije i analize sekvenci ITS1-5.8S-ITS2 ribosomske DNA, gljive iz simptomatičnih plodova determinirane su kao Gnomoniopsis smithogilvyi, Neofusicoccum parvum, Botryosphaeria dothidea, Diaporthe eres i Fusarium proliferatum. Vrsta G. smithogilvyi utvrđena je u 47 od 63 ploda (75 %), nakon koje su po zastupljenosti slijedile B. dothidea (11/63 ploda, 17 %), N. parvum (10/63 ploda, 16 %), D. eres (3/63 ploda, 5 %) i Fusarium sp. (1/63 ploda, 1,6 %). U 45 plodova utvrđena je samo jedna vrsta gljive, po dvije vrste nađene su u 11 plodova, a po tri vrste gljive u sedam plodova. Sve gljive utvrđene su na plodovima pitomog kestena u Hrvatskoj po prvi puta. Među njima ističe se prvi nalaz G. smithogilvyi, patogena koji u proteklih nekoliko godina uzrokuje velike štete na plodovima kestena u Europi., Nut rot caused by pathogenic fungi can represent a significant problem in sweet chestnut production. During 2018, a severe occurrence of nut rot in sweet chestnut was recorded in a mixed chestnut-walnut orchard near Našice in Eastern Croatia. Seventy-eight nuts (cvs. Bouche de Betizac, Marsol and Maraval) were collected and inspected in laboratory. Rot symptoms were detected in 63 nuts. Fungi were isolated from all symptomatic nuts. By combining morphological identification and analysis of ITS1-5.8S-ITS2 ribosomal DNA sequences, fungi were identified as Gnomoniopsis smithogilvyi, Neofusicoccum parvum, Botryosphaeria dothidea, Diaporthe eres and Fusarium proliferatum. Species G. smithogilvyi was found in the highest incidence, in 47 out of 63 nuts (75 %), followed by B. dothidea (11/63 nuts, 17 %), N. parvum (10/63 nuts, 16 %), D. eres (3/63 nuts, 5 %) and Fusarium sp. (1/63 nuts, 1.6 %). A single fungal species was recorded in 45 nuts, while mixed infections of two species or three species were recorded in 11 and seven nuts, respectively. All fungi were found on sweet chestnut for the first time in Croatia. A record of G. smithogilvyi is especially relevant, as this species has been reported to have caused extensive damage in sweet chestnut production in Europe in the last years.

Istraživanje pojave sušenja stabala maslina u Istri provedeno je tijekom 2016. i 2017. godine. Zbog određivanja uzročnika koji bi mogli biti odgovorni za navedenu pojavu obavljeni su vizualni pregledi stabala i uzorkovanje biljnoga materijala. Uzorci biljnog materijala prikupljeni su na 23 lokacije unutar četiri maslinarska uzgojna područja: bujsko-umaškom, porečko-vrsarskom, rovinjskom i vodnjansko-pulskom. Navedena uzgojna područja razlikovala su se po mikroklimatskim obilježjima, sortimentu, starosti stabala te svojstvima tla. Identifikacija pojedinih uzročnika bolesti obavljena je u specijaliziranom mikološkom laboratoriju. U simptomatičnim uzorcima ustanovljeno je nekoliko vrsta, rodova i porodica fitopatogenih gljiva. Za identifikaciju vrsta korištene su klasične (uzgoj na hranjivim podlogama i analiza morfologije izolata) i molekularne (PCR i sekvenciranje) metode dijagnostike. Ukupno je sakupljeno 78 izolata. Najčešće izolirana vrsta fitopategene gljive, a koja bi mogla biti uzročnik djelomičnog ili potpunog sušenja, slabijeg rasta i slabijeg vigora maslina, bila je vrsta Verticillium dahliae Kleb. Osim te u simptomatičnim uzorcima ustanovljene su i Diplodia seriata, gljiva iz porodice Botryosphaeriaceae, te Armillaria mellea, uzročnik bijele truleži korijena. Prisutnost vrsta V. dahliae (na 57 % lokacija) i A. mellea (na 17 %) potvrđena je u svim maslinarskim uzgojnim područjima obuhvaćenim ovim istraživanjem, dok je prisutnost vrste D. seriata (na 13 % lokacija) ustanovljena samo u maslinicima u okolici Rovinja i Bala., The appearance of decline of olive trees in Istria during the years 2016 and 2017 was investigated. To determine the possible causative agents that could be related to that phenomenon, visual examinations of trees and collection of samples of plant material were carried out. Samples of plant material were collected on 23 locations, within four olive growing areas: Buje-Umag, Poreč-Vrsar, Rovinj and Vodnjan-Pula. Surveyes olive growing areas differed by microclimatic features, varieties, age of trees and soil properties. Identification of particular causative agents of diseases was performed in a specialized mycological laboratory. Several species, genera and families of phytopathogenic fungi has been identified in symptomatic samples. For the identification of species, classical (cultivation and analysis of isolate morphology) and molecular methods (PCR and sequencing) has been used. A total of 78 isolates were collected. The most common isolated species of phytopathogenic fungi, which could be the causative agent of partial or total decline, weaker growth and lower vigor of olives was the species Verticillium dahliae Kleb. Beside that, in symptomatic samples, Diplodia seriata, fungal species of the family Botryosphaeriaceae and Armillaria mellea, the causative agent of white root rot, were found. The oresence of Verticillium dahliae (on 57% of locations) and Armillaria mellea (on 17%) have been determined in all olive growing areas covered by this work, while the presence of D. seriata (on 13% of locations) have been determined only in olive groves in the area of Rovinj and Bale.

