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Pest and disease control in cultivated mushroom production in Serbia is mainly based on chemical pesticides that are toxic to non-target organisms, humans and the environment. The European and national policies, as well as the United Nations Sustainable Development Goals, strongly encourage the use of low-risk active ingredients and sustainable alternatives to chemical pesticides in mushroom disease and pest control. The mushroom fly, Lycoriella ingenua (Dufour) (Sciaridae: Diptera) is the most damaging mushroom pest in Serbia and globally. The aim of the study was to evaluate the virulence of two locally isolated populations of Steinernema feltiae (Filipjev) (strains P9 and K2) against the mushroom fly. Nematodes were reared on grater wax moth last instar larvae, and infective juveniles (IJ) not older than 15 days were used in the experiments. Experiments were conducted in plastic Petri dishes (35 mm in diameter) with the bottom surface covered with filter paper. Volume of 0.5 ml of nematode suspension containing 0, 50, 100, 200, 500, and 1000 IJ were applied to filter paper and 10 fourth larval instar of L. ingenua were added subsequently in each Petri dish. Every concentration of both nematode populations were replicated five times and whole experiment was repeated twice. The mortality of mushroom fly larvae was recorded three and seven days after exposure to nematodes. Log-probit regression analyses of the concentration-mortality data showed that both local populations of S. feltiae tested caused significant mortality of the fourth instar larvae of L. ingenua. In the dose-response bioassays, the following LC50s (median Lethal Concentrations) were estimated: 15.7718 and 18.2742 nematodes/larva (i.e. 16 and 18 IJ/cm2), for populations P9 and K2, respectively. Values LC90 for both populations corresponded with the highest IJ concentration used, around 100 IJ/cm2. A lethal dose ratio test showed that the local population P9 was significantly more virulent toward the

The mushroom industry in Serbia is growing rapidly, producing fresh mushrooms of different quality for consumption, processing or export. A lack of effective chemicals for disease control, and pathogen resistance to pesticides, consequentially lead to unsuccessful control of the green mold agent, Trichoderma aggressivum. The principles of sustainable use of pesticides require a change in the attitude of composters and mushroom growers towards biological disease control. Altering the microbial comunities in compost and casing soil to stimulate the growth of healthy button mushrooms will hopefully increase mushroom yield and green mold control, and provide a practice-based understanding of the microbial community-pathogen relationships. The objective of the study was to implement two indigenous beneficial microorganisms in the cultivation of button mushroom Agaricus bisporus: Bacillus amyloliquefaciens, strain B-241, a bacterium with fungicidal activity against T. aggressivum, and Streptomyces flavovirens, strain A06, an actinobacterium which stimulates mushroom yield. Interrelationship between the two beneficial microorganisms was investigated in an experimental mushroom growing room after inoculation with compost green mold, T. aggressivum f. europaeum, which was added one day after the spawned compost was placed in boxes (106 conidia/mL per m2). The concentration of beneficial bacterial and actinobacterial suspension was adjusted to 108 CFU/mL per m2 and applied at seven-day intervals. The synergy factor (SF) was calculated as a ratio between the observed and expected impact on yield or effectiveness in suppression of disease symptoms. The results indicated strong synergism in promoting A. bisporus productivity in both uninoculated (SF=1.56) and inoculated plots (SF=1.62) after combined application of the two beneficial microorganisms. Regarding efficacy in preventing green mold symptoms, the beneficial bacterium and actinobacterium displayed an additive effect (SF

The study was focused on improvement of integrated management strategy against the mushroom fly Lycoriella ingenua (Dufour) on the white button mushroom Agaricus bisporus (Lange) Imbach. Impact of different strains of entomopathogenic nematodes (EPN) Steinernema feltiae (Filipjev), commercial and two indigenous from Serbia (K2, P9), on regulation of mushroom sciarid fly and the influence on mushroom yield was evaluated. Experiment was conducted in air- conditioned mushroom growing chamber. Commercially produced phase III mushroom substrate were placed into 24 plastic containers (w 31 × d 21.5 × h 13 cm). Each plastic container was inoculated with 20 last instar larvae of L. ingenua. EPN were produced on last larval instars of Galleria mellonella L. and less than a week old infective juveniles (IJ) were used in the experiment. Nematode suspension of each of the three EPN strains containing 50000 IJ were added on the substrate surface in each plastic container on the day before casing, at the casing time and seven days after casing. Containers were held in the insect rearing cages and density of adults of L. ingenua was observed weekly using yellow sticky traps inside each cage. Preliminary results of ongoing experiment showed the highest efficacy in pest control of commercial EPN strain, followed by two native strains. No statistically significant differences were found in efficacy between two Serbian strains. Also, no statistically significant differences in mushroom yield were observed among control and all treatments using different strains of EPNs.

Alelopatski efekti aktinobakterija na klijanje semena i rani porast klijanaca Teofrastove lipice (Abutilon theophrasti Medik.) REZIME Cilj ovog rada je bio da se ispitaju alelopatski efekti aktinobakterijskih izolata u in vitro uslovima na klijavost semena i rani porast klijanaca semena Abutilon theophrasti. Iz zemlje i komposta u različitim fazama kompostiranja dobijeno je 35 izolata aktinobakterija. Takođe, u ogled je uključen i tretman herbicidom (mezotrion) u preporučenoj količini primene, kao referentni standard. Na osnovu dobijenih rezultata može se utvrditi da postoji statistički značajna razlika (p lt 0,05) između kontrole (neinokulisana tečna skrobno-kazeinska podloga) i svih tretmana sa aktinobakterijskim izolatima na klijavost semena, dužinu korenka i stabaoceta. Najveća inhibicija (100%) klijanja semena i dužine korenka zabeležena je u tretmanima sa izolatima A10 i NOV2. Pokazalo se da je dužina stabaoceta osetljiviji parametar, jer je zabeležena inhibicija od 100% u većini tretmana A010, NOV2, NOV3, NOV4 i NOV5. Izolati aktinobakterija su pokazali veći inhibitorni efekat na klijanje semena u odnosu na tretman herbicidom mezotrionom., This study aimed to examine in vitro allelopathic effects of actinobacterial isolates on seed germination and early seedling growth of velvetleaf (Abutilon theophrasti). Thirty-five actinobacterial isolates were obtained from soil and compost in different phases of composting. Also, an experiment variant involving the herbicide mesotrione was set in the recommended amount of application, as a reference standard. The experimental results indicate statistically significant differences (p lt 0.05) between controls and all treatments with actinobacterial isolates regarding seed germination, and radical and shoot length. The highest inhibition (100%) was observed in seed germination and radical length in treatments with the isolates A10 and NOV2, compared to uninoculated starch casein broth (SCB) as control. Shoot length was shown to be the most sensitive parameter, where 100% inhibition was observed in the following treatments with actinobacteria: A010, A017, NOV2, NOV3, NOV4 and NOV5. Actinobacterial isolates showed a higher inhibitory effect on seed germination than treatment with the reference herbicide mesotrione.

