Antagonističko dejstvo saprofitne bakterije serratia liquefaciens prema fitopatogenim gljivama kukuruza i potencijalni biohemijski i molekularni mehanizmi njenog dejstva

The objective of our study was to investigate effect of saprophytic bacterium Serratia liquefaciens derived from sunflower on maize phytopathogenic fungi in vitro and in vivo conditions, as well as, potential biochemical and molecular mechanisms. Obtained results indicate that production of an antibiotic is not a biochemical background of the antagonistic effect. Concurrence advantage of the saprophytic bacterial isolate S. liquefaciens isolated from sunflower, over the parasitic fungus Ph. ambiguum when limited quantities of carbon compounds were used in the joint culture, caused antagonistic effect between these two groups of microorganisms. The de novo synthesis new polypeptides of different molecular weight occurred in interactions with phytopathogenic fungi. The successful activities of isolates of the saprophytic bacterium under in vivo conditions were observed and manifested as lack of disease symptoms (root and stalk rots), and stimulatory effects on the rowth of both, roots and above-ground plant parts. The bacterial isolate S. liquefaciens showed the greatest inhibition rate of colonies growth of fungus Ph. ambiguum under in vivo conditions.Ispitivan je antagonistički efekat saprofitne bakterije Serratia liquefaciens, poreklom iz rizosfere suncokreta na fitopatogene gljive kukuruza u in vitro i in vivo uslovima, kao i potencijalni mehanizmi dejstva na biohemijskom i molekularnom nivou. Uočeno je da bakterijska vrsta S. liquefaciens ne poseduje sposobnost sinteze antibiotika. Antagonistički efekat koji je ova vrsta ispoljila prema Ph.ambiguum pri gajenju na hranljivoj podlozi sa različitim koncentracijama glukoze rezultat je postojanja kompeticijskog odnosa. U interakciji sa fitopatogenim gljivama došlo je do de novo sinteze proteinskih frakcija različitih molekulskih težina. Uspešno delovanje ovog bakterijskog izolata na razvoj fitopatogene gljive Ph. ambiguum ustanovljeno je i u in vivo uslovima, koje se ispoljavalo izostankom simptoma bolesti (truleži korena i stabla) i stimulativnom dejstvu na porast korena kao i nadzemnih delova biljke

Sezonska dinamika Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) u Zemun Polju (Srbija)

The abundance of imagoes of the species Diabrotica virgifera virgifera LeConte 1858 was monitored by the application of yellow sticky traps in a three-factorial trial with long-term continuous cropping of maize in Zemun Polje in 2004. The present study shows the dynamics of eclosion of this species during the July-October period and abundance of imagoes on the field in correlation with application of manure, application of NPK mineral fertilizers, and the amount of crop residues in the soil.Vrsta Diabrotica virgifera virgifera LeConte, oligofagna štetočina, dospela je na naše prostore slučajnom introdukcijom devedesetih godina prošlog veka. Za ovu vrstu svojstveno je da formira ekonomski nivo populacije samo u monokulturi kukuruza. Ogled u kojem je praćena brojnost kukuruzne zlatice je trofaktorijelni zasnovan na eksperimentalnoj parceli Instituta za kukuruz u Zemun Polju 1972. godine. Obuhvatao je 54 varijante, šest kombinacija mineralnih đubriva, tri načina postupanja sa žetvenim ostatcima i tri doze primene stajnjaka. Odabrano je 12 varijanti, praćena je brojnost imaga na žutim lepljivim klopkama marke Pherocon AM. Prva pojava imaga u našim uslovima počinje krajem juna, porast brojnosti događa se u julu, maksimum u julu i avgustu mesecu. Brojnost populacije analizirana je po varijantama na osnovu vremena praćenja i povoljnosti vremenskih uslova za gajenje kukuruza. Tokom tromesečnog perioda (juli, avgust, septembar 2004.) ukupno je uhvaćeno 317 jedinki, brojnost se kretala od nule na početku jula do maksimalnih 76, registrovanih 6. avgusta. Nakon ovog perioda brojnost se znatno smanjila i od početka septembra nije više registrovan ni jedan primerak. Pad brojnosti u drugoj polovini avgusta može se tumačiti migracijom jedinki na susedna polja sa svežom svilom ili polenom u cilju dopunske ishrane. Po varijantama ogleda iznosila je od svega osam u varijanti sa najmanje hraniva, do 52, u varijanti sa najviše hraniva. Možemo konstatovati da je nedostatak vlage u avgustu uslovio brže sazrevanje svile, sušenje zemljišta, masovniju migraciju i skraćenje dužine života imaga, što se odrazilo na pad brojnosti i manjeg broja položenih jaja, što se potvrdilo u 2005. godini