U Hrvatskoj je tijekom 2015. godine istraživana eventualna prisutnost fitopatogene gljive Diplocarpon mali, uzročnika zvjezdaste pjegavosti jabuke. Od kolovoza do studenog provedena su 23 vizualna pregleda jabuke u intenzivnim i ekstenzivnim nasadima, okućnicama i na javnim površinama u deset županija. Sakupljeno je 50 uzoraka listova jabuke koji su laboratorijski analizirani. Gljiva D. mali utvrđena je u 21 uzorku. Zvjezdasta pjegavost utvrđena je u uzorcima sakupljenima u Zagrebačkoj, Sisačko – moslavačkoj, Varaždinskoj i Međimurskoj županiji te u Gradu Zagrebu. Na svim lokacijama gdje je bolest nađena uočeno je žućenje zaraženih listova i rana defolijacija. Zvjezdasta pjegavost jabuke po prvi je puta utvrđena u Republici Hrvatskoj., The possible presence of Marssonina leaf blotch of apple, caused by the fungus Diplocarpon mali, was investigated in Croatia during 2015. Twenty-three visual inspections of apple trees in intensive and extensive orchards, gardens and public areas were conducted from August to November in ten counties. Fifty samples of apple leaves were collected and analysed in laboratory. D. mali was identified in 21 samples. Marssonina leaf blotch was found in samples collected in Zagreb County, Sisak – Moslavina County, Varaždin County, Međimurje County and in the City of Zagreb. Yellowing of leaves and premature leaf drop were observed at locations where Marssonina leaf blotch was determined. This is the first report of Marssonina leaf blotch of apple in Croatia.

To assess the potential impact and control options for Monilinia fructicola, the alien stone fruit pathogen in Croatia, development of pre-harvest and post-harvest brown rot was monitored during 2014 and 2015 in a peach orchard where integrated pest management measures are implemented. Two experimental locations, A (younger part of the orchard with a lower elevation) and B (older part with higher elevation) were established, and conditions for infection were monitored using a forecast model for M. fructicola with PinovaSoft ® application. In 2014, symptoms of brown rot in the field were recorded only on fruits at location B, with 6.6% incidence. Monilinia spp. developed on 92.6% of stored fruits from location A and on 20.3% of stored fruits from location B. Out of 40 isolates collected from the fruits at the moment of harvest, 27% were M. fructicola, 30% were Monilinia laxa, and 43% were Monilinia fructigena. Similar percentages of three Monilinia species were determined on stored fruits. In 2015, no fruits affected with brown rot were found at the moment of harvest, but only after 21 days of storage and only on fruits from location B, with low incidence (8% fruits). M. fructicola was found on all fruits with brown rot symptoms, while M. laxa and M. fructigena were detected only on three fruits in mixed infections with M. fructicola. Despite differences in brown rot incidence between years, forecast model recorded seven infections with M. fructicola during the vegetation period in 2014 and 15 infections in 2015. Th e results are indicating that common measures against indigenous M. laxa and M. fructigena may be suitable for the control of invasive M. fructicola, and that all three Monilinia species on peach in Croatia can occur in mixed populations.