The purpose of this study was to examine in vitro the herbicidal effect of an essential oil of dill (Anethum graveolens) on germination and early seedling growth of two parasitic flowering plants in the genus Cuscuta (Cuscuta campestris and C. epithymum), as well as its phytotoxic impact on germination and early seedling growth of two host plants (alfalfa and red clover). Chemical analysis of the essential oil extracted from dill leaves and flowers showed that carvone (51.69%) and limonene (39.88%) predominated. The results of a seed bioassay showed inhibitory effects of different concentrations (1%, 0.5%, 0.1%, and 0.01% v v-1) of the essential oil of dill leaves on germination and early seedling growth of both tested species of the genus Cuscuta. Germination of C. campestris seeds was inhibited between 67% and 94%, while seed germination of C. epithymum was inhibited between 67% and 100%. A similar inhibitory effect was observed regarding the seedling length parameter. Moreover, the bioassay results indicated significant phytotoxic effects of dill essential oil on the seed germination and early seedling growth of host plants. Red clover proved more sensitive as even the lowest concentration inhibited germination by 35%, while higher concentrations caused 70-100% inhibition. On the other hand, lower concentations inhibited germination of alfalfa seeds by 5%, while higher concentrations caused greater inhibition (36-100%). Future research should include both pot experiments and field micro-trials to determine herbicidal, i.e. phytotoxic, effects of dill essential oil on parasitic flowering plants and cultivated species, Cilj ovog rada je bio da se in vitro ispita herbicidni uticaj etarskog ulja mirođije (Anethum graveolens) na klijanje i rani porast klijanaca dve parazitne cvetnice iz roda Cuscuta (Cuscuta campestris i Cuscuta epithymum), kao i fitotoksični uticaj na klijanje semena i rani porast klijanaca semena domaćina (lucerka i crvena detelina). Hemijskom analizom etarskog ulja izolovanog iz listova i cvetova mirođije je dobijeno da su karvon (51.69%) i limonen (39.88%) dominantne komponente. Rezultati biotesta sa semenima su pokazali inhibitorni uticaj etarskog ulja izolovanog iz listova mirođije pri različitim koncentracijama na klijavost i rani porast klijanaca obe vrste roda Cuscuta. Naime, inhibicija klijanja semena C. campestris se kretala od 67% do 94%, dok je kod semena C. epithymum inhibicija bila od 67% do 100%. Sličan inhibitorni uticaj je zabeležen i za parametar dužina klijanaca. Pored ovoga, u rezultatima biotesta su zabeleženi značajni fitotoksični efekti etarskog ulja mirođije na klijanje semena i rani porast klijanaca domaćina. Crvena detelina se pokazala kao osetljivija, jer je i pri najnižoj koncentarciji inhibicija klijanja bila 35%, a pri višim se kretala od 70% do 100%. Nasuprot ovome inhibicija klijanja semena lucerke pri nižim koncentracijama je bila 5%, dok je na višim koncentracijama zabeležena veća inhibicija (36-100%). Buduća istraživanja moraju obuhvatiti oglede u saksijama, kao i poljske mikrooglede da bi se utvrdili herbicidni, odnosno fitotoksični efekti etarskog ulja mirođije na testirane parazitne cvetnice i gajene vrste.

The potential allelopathic effect of a green walnut fruit extract on seed germination and early growth of three weed species (Chenopodium album, Amaranthus retroflexus, Daucus carota) was tested, as well as its phytotoxic effect on seed germination and early growth of maize (Zea mays). Another objective was to analyze the plant extract and assess its antioxidative activity. Antioxidative activity of the plant extract was evaluated based on its ability to neutralize DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and capacity for iron reduction using the FRAP method. Inhibition of the evaluated parameters (total germination and seedling length) decreased proportionally with decreasing concentrations of extract solution of green walnut fruit. The parameters of seedling growth were also found to show greater susceptibility than total seed germination of all three of the tested weed species. Although the seed bioassay results indicated a high inhibitory effect on germination and early growth of the tested weeds, they also revealed phytotoxic activity during early growth of the cultivated Z. mays., Cilj ovog rada je bio da se ispita alelopatski potencijal ekstrakta zelenih nezrelih plodova oraha na klijanje i rani porast semena tri korovske vrste (Chenopodium album, Amaranthus retroflexus, Daucus carota), kao i fitotoksični efekat na klijanje i rani porast semena kukuruza Zea mays. Pored toga, cilj je bio i da se uradi analiza biljnog ekstrakta i procena njegove antioksidativne aktivnosti. Antioksidativna aktivnost biljnog ekstrakta određena je kroz sposobnost neutralizacije DPPH (2,2-difenil-1-pikrilhidrazil) radikala i ispitivanjem sposobnosti redukcije gvožđa FRAP metodom. Inhibicija merenih parametara (ukupna klijavost i dužina klijanaca) se proporcionalno smanjivala sa smanjenjem koncentracije rastvora ekstrakta zelenih nezrelih plodova oraha. Takođe, parametri rasta klijanaca su ispoljili veću osetljivost u odnosu na parametar ukupne klijavosti semena kod sve tri korovske vrste. Iako dobijeni rezultati iz biotesta sa semenima pokazuju značajan inhibitorni efekat na klijanje i rani porast testiranih korovskih vrsta, ujedno ukazuju i na fitotoksične efekte kod ranog porasta semena gajene vrste Z. mays.