Uticaj insekticidnih i bioinsekticidnih tretmana na intenzitet napada kukuruznog plamenca i prinos kukuruza

During 2008 and 2009, efficacy of insecticidal products, based on thiamethoxam and imidacloprid, were tested. Furthermore, effects of entomophatogenic fungus Beauveria bassiana on the infestation intensity of European corn borer (Ostrinia nubilalis), were established over effects of both, 10 different treatments of maize seed (8 treatments and 2 controls) and the application of the fungal inoculum. Trials were carried out on maize crop under field conditions in accordance with the EPPO method. Results obtained in the studies with the product Cruiser 350 FS (350g l-1 thiamethoxam) applied in the amount of 0.9 l per 100 kg of seed and the products Imidor 600 FS and Gaucho 600FS (600g l-1 imidacloprid) applied in the amount of 0.7 l per 100 kg of seed, point out to satisfactory efficacy in controlling ECB and satisfactory effects on maize yields. The intensity of ECB infestation, expressed in percentages, ranged from 50.1% to 74.1%. The interrelation between average percentages of infested plants and obtained yields in both investigation years (2008-2009) in Zemun Polje was established. Results over treatments indicate that the highest percentages (62.2%) of infested plants were observed in the control variant (K1- Captan). Moreover, as expected, the lowest yield was also recorded in this variant. The treatment with the fungicide Maxim combined with the insecticide Criuser proved to be the most efficient. At the same time, the percentage of infested plants was the lowest in this treatment (53.32%) and the yield was the highest (8.610 t ha-1). The infestation level of maize plants in this treatment was significantly reduced over years of investigation in comparison with remaining treatments. Meteorological factors during the years of investigation, especially unfavourable agroecological conditions in 2009, affected the average yield of maize per hectare. The yield (8.314 t ha-1) recorded in the treatment with the inoculum of B. basssiana was almost equal to the one recorded in the treatment with the product Cruiser (8.610 t ha-1), while it was higher than the yield obtained in the treatment with the products Gaucho (7.506 t ha-1) and Imidor (8.259 t ha-1) combined with the fungicide Maxim. These differences were not statistically significant. Seed treatments with the fungal inoculum were not significantly different in any of observed parameters, except in the seed treatment with Captan. The comparison of data obtained in the two-year studies (2008-2009) under conditions of natural ECB infestation, shows prevalence of plants with damages of leaves (type H2) and tassels (type M3-4), which is indicated with the average score of 2.43. According to the average scores, it can be concluded that ECB infestation did not result in damages that would have significantly affected maize yield. In order to establish significance of certain observed parameters, they were compared and their correlations were determined. The greatest negative correlation with the 0.05 probability level (r= -0.96533) was established between the plant damage score and the recorded yield. Since recorded value of coefficients of correlation was approximately 1, it can be stated that the complete functional linear dependence existed among variables. Achieved results show efficiency of insecticides based on thiamethoxam and imidacloprid in the regulation of the infestation level in maize and also point to negative effects of the fungus B. bassiana on entomofauna of maize and its mycoinsecticide activity that could find an application in biocontrol of insect pests of maize.Tokom 2008. i 2009. godine, ispitana je efikasnost insekticidnih preparata, na bazi tiametoksama i imidokloprida i entomopatogeno dejstvo Beauveria bassiana na intenzitet napada kukuruznog plamenca (Ostrinia nubilalis) i njihovog uticaja na prinos srednjestasnog hibrida kukuruza. Ispitivanja su izvedena u skladu sa EPPO metodom u poljskim uslovima u usevu kukuruza. Ostvareni rezultati ispitivanog preparata Cruiser 350 FS (350g l-1 tiametoksama) koji je primenjen u količini 0,9 l na 100 kg semena i preparata Imidor 600 FS i Gaucho 600FS (600g l-1 imidokloprida) primenenjenih u količini 0,7 l na 100 kg semena, ukazuju na zadovoljavajuću efikasnost u suzbijanju kukuruznog plamenca i visinu prinosa kukuruza

