The bean weevil Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae) can cause significant losses in production of its primary host common bean Phaseolus vulgaris L. To avoid bean protection with environmentally risky chemical insecticides and provide sustainable and safe production of food, new pest management methods based on natural compounds are investigated. In the present study, we evaluated protective potential of the essential oil (EO) from the common thyme Thymus vulgaris L. applied on bean seeds. We assessed residual contact toxicity of thyme EO and its effects on A. obtectus longevity, oviposition and adult emergence. Furthermore, to elucidate the role of oxidative stress in thyme EO toxicity, we estimated the levels of oxidatively damaged proteins and lipids, as well as the level of thiols which have important role for antioxidant capacity. We found that thyme oil significantly reduced adult survival and longevity, induced oxidative damage to lipids and proteins and depleted protein and non-protein thiols in a concentration-dependent manner. Females appeared to be more tolerant to thyme oil treatment than males. Sublethal EO concentrations affected oxidative stress indices, deterred oviposition and strongly inhibited adult emergence. The results suggest that thyme oil has the potential to be used as an ecofriendly insecticide for A. obtectus control.

The bean weevil (Acanthoscelides obtectus, Say) is a serious pest of stored bean seeds. Bean weevil control relies heavily on the use of synthetic insecticides. In the search for a sustainable alternative, the residual contact toxicity and anti-oviposition activity of thyme (Thymus vulgaris L.), rosemary (Rosmarinus officinalis L.) and basil (Ocimum basilicum L.) essential oils as well as their dominant components (thymol, α-pinene, 1,8-cineole and linalool) were tested against A. obtectus adults. Out of the seven tested botanicals, T. vulgaris oil, thymol and linalool exhibited the highest toxic potential (>90% mortality). Females were less susceptible than males. The insecticidal activity of these botanicals was much greater when they were applied on glass compared to direct application to the bean. All tested botanicals reduced oviposition by bean weevil females. T. vulgaris oil, thymol and α-pinene also deterred bean weevil oviposition, as revealed by a two-choice test. Our research shows that T. vulgaris oil and thymol are promising and sustainable alternatives to synthetic pesticides for protecting stored beans against the bean weevil.

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SummaryA study of in vitro sensitivity of five Alternaria solani isolates to cooper-oxychloride, chlorothalonil, difenoconazole, pyraclostrobin and a biofungicide based on tea tree essential oil was carried out. The isolates were obtained from infected tomato leaves collected from five different locations in Serbia. The tested isolates showed the highest sensitivity to pyraclostrobin with EC 50 values ranging from 0.0014 to 0.0041 µg ml -1 . The EC 50 values of difenoconazole were 0.018-0.037 µg ml -1 , chlorothalonil 2.99-4.54 µg ml -1 , and cooper-oxychloride 13.27-15.63 µg ml -1 . All tested A. solani isolates were the least sensitive to tea tree oil (1323.97-3307.08 μg l -1 ).

Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae), is one of the most important pests of the common bean Phaseolus vulgaris L. Without appropriate management it may cause significant seed loss in storages. In search for means of environmentally safe and effective protection of beans we assessed biological activity of thymol, an oxygenated monoterpene present in essential oils of many aromatic plants. We studied contact toxicity of thymol on bean seeds and its effects on adult longevity and emergence in F1 generation. Furthermore, we determined acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), mixed-function oxidase (MFO), carboxylesterases (CarE) and glutathione S-transferase (GST) activities in response to 24 h exposure of beetles to sublethal and lethal thymol concentrations. Our results showed that thymol decreased adult survival, longevity and percentage of adult emergence. Higher median lethal concentration (LC50) was recorded in females indicating their higher tolerance comparing to males. Overall, activities of SOD, CAT and CarE increased at sublethal and MFO increased at both sublethal and lethal thymol concentrations. On the other hand, GST and AChE activities decreased along with the increase in thymol concentrations from sublethal (1/5 of LC50, 1/2 of LC50) to lethal (LC50). Enzyme responses to the presence of thymol on bean seed were sex-specific. In the control group females had lower CarE and higher SOD, CAT and GST activity than males. In treatment groups, females had much higher CAT activity and much lower CarE activity than males. Our results contribute to deeper understanding of physiological mechanisms underlying thymol toxicity and tolerance which should be taken into account in future formulation of a thymol-based insecticide.