Klomazon (IUPAC: 2-(2-hlorobenzil)-4,4-dimetil-1,2-oksazolidin-3-on) je selektivni herbicid iz grupe izoksazolidinona, koji se na osnovu svojih fizičko-hemijskih karakteristika može svrstati u grupu pesticida koji predstavljaju potencijalne kontaminante površinskih voda, dubljih slojeva zemljišta i podzemnih voda. Glina i organska materija, pre svega huminske kiseline (HA), su glavne sorbujuće komponente zemljišta. Literaturni podaci ukazuju da u sorpciji klomazona u zemljištu učestvuje ili organska materija [1-3]ili glina i organska materija [4,5]. S toga je cilj ovog radabio ispitati potencijal HA i glina izdvojenih iz različitih tipova poljoprivrednog zemljišta sa područja Republike Srbije (rendzina, černozem i smonica) u sorpciji klomazona, odnosno odrediti njihov remedijacioni potencijal. Za proučavanje sorpcionog ponašanja klomazona i određivanje njegovih sorpcionih konstanti (Kd) za pomenute supstrate je korišćen batch metod [6], zasnovan na ravnotežnoj raspodeli molekula klomazona u sistemu supstrat/vodena faza. U slučaju HA, sistem se sastojao od smeše 25 mg supstratai 2,5 mL rastvora određene koncentracije (0,5 – 25 g/mL)klomazona u 0,01 M CaCl2, dok je u slučaju glina sistem sadržao 250 mg gline i 2 mL pomenutih rastvora. Svaka smeša je homogenizovana 24 h radi dostizanja ravnotežne raspodele ovog jedinjenja između dve faze sistema. Nakon centrifugiranja, vodena faza je analizirana HPLC-om opremljenim sa PDA detektorom, pri čemu su Kd koeficijenti klomazona za proučavane supstrate računati kao odnos koncentracije pesticida koja je sorbovana za supstrat (Cs) i koncentracije jedinjenja koja je zaostala u vodenoj fazi (Ce), u uslovima ravnotežne raspodele. Adsorpcione izoterme su dobijene primenom Frojndlihove jednačine na eksperimentalno dobijene rezultate, pri čemu su Frojndlihovi koeficijenti Kf i n, dobijeni primenom linearne forme Frojdlihove jednačine. Dobijeni rezultati ukazuju da je sorpcija klomazona mnogo veća za HA nego za gline, i da opada u sle

Tehničko rešenje „Razvoj i primena metode za praćenje prorastanja lukovica crnog luka nakon primene herbicida-regulatora rasta tokom perioda skladištenja“ je nova metoda čijom se primenom omogućava kontrolisanje procesa prorastanja crnog luka tokom i nakon perioda skladištenja kako bi se smanjili gubici i održao visok kvalitet lukovica koje zahteva savremeno tržište. Novom metodom definisani su: - parametri za praćenje prorastanja lukovica: broj, masa i dužina spoljašnjih klica; broj, masa i dužina unutrašnjih klica; broj proraslih lukovica i masa lukovica; - intervali za praćenje definisanih parametra; - skala za ocenu porasta unutrašnjih klica. Primenom ove nove metode se obezbeđuje praćenje i kontrolisanje procesa prorastanja lukovica i pravovremena identifikacija crnog luka koji je na samom početku procesa prorastanja. Na ovaj način utvrđuju se palete koje treba prve izneti iz skladišta i plasirati na tržište pre nego što kvalitet počne da opada. Takođe, primenom ove nove metode daje se značajan doprinos celokupnom unapređenju redovne tehnologije skladištenja crnog luka, čime je omogućeno povećanje konkurentnosti firme Rit Agro d.o.o. iz Šida, kao i drugih potencijalnih korisnika ove nove metode.

Implementation of plant extracts that are rich in phytochemicals and have the allelopathic potential for weed management could help reduce the use of chemical herbicides. The present study investigated the herbicidal potential of walnut (Juglans regia L.) leaf extract (WLE) against two weeds, Amaranthus retroflexus L. and Chenopodium album L., by testing in vitro their seed germination and seedling growth, and then evaluated in vivo the oxidative stress of potted plants. The effects of the walnut leaf extract were also tested on maize (Zea mays L.) to eliminate possible negative impacts on a cultivated plant. Total phenolic acids and total flavonoid content in the extract were determined in prior bioassays, followed by separation and analysis of flavonoids and phenolic acids by high-performance liquid chromatography (HPLC). Phytochemical analysis revealed that the obtained extract was notably rich in phenolic compounds, while HPLC analysis confirmed the presence of (+)-catechin, luteolin, myricetin, rutin, (-)-epicatechin, genistin, protocatechuic acid, and caffeic acid as major extract components. The results obtained in bioassays revealed a significant negative impact of the walnut leaf extract on germination and seedling growth of the tested weeds, as well as significant oxidative stress in weeds grown in pots. Although it affected the maize seedling growth in vitro similar to the tested weeds, maize germination was less sensitive to treatment, and the extract did not have a significant negative impact in terms of oxidative stress in maize plants grown in pots. The findings show that walnut leaf extract may have a promising role in replacing chemical herbicides in maize.

After an outbreak of cobweb disease of cultivated button mushroom in Serbia in 2003, the isolated fungal pathogen was initially identified as Cladobotryum dendroides (teleomorph Hypomyces rosellus) based on morpho-physiological traits. Molecular analysis indicated re-classification of two strains (isolated in 2004 and 2007) as Cladobotryum mycophilum (teleomorph Hypomyces odoratus). However, subsequent analysis of further five strains (isolated over the period 2003-2010) within the frames of the present study, also confirmed their identification as the exclusive cobweb causal agent C. mycophilum. After artificial inoculation, the symptoms observed on harvested and growing mushrooms were consistent with the appearance of cobweb disease. Pathogen sensitivity to fungicides was estimated by probit analyses. Fungicide susceptibility tests showed that C. mycophilum strains were highly sensitive both to prochloraz (ED50 lt 0.087 mu g mL(-1)) and the newly introduced metrafenone (ED50 lt 0.15 mu g mL(-1)). Furthermore, the growth of all examined strains of C. mycophilum was significantly inhibited by the indigenous actinobacterial strain Streptomyces flavovirens A06. A dual culture assay showed after 72 h that the percentage of radial growth inhibition of the pathogen ranged from 22.38 to 55.73%. Our findings suggest that the antagonistic S. flavovirens A06 might be a potential candidate for controlling the cobweb disease of cultivated button mushroom.