Populacioni nivo imaga kukuruzne zlatice u periodu od 2005-2009 godine

Western corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte) is one of the most important and potentially most dangerous pests of maize. Since its occurrence in Serbia in 1992, it has been present in almost all areas under maize cultivation. Alongside with all preventive measures, first of all, the crop rotation, which is considered the most economic one, a great attention has been paid to the forecast of the pest occurrence based on the flight dynamics and the population level. The flight dynamics, sex dominance, variations in the population level depending on the trap types and climate factors were observed on two locations: Crepaja in three-year continuous cropping (2005-2007) and in the experimental field of the Maize Research Institute, Zemun Polje in the duration of five years (2005-2009). According to the flight dynamics of WCR adults, the highest population level of this pest was observed in 2005, while the comparison of the number of adults over locations showed greater abundance of the pest in Crepaja than in Zemun Polje, which was attributed to extreme favourability of agro-ecological conditions on this location for the WCR development. The 2008-2009 period was characterised by the reduced number of WCR, which coincided with the extremely arid conditions that do not favour the development of this pest.Pojava Diabrotica virgifera virgifera LeConte na teritoriji Srbije od 1992. godine, rezultirala je masovnim razmnožavanjem i brzim teritorijalnim širenjem. Brojnost populacije je povećavana iz godine u godinu, naročito u područjima gde je kukuruz gajen u monokulturi i dostizala je kritične vrednosti pri kojima nastaju ekonomske štete. Plodored i variranje klimatskih faktora značajno su uticali na pad brojnosti i ostale parametre dinamike populacije. Cilj istraživanja je bio da se formuliše strategija kojom bi se ostvarila ekološki racionalna kontrola kukuruzne zlatice, zasnovana na prognozi pojave i praćenju brojnosti imaga oba pola, u korelaciji sa klimatskim uslovima i sistemom gajenja kukuruza. Dinamika leta kukuruzne zlatice praćena je vizuelnom metodom, primenom feromonskih Csalomon, žutih (Pherocon AM®) i zelenih lepljivih klopki tipa Multigard, u periodu od početka jula do kraja septembra. Klopke su postavljane početkom jula, na biljke kukuruza iznad klipa, menjane su svake dve nedelje, a pregled klopki vršen je svaki treći dan. Dobijeni rezultati su ukazali na dominantan uticaj klimatskih prilika na ispitivane parametre. Razlike u brojnosti populacije uočene su na različitim tipovima klopki, godinama posmatranja i lokalitetima. Vizuelnim pregledom biljaka uočena su variranja u brojnosti imaga između lokaliteta i godina. Od ukupno 1.007 registrovanih imaga, 58,68% konstatovano je na području Crepaje i 41,33% u oglednom polju Instituta za kukuruz Zemun Polje. Od ukupno registrovanih 867 imaga u Zemun Polju u periodu od 2005-2007godine, na feromonskim klopkama bilo je 406 ili 46,8%, na žutim lepljivim 443 ili 51,09% i na zelenim lepljivim, Multigard klopkama, svega 18 ili 2,07%. Visok nivo populacije imaga za period od tri godine zabeležen je u Crepaji. Na žutoj lepljivoj klopci registrovano je 8.550 imaga, na zelenoj 12.101, a maksimum brojnosti po godini od 24.028 jedinki detektovan je na feromonskoj klopki. U narednom periodu, tokom 2008-2009 godine, ekstremno visoke temperature tokom vegetacije i niska relativna vlažnost vazduha, zajedno sa nedostatkom kvalitetne hrane, rezultirali su sporadičnim ulovima tokom avgusta do potpunog izostanka leta