Zvjezdasta pjegavost bolest je jabuke koju uzrokuje gljiva Diplocarpon mali anamorf [Marssonina coronariae (Ellis & Davis) Davis]. Jaka zaraza dovodi do rane defolijacije stabala. Bolest je u Europi prvi puta zabilježena 2001. godine, a u posljednjih nekoliko godina zabilježene su prve štete u ekološkim voćnjacima jabuke. U Hrvatskoj je bolest prvi puta potvrđena 2015. godine. U radu su ukratko opisani simptomi bolesti, biologija gljive uzročnika i mjere zaštite od bolesti., Marssonina leaf blotch is an apple disease caused by the fungus Diplocarpon mali (imperfect state Marssonina coronaria). Severe infection can lead to the early defoliation of trees. The disease was recorded in 2001 for the first time in Europe. During the last few years, first losses have been recorded in organic apple orchards. Marssonina leaf spot was found in Croatia for the first time in 2015. The article briefly describes disease symptoms, biology of the fungus D. mali and disease control measures.

Gljiva Armillari amellea uzročnik je truleži korijena mnogih voćnih vrsta i vinove loze. Tijekom posljednjih nekoliko godina zabilježena je češća pojava gljive A. mellea na maslini u Hrvatskoj. Bolest uzrokuje odumiranje stabala i u pojedinim slučajevima može se smatrati ekonomski značajnom. U članku su ukratko opisani simptomi bolesti te mogućnosti zaštite masline od A. mellea otkopavanjem korijena i primjenom bioloških sredstava na osnovi Trichoderma vrsta., Basidiomycete fungus Armillaria mellea is the causal agent of root rot on many fruit species and on grapevine. Several outbreaks of A. mella on olive have been recorded in Croatia during the last few years. A. mellea causes decline and mortality of olive trees and can be regarded as economically important in particular cases.Armillaria root rot symptoms on olive and the possibility of disease management with root collar excavation or with Trichoderma‐based biological products are briefly described in the article.

Background and Purpose: Eutypella parasitica, a plant pathogenic fungus attacking maples (Acer spp.) was detected for the first time in Croatia in 2007. From 2007 to 2014, it was found only in forests, on several trees in Hum na Sutli, near Slovenian border. In 2015, the presence of Eutypella parasitica was monitored for the first time in urban areas. Materials and Methods: Within the official survey programme, 23 visual surveys were conducted and 24 samples were collected and analysed for the presence of fungi. E. parasitica was found in Bundek Park in Zagreb. Typical symptoms of Eutypella canker were detected on two field maples (Acer campestre) and two boxelder maples (Acer negundo). Twelve isolates were collected from symptomatic trees. Conclusions: Eleven out of twelve isolates from four trees were confirmed as E. parasitica by species-specific polymerase chain reaction. This is the first report of E. parasitica in Zagreb, the first record of E. parasitica in Croatia outside forests, as well as a record of a new host species in Croatia, boxelder maple (A. negundo). Introduction pathway of E. parasitica in Zagreb remains unknown.