Crni luk (Allium cepa L.) je zeljasta, dvogodišnja, monokotiledona povrtarska biljka koja se gaji u čitavom svetu, a najviše na području Azije. U Republici Srbiji se gaji na oko 20.000 ha, sa prosečnim prinosima od 6-8 t/ha. Visok sadržaj proteina, ugljenih-hidrata, etarskih ulja, vitamina i mineralih materija, čini da crni luk ima visoku hranljivu vrednost i veoma raznovrsnu i učestalu upotrebu u ljudskoj ishrani, kao i u farmaceutskoj i kozmetičkoj industriji. Nakon vađenja, neophodno je da se lukovice dobro uskladište. Svrha skladištenja je produženje perioda čuvanja do plasmana na tržište i smanjenje gubitaka ostvarenih prinosa. Jedan od najvećih problema koji se javlja tokom perioda skladištenja crnog luka, a koji ograničava period čuvanja i smanjuje kvalitet, je proklijavanje, odnosno klijanje lukovica. Za praćenje klijanja crnog luka u skladištima nema zvanične metode, te su ogledi u ovom radu izvedeni prema metodi za sprečavanje klijanja krtola uskladištenog krompira (OEPP/EPPO 1/164 (3)). Cilj rada je bio da se navedena metoda prilagodi ispitivanjima u crnom luku, kao i da se ispita efikasnost malein-hidrazida (MH) u sprečavanju klijanja crnog luka tokom perioda skladištenja. Ispitivanja uticaja MH i uslova skladištenja na proklijavanje lukovica crnog luka izvedena su tokom 2018/19. i 2019/20. godine. Malein hidrazid je primenjen kao komercijalni preparat Royal MH 30 u količini 12,5 l/ha 21 dan pre vađenja lukovica. Ogledi su postavljeni na lokalitetu u Gospođincima, a nakon vađenja lukovice su prenete u skladište firme Rit Agro d.o.o. u Kukujevcima.Tokom perioda skladištenja svakih mesec dana (I – VIII ocena) je merena masa lukovica i praćen broj isklijalih lukovica, masa i dužina klica, a na kraju ogleda je izračunat gubitak mase lukovica u odnosu na masu u trenutku skladištenja. Za utvrđivanje proklijavanja lukovica nakon iznošenja iz skladišta i izlaganja temperaturi 18-20oC, tokom 6 nedelja je na svakih 10 dana praćen broj ukovica sa vidljivim klicama.

Cilj ovog rada je bio da se ispita alelopatski potencijal biljnog ekstrakta izolovanog iz zelenih plodova oraha na klijanje i rani porast semena dve korovske vrste (Amaranthus retroflexus i Chenopodium album), kao i fitotoksični efekat na klijanje i rani porast semena kukuruza Zea mays. Pored toga, cilj je bio i da se uradi analiza biljnog ekstrakta i procena njegove antioksidativne aktivnosti. Antioksidativna aktivnost biljnog ekstrakta određivana je kroz sposobnost neutralizacije DPPH (2,2-difenil-1-pikrilhidrazil) radikala i ispitivanjem sposobnosti redukcije gvožđa FRAP metodom. Inhibicija merenih parametara (ukupna klijavost i dužina klijanaca) se proporcionalno smanjivala sa smanjenjem koncentracije rastvora biljnog ekstrakta izolovanog iz zelenih plodova oraha. Takođe, parametar dužina klijanaca je ispoljio veću osetljivost u odnosu na parametar ukupne klijavosti semena kod obe korovske vrste. Iako, dobijeni rezultati iz biotesta sa semenima pokazuju visok inhibitorni efekat na klijanje i rani porast obe korovske vrste, ujedno ukazuju i na fitotoksične efekte kod ranog porasta semena gajene vrste Z. mays. Buduća istraživanja će se fokusirati na HPLC analizu biljnog ekstrakta izolovanog iz zelenih plodova oraha i njegovog alelopatskog svojstva na rani porast biljaka testiranih vrsta., The aim of this study was to test the allelopathic effects of the plant extracts isolated from immature walnut fruits on the germination and early seedling growth of two weed species (Amaranthus retroflexus and Chenopodium album), and its phytotoxic effects on the germination and early seed growth of maize, Zea mays. Additionally, the goals was to also conduct an analysis of the plant extracts and determine its antioxidant properties. Antioxidant activity of the plant extracts were determined via its ability to neutralize DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and by testing their potential for iron reduction using the FRAP method. The inhibition of the measured parameters (total germination and seedling length) decreased proportionally, with the reduction of concentrations of plant extracts isolated from immature walnut fruits. Also, the seedling length parameter has shown greater sensitivity when compared with the parameters of total seed germination in both weed species. Even though the results of both biotests with seeds show a high inhibitory effect on the germination and early growth of the tested weed species, they also point to phytotoxicity in early growth of Z. mays seeds. Future research will be focused on the HPLC analysis of the plant extracts isolated from immature walnut fruits and their allelopathic effects on the early growth of plants of the tested species.

A previous study had confirmed good selective features of a biofungicide based on Bacillus subtilis Ch-13 regarding green mould disease control and increase in white button mushroom (Agaricus bisporus) production. The recommended application rate of the biofungicide in three split doses (30 + 15 + 15 ml m-2) enhanced mushroom yield by 8.41% and control of green mould disease (Trichoderma aggressivum) by 53.57%. A different application procedure of the biofungicide B. subtilis Ch-13 was then further investigated, involving six split doses (6 × 10 ml m-2) of the same total dose of 60 ml which was previously tested in three split doses. The impact of the biofungicide on fruiting body yield and its effectiveness in disease control were evaluated on white button mushroom artificially infected with Trichoderma aggressivum f. europaeum in the experimental mushroom growing room (in vivo). No statistically significant differences in disease control efficacy were found between the fungicide prochloraz (71.08%) and the biofungicide applied either in six split doses (63.05%) or three (58.43%). As for the fungicide/biofungicide positive impact on mushroom production, no statistically significant differences were detected among treatments. The B. subtilis Ch-13-based biofungicide may be applied in three split doses, as well as in six split applications, depending on the watering or picking schedule during mushroom cultivation, as both schemes showed satisfactory efficacy in disease control and positive effects on mushroom yield., Prethodna ispitivanja su potvrdila dobre selektivne osobine biofungicida na bazi Bacillus subtilis Ch-13 u suzbijanju prouzrokovača zelene plesni i povećanju prinosa šampinjona (Agaricus bisporus). Preporučena primena biofungicida u tri podeljene doze primene (30 + 15 + 15 ml m-2) povećala je prinos šampinjona 8,41 % i ispoljila efiksanost u suzbijanju Trichoderma aggressivum, prouzrokovača zelene plesni 57%. Biofungicid na bazi B. subtilis Ch-13 je dalje testiran da bi se ispitao drugi način njegove primene, u šest podeljenih doza (6 × 10 ml m-2) u istoj ukupnoj količini od 60 ml kao kod prethodne doze primene u tri tretmana. Uticaj na prinos i efikasnost u suzbijanju prouzrokovača zelene plesni je ispitana veštačkom inokulacijom patogena Trichoderma aggressivum f. europaeum u oglednom gajilištu šampinjona (in vivo). Nisu utvrđene statistički značajne razlike u efikasnosti između fungicida prohloraza (71,08 %), biofungicida primenjenog u šest podeljenih doza (63,05 %) i primenjenog tri puta (58,43 %). U odnosu na uticaj na prinos fungicida i biofungicida, takođe nisu zabeležene statistički značajne razlike u njihovom pozitivnom uticaju. Primena biofungicida na bazi B. subtilis Ch-13 u šest podeljenih doza se može preporučiti jer je ispoljio zadovoljavajući učinak u suzbijanju prouzrokovača zelene plesni i nije pokazao negativan uticaj na prinos šampinjona.