Procena agronomskih i senzornih karakteristika hibrida kukuruza šećerca

Sweet corn is considered as tasty and quality food. Its kernels contain sugars that are in good balance with amino acids, minerals and vitamin B. It is used as fresh product right after the harvest, but also for further industrial processing, freezing and canning. In breeding of sweet corn, equal attention is paid to the production of high and stable yielding hybrids, and to the enhancement of technological and sensory properties of the ear and kernel. The aim of this re-search was to establish agronomic and sensory properties of 12 sweet corn hybrids, 3 commercial and 9 experimental. The trial was set up according to the RCBD on two locations and in three replicates. The evaluation of agronomic parameters encompassed: fresh ear yield without husk, ear length, number of kernel rows and shelling percentage. Also, sensory characteristics were analyzed: appearance, color, smell, sweetness, juiciness, crispiness, pericarp hardness. Sensory characteristics were evaluated by voluntary panelists and scaled with 1 – 9 point hedonic scale. Fresh ear yield significantly varied over locations and hybrids. The highest fresh ear yield had experimental hybrid ZP 481/1su – 13.33 t ha-1, while the lowest was 7.14 t ha-1 (ZP504su). The difference between sensory characteristics among hybrids was also noticed, although all hybrids had satisfactory sensory characteristics with the average sensory marks above 7.30/9.00. The best sweet corn hybrid according to sensory characteristics was ZP 483/1su (8.29), while the highest yielding one ZP 481/1su had an average sensory mark 7.70.Kukuruz šećerac se smatra ukusnim i kvalitetnim povrćem. Njegovo zrno sadrži šećere, ami-no-kiseline, minerale i vitamin B koji su u veoma dobrom odnosu. Koristi se u svežem stanju odmah nakon berbe, ali takođe i za industrijsku preradu i zamrzavanje zrna. U procesu ople-menjivanja kukuruza šećerca, podjednaka pažnja posvećuje se stvaranju hibrida visokog i sta-bilnog prinosa, kao i poboljšanju tehnoloških i senzornih karakteristika klipa i zrna. Cilj ovog istraživanja bio je da se utvrde agronomske i senzorne karakteristike 12 hibrida kukuruza šećerca, od kojih su tri hibrida bila komercijalna, a 9 eksperimentalnih. Ogled je bio postavljen po prin-cipu RCBD, na dve lokacije i u tri ponavljanja. Analiza agronomskih karakteristika obuhvatila je: prinos svežeg klipa bez komušine, dužinu klipa, broj redova zrna i randman zrna. Od senzornih karakteristika analizirane su sledeće: izgled klipa, boja, miris, slatkoća, sočnost, hrskavost i tvr-doća perikarpa. Senzorne karakteristike procenjivalo je 15 dobrovoljaca, koristeći skalu 1 – 9. Prinos svežeg klipa značajno je varirao u odnosu na lokacije i hibride. Najviši prinos postigao je eksperimentalni hibrid ZP 481/1su – 13,33 t ha-1, dok je najniži prinos bio kod hibrida ZP504su (7,14 t ha-1). Razlike u pogledu senzornih karakteristika između posmatranih hibrida takođe su primećene, ali svi hibridi su uglavnom imali zadovoljavajuće senzorne ocene sa srednjom vred-nošću preko 7,30/9,00. Najbolji hibrid kukuruza šećerca prema senzornim ocenama bio je ZP 483/1su (8.29/9,00), dok je najprinosniji hibrid ZP 481/1su imao nisku senzornu ocenu od 7,70