U radu je ispitivan uticaj primene tri različita preparata na prisutnost četiri ekonomski značajne bolesti u usevu nevena, odoljena i krompira . Na nevenu je utvrđivan intenzitet zaraze pepelnice lista (Podosphaera xanthii (Castagne) U . Braun & Shishkoff .), u odoljenu na pegavost lista (Alternaria alternata (Fr . ex Fr .) Keissel), kod krompira na crnu pegavost (Alternaria solani (Ellis & Mart .)) i plamenjaču (Phytophthora infestans (Mont .) de Bary) . Od preparata, primenjen je sintetički preparat "Sekvenca" (a . m . difenokonazol, 250 g/l) u dozi 0,5 l/ha, registrovani biostimulator "Zlatno inje" (đubrivo na bazi stajnjaka) u dozi 3,0 l/ha, mikrobiološki preparat (Bacillus amyloliquefaciens TMF3) u dozi 3,0 l/ha . Četvrta varijanta je bila kontrolna varijanta, odnosno varijanta bez tretmana . Poljski ogledi su izvedeni tokom 2019 . godine na dve lokacije na širem području grada Pančeva . Ogledi su izvedeni po slučajnom blok sistemu u tri ponavljanja . Veličina elementarne parcele bila je 9,0 m 2 (4,5 x 2,0 m) . Kao biljni materijal korišćena je sorta nevena "Domaći oranž", odoljena "Vojvođanski" i krompira "Desire" . Prva ocena intenziteta oboljenja, obavljena je mesec dana nakon tretmana odabranim preparatima, druga je obavljena dve nedelje nakon prve ocene .U usevu nevena najmanji procenat zaraze imale su biljke tretirane sojem Bacillus amyloliquefaciens TMF3, kod odoljena najmanje zaraženih biljaka sa gljivom A. alternata evidentirano je na parcelicama na kojima je primenjen sintetički preparat "Sekvenca", što je bio slučaj i sa crnom pegavosti i plamenjačom krompira . Najslabija efikasnost u suzbijanju pepelnice lista nevena i pegavosti lista odoljena je zabeležena primenom biostimulatora "Zlatno inje", koji je pokazao najveću efikasnost kod plamenjače krompira . Najveći prinos semena nevena (632,7 kg/ ha) imao je tretman sojem Bacillus amyloliquefaciens TMF3, kod odoljena najveći prinos semena zabeležen je pri primeni preparata "Sekvenca" (186,1 kg/ha), dok je kod krompira najveća količina krtola evidentirana sa preparatom "Zlatno inje" (30,83 t/ha) .Ipak, ukoliko se uzmu u obzir agroekološki i agrotehnički aspekt proizvodnje, primenom soja Bacillus amyloliquefaciens TMF3, ostvarena je zadovoljavajuća osnova za različite vrste narednih istraživanja ovog i njemu sličnih preparata, a u cilju unapređenja postojeće proizvodnje lekovitog i ostalih vrsta bilja .

IZVODCilj ovog rada je da se prikažu rezultati proizvodnje višegodišnjeg morača (Foeniculum vulgare Mill.) u izolacionom pojasu organske proizvodnje. Kako se ova biljna vrsta koristi u farmaceutskoj i prehrambenoj industriji, proizvodnja u organskom sistemu gajenja ima poseban značaj. Izolacioni pojas je zasnovan na organskom demo-polju Instituta "Tamiš", na tipu zemljišta, karbonatni černozem. U periodu od 2009. do 2014. godine, vršеnа su fеnоlоškа оsmаtrаnjа, prаćеnо је prisustvо kоrisne entomofaune, a vršeno je i merenje prinosa ploda i etarskog ulja. Ubrzan porast biljaka i rano zatvaranje međurednog prostora, već u trećoj dekadi aprila, vrlo je korisno u organskom sistemu gajenja, jer buјnа nаdzеmnа biоmаsа sprеčаvа rаstеnjе kоrоvа u usevu. Preliminarni rezultati ukazuju na veće prisustvo polinatora, predatora i parazitoida štetnih insekata, što ima poseban značaj u sistemima organske proizvodnje, jer se time može uticati na efikasniju oplodnju, a podstiču se i procesi biokontrole. Starost useva morača i klimatski uslovi uticali su na variranja prinosa po godinama. Prosečan prinos ploda svih godina istaraživanja bio je 1,40 t ha .U godini zasnivanja prinos ploda i ulja bio je najmanji. U narednim godinama prinosi su rasli, tako da je najveći bio u četvrtoj godini, 2,10 t ha -1 ploda i 147,00 kg ha -1 ulja.Ključne reči: organska proizvodnja, izolacioni pojas, morač.