Cilj ovog rada je bio da se in vitro ispita bioherbicidni uticaj eteričnog ulja mirođije (Anethum graveolens) na klijanje i rani porast klijanaca dve parazitne cvetnice iz roda Cuscuta (Cuscuta campestris i C. epithymum), kao i fitotoksični uticaj na klijanje i rani porast klijanaca semena domaćina (lucerka i crvena detelina). Etarsko ulje iz suvih listova mirođije dobijeno je hidrodestilacijom u Klevendžer aparaturi. Identifikacija pojedinačnih komponenti testiranog etarskog ulja je urađena na gasno-masenom spektrometru (GC/MS, Varian CP-3800/Saturn 2200). Naklijavanje semena je rađeno u Petri šoljama sa po 25 dezinfikovanih semena u koje se nanosilo po 5 ml rastvora eteričnog ulja u različitim koncentracijama. Rastvori su pripremani sa 0,5 ml eteričnog ulja i Tween 20 u odnosu 1:1, rastvorenih u dejonizovanoj destilovanoj vodi da bi se dobio rastvor od 1%. Ostale koncentarcije (0,01%, 0,1% i 0,5% v v-1) su dobijene razblaživanjem. Dejonizovana voda sa rastvorom Tween 20 od 1,0% korišćena je kao kontrola. Petri šolje su potom odložene u uslove mraka u inkubatoru na temperaturu od 28±1°C. Prebrojavanje proklijalih semena rađeno je svakodnevno u trajanju od 6 dana, dok su poslednjeg dana ogleda izmerene i dužine klijanaca. Hemijskom analizom eteričnog ulja izolovanog iz listova mirođije je dobijeno da su karvon (56,4 %), p-cimen (22,8 %) i -felandren (14 %) dominantne komponente. Rezultati biotesta sa semenima su pokazali inhibitorni uticaj eteričnog ulja izolovanog iz listova mirođije pri različitim koncentracijama na klijavost i rani porast klijanca obe vrste roda Cuscuta. Naime, inhibicija klijanja semena C. campestris se kretala od 67% (rastvor konc. 0,01%) do 93,75% (rastvor konc. 0,5% i 1%), dok je kod semena C. epithymum inhibicija na dve najviše koncentracije (0,5% i 1%) bila 100%, a na nižim 80%, odnosno 67% (0,1% i 0,01%). Sličan inhibitorni uticaj je zabeležen i za parametar dužina klijanaca. Pored ovoga, u rezultatima biotesta su zabeleženi značajni fito

We studied the main phenolic components of velvetleaf (Abutilon theophrasti), common ragweed (Ambrosia artemisiifolia) and common cocklebur (Xanthium strumarium) aqueous extracts and evaluated their phytotoxicity to germinating seeds and seedling growth of lettuce and tomato. A total of 13 phenolic compounds were identified in aqueous extracts. The highest total phenolic content was found in velvetleaf leaves, followed by common ragweed leaves and common cocklebur stems. Caffeoyl quinic acids were the most abundant phenolics in these three weeds, while common ragweed and velvetleaf leaves were also rich in p-coumaric acid and rutin, respectively. Other phenolic compounds were present in moderate quantities in the stems and leaves of the tested weeds. The weed extracts at 50 % concentration or higher significantly inhibited the seed germination and early seedling growth of lettuce and tomato. The leaf aqueous extracts were more phytotoxic to lettuce and tomato than stem aqueous extracts. The leaf aqueous extract of common ragweed had the strongest inhibitory effects on lettuce, while the leaf aqueous extract of velvetleaf was most inhibitory to tomato. The aqueous extracts of common cocklebur were less inhibitory to lettuce and tomato.

U laboratorijskim uslovima ispitivan je uticaj 10 sojeva aktinobakterija na klijanje semena i porast klijanaca kukuruza i divljeg sirka. Primarni inokulumi sojeva aktinobakterija su zasejani na tečnu skrobno-kazeinsku podlogu i stavljeni su na mućkanje na tresilicu 7 dana. U sterilne Petri kutije odbrojano je po 10 semena obe biljne vrste i dodato po 5ml filtrirane suspenzije aktinobakterija koje su odložene u termostat (26°C). Posle 7 dana mereni su dužina korenka i stabaoca, kao i broj isklijalih semena. Suspenzije svih 10 ispitivanih sojeva aktinobakterija imale su uticaja na klijanje semena i porast klijanaca kukuruza i sirka. Soj A18 pokazao se kao najbolji kandidat za dalja ispitivanja jer su utvrđene inhibicije za kukuruz bile manje od 35%, dok su za sirak bile veće od 90%., In laboratory conditions 10 actinobacteria strains were screened for germination and seedling growth of maize and Johnson grass. Primary inoculum of actiobacteria were grown in starch casein broth for 7 days in a shaking incubator. Ten seeds from both species, were placed inside sterile Petri dishes and moinsted with 5ml of the culture filtrate of actinobacteria and incubated at 26°C. After the period of 7 days, the percentage of germination was calculated and coleoptile and radicle length were measured. Suspensions of all 10 actinobacteria strains had an effect on seed germination and early seedling growth of maize and Johnson grass. The A18 strain proved to be the best candidate for further testing because the inhibitions for maize were less than 35% and for Johnson grass they were higher than 90%.