Proučavanje stabilnosti prinosa kukuruza neparametrijskim metodama

High and stabile yield in different production environments is priority in maize breeding. New statistical methods are constantly being sought to accompany analysis of variance, in order to achieve more reliable hybrid assessment. In this study nonparametric stability analysis is applied in order to assess GxE interaction for yield of 36 commercial maize hybrids. The experiment was set up at five locations in Serbia for three years according to the Randomised complete block design in three replications. Yield stability of investigated genotypes was analysed by stability parameters Si (1), Si (2), Si (3), Si (6) TOP and RS. Analysis of variance identified highly significant F values for all experimental factors. Bredenkamp method confirmed the existence of non-crossover GxE interaction, for maize yield. Hybrid ZPH15 achieved the most stable yield based on parameters Si (1) and Si (2). According to parameter Si (3) it was ZPH5, while based on parameter Si (6) it was ZPH34. The highest overall yield achieved ZPH36 (11.18 t ha-1 ), which was quite unstable (rank 24 in parameters Si (1) and Si (2)), and very unstable (rank 34 in parameters Si (3) and Si (6)). The most stable hybrids had average yields. In total, the hybrid ZPH23 had the best average rank (15.93). Based on TOP parameter, ZPH36 had the best rank (yield), followed by ZPH11, ZPH20, ZPH21 and ZPH9. However, RS parameter revealed that ZPH21 was the most stable hybrid, so taking into account both TOP and RS parameters this is the most productive and the most stable hybrid. Based on this research, TOP and RS are the best parameters for selecting new maize hybrids for production in particular environment. In case of identical TOP value, the genotype with the lowest RS value should be selected. The parameters Si (1), Si (2), Si (3) and Si (6) can be used as alternative methods for the selection of genotypes with moderate yield and high stability.U ovom radu primenjena je neparametarska analiza stabilnosti kako bi se procenila GxE interakcija za prinos 36 hibrida kukuruza. Eksperiment je postavljen na pet lokacija u Srbiji u trajanju od tri godine po potpuno slučajnom blok dizajnu (RCBD) u tri ponavljanja. Stabilnost prinosa ispitivanih genotipova analizirana je parametrima stabilnosti Si (1), Si (2), Si (3), Si (6), TOP i RS. Hibrid ZPH15 je postigao najstabilniji prinos na osnovu parametara Si (1) i Si (2), prema parametru Si (3) ZPH5, dok je na osnovu parametra Si (6) to bio ZPH34. Najrodniji hibrid ukupno u ogledu bio je ZPH36 sa prosečnim prinosom od 11,180 t/ha, koji je na osnovu ranga parametara Si (1) i Si (2) bio dosta nestabilan (rang 24), a na osnovu ranga parametara Si (3) i Si(6) veoma nestabilan (rang 34). Najstabilniji hibridi imali su prinos oko proseka. Ukupno, najbolji prosečan rang imao je hibrid ZPH 23 (15,93). Na osnovu TOP parametra najbolji rang (prinos) imao je ZPH36, a zatim ZPH11, ZPH20, ZPH21 i ZPH9. Međutim, RS parametar je pokazao da je ZPH21 najstabilniji hibrid, tako da je uzimajući u obzir i TOP i RS parametre ovo najproduktivniji i najstabilniji hibrid. Na osnovu ovog istraživanja, od svih posmatranih neparametarskih parametara, parametri TOP i RS pokazali su se kao najbolji za odabir novih hibrida kukuruza za gajenje u određenom regionu. U slučaju identične TOP vrednosti, treba izabrati genotip sa najnižom RS vrednošću, dok se parametri Si (1), Si (2), Si (3) i Si (6) mogu koristiti kao alternativne metode za selekciju genotipova sa umerenim prinosom i visokom stabilnošću

Effect of abiotic and biotic stress on alteration of phytochemicals in maize leaf and grain - aftereffect on food quality and safety