Relativno je malo objavljenih radova o istraživanjima rezistentnosti fitopatogenih gljiva i pseudogljiva na fungicide u Hrvatskoj. Tijekom proteklih 30‐ak godina zabilježeni su slučajevi pada učinkovitosti benzimidazola (karbendazim i benomil) na pjegavost lista šećerne repe (Cercospora beticola), metalaksila na plamenjaču krumpira (Phytophthora infestans), nekih triazola i strobilurina na pepelnicu vinove loze (Erysiphe necator) i dikarboksimida (vinklozolin i iprodion) na sivu plijesan (Botrytis cinerea). Rezistentnost B. cinerea na dikarboksimide i rezistentnost E. necator na inhibitor biosinteze ergosteloa triadimefon dokazani su i laboratorijski. Istraživanja fenotipske varijabilnosti gljive B. cinerea pokazala su da unutar populacija patogena na vinovoj lozi i na jagodi postoje jedinke rezistentne na pirimetanil, ciprodinil, fludioksonil i fenheksamid, ali javljaju se u vrlo malom postotku. Praćenje pojave rezistentnosti biljnih patogena na regionalnoj ili nacionalnoj razini važno je za postizanje racionalne, učinkovite i održive uporabe fungicida., Relatively low number of studies dealing with resistance of phytopathogenic fungi and Oomycetes to fungicides in Croatia is published and publically available. During the last 30 years, several cases of fungicide efficacy loss were recorded in field trials. A decrease in effectiveness was recorded for benzimidazoles (carbendazim and benomyl) in control of sugar beet Cercospora leaf spot (Cercospora beticola), for metalaxyl in control of potato late blight (Phytophthora infestans), for some triazoles and strobilurins in control of grapevine powdery mildew (Erysiphe necator), and for dicarboximides (vinclozolin and iprodione) in control of grey mould (Botrytis cinerea). Resistance of B. cinerea to dicarboximides and resistance of E. necator to IBE fungicide triadimefon were proven in laboratory experiments. Studies on phenotypic variability of B. cinerea in Croatia showed that isolates resistant to pyrimethanil, cyprodinil, fludioxonil and fenhexamid are present in populations of the fungus on grapevine and on strawberry, but in very low percentage. Resistance monitoring on regional or national level is important for achieving rational, effective and sustainable use of fungicides in agriculture.

Green mould disease, caused by Trichoderma species, is a severe problem for mushroom growers worldwide, including Croatia. Trichoderma strains were isolated from green mould-affected Agaricus bisporus (button or common mushroom) compost and Pleurotus ostreatus (oyster mushroom) substrate samples collected from Croatian mushroom farms. The causal agents of green mould disease in the oyster mushroom were T. pleurotum and T. pleuroticola, similar to other countries. At the same time, the pathogen of A. bisporus was exclusively the species T. harzianum, which is different from earlier findings and indicates that the range of mushroom pathogens is widening. The temperature profiles of the isolates and their hosts overlapped, thus no range was found that would allow optimal growth of the mushrooms without mould contamination. Ferulic acid and certain phenolic compounds, such as thymol showed remarkable fungistatic effect on the Trichoderma isolates, but inhibited the host mushrooms as well. However, commercial fungicides prochloraz and carbendazim were effective agents for pest management. This is the first report on green mould disease of cultivated mushrooms in Croatia

Several species of the genus Fusarium can cause apple fruit to rot while stored. Since Fusarium taxonomy is very complex and has constantly been revised and updated over the last years, the aim of this study was to identify Fusarium species from rotten apples, based on combined morphological characteristics and molecular data.We identified 32 Fusarium isolates from rotten apple fruit of cultivars Golden Delicious, Jonagold, Idared, and Pink Lady, stored in Ultra Low Oxygen (ULO) conditions. Fusarium rot was detected in 9.4 % to 33.2 % of naturally infected apples, depending on the cultivar. The symptoms were similar in all four cultivars: a soft circular brown necrosis of different extent, with or without visible sporulation. Fusarium species were identified by the morphology of cultures grown on potato-dextrose agar (PDA) and carnation leaf agar (CLA). Twenty one isolates were identified as Fusarium avenaceum and confirmed as such with polymerase chain reaction (PCR) using specific primer pair FA-ITSF and FA-ITSR. F. pseudograminearum,F. semitectum, F. crookwellense, and F. compactum were identified by morphological characteristics. F.avenaceum can produce several mycotoxins and its dominance in Fusarium rot points to the risk of mycotoxin contamination of apple fruit juices and other products for human consumption. Pathogenicity tests showed typical symptoms of Fusarium rot in most of the inoculated wounded apple fruits. In this respect Fusarium avenaceum, as the dominant cause of Fusarium rot in stored apple fruits is a typical wound parasite.