Uticaj metribuzina na zemljišne mikroorganizme, njihovu enzimatsku aktivnost kao i nivo ostataka ovog herbicida u velikoj meri zavisi od tipa zemljišta i njihovih fizičko-hemijskih karakteristika. Postavljen je laboratorijski ogled da bi se utvrdio uticaj metribuzina na različite grupe mikroorganizama i dehidrogenaznu aktivnost u ilovači i peskuši. Takođe je određen nivo ostatka metribuzina u ovim zemljištima. Ispitivane su sledeće koncentracije. 12,0, 24,0, 120,0 i 1200,0 mg a.s. kg-1 zemljišta. Uzorci su uzeti 3,7, 14,30 i 45 dana nakon primene metribuzina. Uticaj metribuzina na ukupan broj bakterija je bio inibitornog karaktera kod oba tipa zemljišta, i kretao se od 6,9% za ilovaču do 7,9% za peskušu. Aktinomicete su u prvih četrnaest dana nakon primene metribuzina imale smanjenu brojnost za 15,6% u ilovači i 8,1 u peskuši. Međutim, od tridesetog dana broj se povećao ili bio na nivou kontrole. Broj gljiva u ilovači je bio povećan za 6,0% sedam dana nakon primene dve najveće koncentracije. U peskuši je brojnost ove grupe bila značajno smanjena za 29%. Primena metribuzina je značajno smanjila aktivnost enzima dehidrogenaza kod oba zemljišta. Jedino je najveća koncentracija u peskuši ispoljila stimulativan efekat (33,2 %). Rezultati degradacije su pokazali da su izmerene količine metribuzina opale sa vremenom kod oba tipa zemljišta i pri primeni sve četiri koncentracije. Može se zaključiti da je ekstrahovana količina aktivne materije metribuzina za sve primenjene koncentracije veća za zemljište tipa peskuša. Ovo ukazuje da je zbog većeg sadržaj organske mase i gline, zemljište tipa ilovače ispoljilo bolje sorpcione sposobnosti., The effect of metribuzin on soil microorganisms and their enzymatic activity, as well as the amount of metribuzin residues, greatly depend on the type of soil and its physico-chemical properties. A laboratory experiment was set up to determine the effects of metribuzin on different groups of microorganisms and dehydrogenase activity in loamy and sandy soils. The amounts of metribuzin residues in those soils were also determined. The following concentrations were tested: 12.0, 24.0, 120.0 and 1200.0 mg A.I. kg-1 soil. Samples were collected 3, 7, 14, 30 and 45 days after metribuzin application. Metribuzin acted inhibitively on total bacteria counts in both types of soil: 6.9% in loamy and 7.9% in sandy soils. Actinomycetes counts decreased over the first 14 days after metribuzin treatment by 15.6% in loamy and 8.1% in sandy soil. However, starting with the 30th post-treatment day, their number either increased or remained at the control level. Fungi counts increased by 6.0% seven days after the application of the two highest concentrations. In sandy soil, fungi counts were significantly reduced by 29%. Metribuzin treatment significantly reduced the activity of dehydrogenase enzyme in both types of soil. Only the highest test concentration applied to the sandy soil showed a stimulating effect (33.2 %). Degradation data showed that the measured amounts of metribuzin decreased over time in both types of soil at all four test concentrations. The results showed that the extracted amounts of metribuzin active ingredient at all its test concentrations were greater in the sandy type of soil. Loamy soil was shown to have a better sorption capacity due to its higher contents of organic matter and clay.

The purpose of the present investigation was to determine the effect of parasitism by Cuscuta campestris on the yield and composition of the essential oil of fennel (Foeniculum vulgare). The experiment included the following variants: N - noninfested fennel plants (control); I - infested fennel plants. The essential oils of fennel were obtained by hydrodistillation in a Clevenger apparatus. Chemical characterization of the tested essential oils was performed by gas chromatography (GC) using two types of detectors (flame ionization detector [FID] and mass spectrometer [MS]). The yields of the obtained essential oils (noninfested and infested fennel plants) were 5.6% and 5.8%, respectively. Analyses showed that the main components of the essential oil isolated from noninfested fennel plants were trans-anethole (67.0%) and fenchone (26.5%). The content of trans-anethole in the essential oil isolated from infested fennel plants (38.5%) was significantly reduced, while the content of fenchone was higher (34.5%). Methyl chavicol (19.6%) was an additional dominant component in the essential oil of infested fennel plants.

As primary producers, macrophytes in water bodies represent irreplaceable part of aquatic environment. Negative effects of herbicides in non-target macrophytes, as well as their detection in surface waterbodies have been repeatedly found. One of the most frequently used aquatic macrophytes for pesticide effects assessment is Lemna sp. Pethoxamid is chloroacetamide herbicide, cell division inhibitor. In Serbia it is used as preemergent herbicide for broadleaf and grass weeds control in maize crops. The aim of this study was to evaluate effects of pethoxamid on non-target aquatic macrophytes. For this purpose, the estimation of growth parameters and chlorophyll content in Lemna minor after exposure to series of concentration was performed. Results obtained in this investigation indicated that pethoxamid is toxic for non-target aquatic macrophytes with potential to cause long term adverse effects in the environment.

Tokom 2020. i 2021. godine izvedena su ispitivanja efikasnosti karfentrazon-etila u desikaciji soje. Ogledi su postavljeni na lokalitetima Novi Karlovci i Putinci, po slučajnom blok sistemu, u četiri ponavljanja. Karfentrazon-etil je primenjen kao komercijalni preparat Affinity Plus, u količini 1 L ha-1, a kao standardi korišćeni su dikvat i glufosinat-amonijum, takođe, kao komercijalni preparati u preporučenim količina primene. Svi tretmani su primenjeni u fazi prirodnog dozrevanja useva, kada su biljke odbacile oko 30% listova. Ocena efikasnosti urađena je tri i sedam dana posle primene (DPP) preparata, a praćeni su i mereni parametri: boja stabla, boja listova, boja mahuna, masa stabla (g), masa mahune (g). Karfentrazon-etil, kao preparat Affinity Plus u količini 1 L ha-1 dovodi do sušenja stabla, listova i mahuna soje. Pod uticajem karfentrazon-etila, u zavisnosti od godine ispitivanja i lokaliteta, masa stabla je smanjena za 31-55% tri DPP, odnosno 43-56% sedam DPP, dok je masa mahune smanjena za 22-36% tri DPP, odnosno 27-39% sedam DPP. U istim uslovima dikvat i glufosinat-amonijum ostvarili su inhibicije veće za 1-18% u poređenju sa karfentrazon-etilom. Rezultati ovih istraživanja su pokazali da se karfentrazon-etil može koristiti za desikciju soji, ali da proizvođači moraju računati na nižu efikasnost u poređenju sa dikvatom i glufosinat-amonijumom., Efficacy of carfentrazone-ethyl for soybean desiccation was tested during the vegetation seasons of 2020 and 2021. The field trials were set up in Novi Karlovci and Putinci field sites, following a randomized block design, in four replicates. Carfentrazone-ethyl was applied as a commercial product Affinity Plus, in the dose of 1 L ha-1, while diquat and glufosinateammonium were used as standards and commercial products in their recommended application doses. All treatments were conducted in the stage of natural crop ripening, when 30% of the leaves had fallen. Efficacy evaluation was done 3 and 7 days after application (DAA), when the following parameters were observed: stem color, leaf color, pod color, stem mass (g), and pod mass (g). Carfentrazone-ethyl, as Affinity Plus, in quantities of 1 L/ha led to the desiccation of soybean stems, leaves and pods. Carfentrazone-ethyl, depending on the study year and field site, has resulted in a 31-55% stem mass reduction 3 DAA and 43-56% 7 DAA. Pods mass was reduced by 22-36% 3DAA and 27-39% 7DAA. Under the same conditions, diquat and glufosinate-ammonium reduced the observed soybean parameters by 1-18% more, when compared with carfentrazone-ethyl. Therefore, the results of this study show that carfentrazone-ethyl can be used in soybean desiccation, but that soybean producers must be aware of its lower efficacy, when compared with diquat and glufosinate-ammonium.

Aktinobakterije su jedna od najšire rasprostranjenih grupa mikroorganizama u prirodi koje su u velikom broju prisutne i u obrađenim i u neobrađenim zemljištima. Aktivno učestvuju u biodegradaciji zemljišta i formiranju humusa i predstavljaju izvor mnogobrojnih sekundarnih metabolita koji imaju veliki farmakološki, alelopatski i komercijalni značaj. Upravo taj alelopatski potencijal aktinobakterija za stvaranje bioherbicidnih metabolita svrstava ih u grupu dobrih kandidata za biološku kontrolu korova. Cilj ovog rada bio je da se u laboratorijskim uslovima ispita uticaj različitih izolata zemljišnih aktinobakterija na klijanje semena i porast klijanaca kukuruza i divljeng sirka (Sorghum halepense (L.) Pers.) kao jednog od najčešćih korova u ovom usevu. U ogledu su korišćena semena kukuruza (hibrid NS3022, Institut za ratarstvo i povrtarstvo Novi Sad) i semena divljeg sirka sakupljena na lokalitetu Galenika-Zemun, tokom oktobra meseca 2019. godine. Testirana je herbicidna aktivnost 10 izolata zemljišnih aktinobakterija (A01, A03, A06, A07, A10, A11, A17, A18, NOV3 i NOV4) iz kolekcije Instituta za pesticide i zaštitu životne sredine, Beograd (Laboratorija za herbologiju). Primarni inokulumi aktinobakterija su zasejani na tečnu skrobno-kazeinsku podlogu i stavljeni su na mućkanje na tresilicu 8 dana. U sterilne Petri kutije odbrojano je po 10 semena obe biljne vrste i dodato po 5 ml filtrirane suspenzije aktinobakterija, a zatim su odložene u termostat (26°C). Posle 6 dana mereni su dužina korenka i stabaoca kao i broj isklijalih semena. Dobijeni rezultati pokazali su da je svih 10 izolata aktinobakterija imalo značajan alelopatski uticaj na klijanje semena i porast klijanaca kukuruza i divljeg sirka. Najveći inhibitorni uticaj na klijanje semena i porast klijanaca imao je izolat NOV3, sa preko 52% za kukuruz i preko 80% za divlji sirak. Sa druge strane, izolat A18 pokazao se kao najbolji kandidat za dalja ispitivanja, jer su utvrđene inhibicije porasta klijanaca za kuk

Thirty-five actinobacterial isolates, obtained from button mushroom (Agaricus bisporus) substrates (i.e., compost in different phases of composting, black peat or casing layer) in Serbia in 2014-2016 were tested in vitro against the causal agents of green mold in cultivated mushroom. Out of six most promising isolates, A06 induced 42.4% in vitro growth inhibition of Trichoderma harzianum T54, and 27.6% inhibition of T. aggressivum f. europaeum T77. The novel strain A06 was identified as Streptomyces flavovirens based on macroscopic and cultural characteristics and 16S rDNA sequence and used in mushroom growing room experiments. Actinobacteria had no negative influence on mycelial growth of the cultivated mushroom in compost in situ. Isolate S. flavovirens A06 enhanced mushroom yield significantly, up to 31.5%. The A06 isolate was more efficient in enhancing yield after inoculation with the compost mold T. aggressivum (26.1%), compared to casing mold T. harzianum (8%). Considering disease incidence, actinobacteria significantly prevented green mold in compost caused by T. aggressivum (6.8%). However, fungicide prochloraz-Mn had a more significant role in reducing symptoms of casing mold, T. harzianum, in comparison with actinobacteria (24.2 and 11.8%, respectively). No significant differences between efficacies of S. flavovirens A06 and the fungicide prochloraz-Mn against T. aggressivum were revealed. These results imply that S. flavovirens A06 can be used to increase mushroom yield and contribute to disease control against the aggressive compost green mold disease caused by Trichoderma aggressivum.

Sudbina herbicida primenjenih u poljoprivrednim ekosistemima regulisana je procesima transfera i degradacije i njihovom interakcijom sa zemljišnim mikroorganizmima. U tim procesima fizičko-hemijski sastav, količina i vreme primene herbicida, kao i osobine zemljišta su od primarnog značaja. Takođe, biogenost zemljišta je značajan pokazatelj promena u mikrobiološkoj i biohemijskoj aktivnosti zemljišta koje nastaju posle primene herbicida. Imajući to u vidu, za cilj u ovom radu je postavljeno ispitivanje uticaja metribuzina na proteolitske mikroorganizme i enzim proteaze u zemljištima koja se značajno razlikuju po svojim karakteristikama. Ogled je postavljen u laboratorijskim uslovima na zemljištima teksturnih klasa glinovita ilovača i peskuša. Metribuzin (4-amino-6-terc-butil-3-metiltio-1,2,4-triazin-5-(4H)-on), preparat Sencor-WG, primenjen je u koncentracijama 12,0; 24,0 i 120,0 mg/kg zemljišta. Koncentracije su izabrane tako da najniža odgovara količini koja se preporučuje za primenu, druga je duplo veća, a treća deset puta veća. Uzorci za analizu uzimani su 3, 7, 14, 30 i 45 dana posle primene metribuzina. Broj proteolitskih mikroorganizama je određen na hranljivom agaru sa želatinom, a aktvnost enzima proteaza praćena je titrometrijski na želatinoznom supstratu. U kontrolnim varijantama ogleda može se uočiti uticaj fizičko-hemijskih i strukturnih osobina zemljišta na brojnost proteolitskih mikroorganizama i aktivnost enzima proteaze. U ilovači je taj broj iznosio 7,25x104 CFU/g, a aktivnost enzima proteaze bila 25,15 žel.jed./g zemljišta, dok je u preskuši broj proteolitskih mikroorganizama bio 4,83x104CFU/g, a enzimatska aktivnost je iznosila 17,75 žel. jed./g zemljišta. U ilovači primena metribuzina nije izazvala značajne promene u brojnosti proteolitičkih mikroorganizama. Međutim, primena metribuzina je imala inhibitorni efekat na proteolitičke mikroorganizme u peskuši i izazvala je značajno smanjenje njihove brojnosti četrnaest dana nakon primene. Tada je zab

The effects of the nicosulfuron and glyphosate herbicides on microbial activity in two soils with different physical and chemical properties (loam and sand) were investigated. Nicosulfuron was applied at the rates of 0.3, 0.6, 3.0 and 30.0 mg kg(-1) soil and glyphosate at 32.6, 65.2, 326.0 and 3260.0 mg kg(-1) soil in the laboratory. Changes in dehydrogenase and urease activity, as well as in microbial biomass carbon, were examined. Samples for the analysis were collected at 3, 7, 14, 30 and 45 days after herbicide application. The results showed that the effects of nicosulfuron and glyphosate depended on treatment rate, duration of activity, test parameters and soil types. In general, application of the herbicides significantly increased the activity of dehydrogenase and urease. Nicosulfuron had a stimulating activity on microbial biomass carbon in loam, while both herbicides demonstrated negative effects on the parameter in the sandy soil.

Tekstura zemljišta i druge fizičke i hemijske karakteristike zemljišta predstavljaju važne faktore koji utiču na zadržavanje herbicida u zemljišnim ekosistemima. Postavljen je laboratorijski ogled da bi se procenio odgovor proteolitičkih mikroorganizama i aktivnosti proteaze na primenu metribuzina u različitim tipovima zemljišta (ilovača i peskuša). Ispitivane su sledeće koncentracije. 12,0, 24,0; 120,0 i 1200,0 mg a.s. kg-1zemljišta. Uzorci su uzeti 7, 14 i 30 dana nakon primene metribuzina. Metribuzin nije uticao na broj proteolitičkih mikroorganizama u ilovači. U peskuši broj je smanjen za 26,7% sedam dana nakon primene najveće koncentracije. Aktivnost proteaze bila je smanjena u oba tipa zemljišta sedmog i četrnaestog dana, u ilovači procenat smanjenja je iznosio 21% a u peskuši 29,9%. Statistička analiza podataka je pokazala da je korelacioni odnos između ispitivanih parametara bio pozitivan za oba tipa zemljišta (za ilovaču r2=1; za peskušu r2=0,81). Ispitivanja su pokazala da je metribuzin imao prolazni uticaj na mikrobiološku populaciju i enzimatsku aktivnost i zavisio je od tipa zemljišta., Soil texture and other physical and chemical characteristics of soil are important factors influencing the retention of herbicides in soil ecosystems. A laboratory experiment was conducted to estimate the response of proteolytic microorganisms to applications of metribuzin in different types of soil (loamy and sandy) in terms of density and protease activity. The following concentrations were tested: 12.0, 24.0, 120.0 and 1200.0 mg a.i.kg-1 soil. Samples were collected 7,14 and 30 days after treatment with metribuzin. Metribuzin did not affect the number of proteolytic microorganisms in loamy soil. In sandy soil, their number was reduced 26.7% by the highest concentration 7 days after application. Protease activity was reduced in both types of soil on the 7th and 14th day and the percentage of reduction was 21% for loamy soil and 29.9% for sandy soil. Statistical analysis of data showed that the correlation between test parameters was positive in both types of soil (r2=1 for loamy soil, and r2=0.81 for sandy soil). The study shows that metribuzin causes a passable impact on microbial population and enzymatic activity which depends on the type of soil.

Studies of adsorption and desorption of pesticides by soils are important for understanding and predicting their fate and transmission in the environment. Considering the agricultural and environmental relevance of clomazone, its sorption-desorption behaviour was studied in two widespread Serbian agricultural soil types named Regosol and Chernozem. Both phenomena are well-described by the Freundlich equation, which shows that clomazone is generally sorbed more to organic matter than to the mineral soil fractions. Chernozem, a soil containing more of both organic matter and clay, was found to bind more, and desorb less herbicide, than Regosol. Higher desorption hysteresis obtained for Chernozem could be attributed to its larger number of high-energy sorption sites, compared to Regosol. In both soils, the hysteresis effect increases with the rise of initial clomazone concentration in the soil-water system, while the percentage of desorbed amount during successive desorption cycles decreases. The presented adsorption-desorption study shows that soil composition plays an important role in clomazone behaviour and fate in the environment, and a significantly reduced probability of contamination of both the deeper soil layers and groundwater may be expected when this herbicide is found in humus-rich soils.

Peppermint (Mentha piperita L.) and chamomile (Chamomilla recutita (L.) Rausch.) are aromatic plants with considerable economic value. These plants and their essential oils are used in medicine, cosmetics, and the food industry. One of the main limiting factors in peppermint and chamomile commercial cultivation is weed competition since weeds are able to decrease both oil amount and biomass yield. The purpose of the present study was to determine the effect of parasitism by field dodder (Cuscuta campestris Yunck.) on peppermint and chamomile dry weight and their essential oil yield and composition. Essential oils from both noninfested and infested peppermint and chamomile plants were obtained by hydrodistillation and characterized chemically by gas chromatography (GC) coupled with mass spectrometry (MS). The amount of dry matter accumulated by peppermint and chamomile plants infested by field dodder was lower (25% and 63%, respectively) compared to noninfested plants. Essential oil yield increased for peppermint (3.87% (v/w) and 3.63% (v/w)), but decreased for chamomile (0.2% (v/w) and 0.5% (v/w)) both from infested and noninfested plants, respectively. The oil composition profile significantly differed in terms of content. In peppermint plants, field dodder infestation increased menthone content by 23%, and decreased the content of both menthol by 11% and pulegone by 67%. Furthermore, delta-cadinene was detected only in oil extracted from infested peppermint plants. Compared to peppermint, chamomile plants were significantly more affected by field dodder in terms of essential oil yield, as well as oil composition and plant dry weight. In chamomile plants, (E)-dendrolasin was detected in the oil of noninfested plants, and 1,4-dimethyl-7-(1-methylethyl)-azulen-2-ol was detected only in the oil of infested plants.

This study aimed to identify the main components of an essential oil produced from leaves of Ambrosia trifida and to evaluate its potential allelopathic effect on seed germination and seedling growth of lettuce, watermelon, cucumber and tomato. The essential oil was obtained by hydrodistillation and characterized chemically by gas chromatography (GC) coupled with both mass spectrometry (MS) and flame ionization detector (FID). Total 69 compounds were identified, with limonene (20.7 %), bornyl acetate (15.0 %), borneol (14.7 %) and germacrene D (11.6 %) as the major components. The working solutions of the essential oil emulsified with Tween 20 and dissolved in distilled water were prepared at four concentration levels (0.01, 0.1, 0.5 % and 1 %, v/v). The results obtained showed that increase in essential oil concentration leads to decrease in seed germination, as well as shoot and radical length of lettuce, watermelon, cucumber and tomato. The obtained data revealed a highly significant effect (p lt 0.05) between control and 1 % and 0.5 % oil concentrations in all treatments. The essential oil of A. trifida exhibited more powerful phytotoxic effects on lettuce, watermelon and tomato than on cucumber regarding germination and early seedling growth.