Upotreba kukuruza u ishrani ljudi i životinja ima široku primenu jer predstavlja izvor različitih tohemikalija koje povoljno utiču na metaboličke procese. Tokom vegetacije biljka kukuruza izložena je različitim uticajima abiotičkog i biotičkog stresa. Napad jedne od najznačajnijih štetočina kukuruza, larve Ostrinia nubilalis zavisi od uslova sredine i može dovesti do smenjenja prinosa i do 30%. Oštećenja nadzemnih delova biljke povećavaju rizik od pojave truleži klipa, jer predstavljaju mesta sekundarne infekcije izazvane različitim patogenim gljivama. Jedna od neophodnih agrotehničkih mera je primena pesticida u poljoprivredi u cilju suzbijanju kako štetočina tako i korova, obezbeđujući stabilan prinosa. S druge strane, primena pesticida, nepovoljni uslovi spoljašnje sredine i biotički stres mogu dovesti do oksidativnog stresa, oštećenja ćelija i pojave slobodnih radikala i reaktivnih vrsta kiseonika (engl. reactive oxygen species - ROS). Ćelije i tkiva biljaka imaju razvijene antioksidativne sisteme odbrane koji ihibiraju ili vezuju slobodne radikale. Najznačajniji neenzimski antioksidansi su avonoidi, fenolne kiseline, karotenoidi, tokoferoli, tinska kiselina, vitamin C, i glutation. Osim promena u prinosu i antioksidativnom statusu, kod biljke može doći i do promena u količini i drugih tohemikalija kao što su proteini, šećeri, amnokiseline i masne kiseline. Do sada su nedovljno ispitani uticaji pesticida i abiotički stres koji mogu da izazovu promene na različitim tkivima kukuruza, pri čemu je više pažnje posvećano promeni tohemikalija izazvanoj uticajem spoljašnje sredine kao što je vodni decit. U cilju pronalaženja karakterističnog odgovora genotipa, u odnosu na promene tohemijskog sadržaja, kao i eventualno izdvajanje genotipa tolerantnog na potencijalni stres primenjuju su metode spekrofotometrije i savremene metode tečne i gasne hromatograje za odredjivanje tohemikalija u biljci.The use of maize in human nutrition and livestock feed is widely used because it is a source of various phytochemicals that have a positive efect on metabolic processes. During the growing season, the maize plant is exposed to various influences of abiotic and biotic stress. Ostrinia nubilalis larvae, one of the predominant maize pests, can reduce plant growth and cause stalk and ear damage, leading to a yield decrease of up to 30%. Damage to the above-ground parts of the plant increases the risk of cob rot, presenting sites of secondary infection caused by pathogenic fungi. One of the necessary agrotechnical strategies is the application of pesticides in order to control both pest and weed impact, providing stability of yield. On the other hand, the application of pesticides, negative environmental impacts, and biotic stress can lead to oxidative stress, cell damage and the appearance of free radicals and reactive oxygen species (ROS). Cells and plant tissues have developed antioxidant defense systems that inhibit or bind free radicals. The most important non-enzymatic antioxidants are flavonoids, phenolic acids, carotenoids, tocopherols, phytic acid, vitamin C, and glutathione. In addition to changes in yield and antioxidant status, alteration of other phytochemicals such as proteins, sugars, amino acids and fatty acids can also occur in the plant. The effects of pesticides and abiotic stress that they can cause on different tissues of maize have been insufficiently investigated. More attention has been given to the changes in phytochemicals content caused by the influence of the environment such as water deficit. In order to find the response of the genotype, in relation to changes in the phytochemical content, as well as the eventual selection of a genotype tolerant to potential stress, spectrophotometry methods and modern methods of liquid and gas chromatography were applied to determine phytochemicals in the plant

Influence of insecticides on total canal lenght in the corn stem formed by feeding Ostrinia nubilalis larvae

The aim of this study was to determine the effect of insecticides on the total length of canals in corn stems formed by the feeding of larvae of Ostrinia nubilalis. The research was carried out in the experimental field of the Zemun Polje Maize Institute in 2018. Two maize hybrids of different FAO ripening groups (ZP 427 and ZP 666) were tested. Two insecticides were compared on the total canal length in corn stalks in order to determine if there is a statistically significant difference in the effect of the applied insecticides. The preparations Coragen SC with the active substance chlorantraniliprole and Phobos EC with the active substance bifenthrin were used. At the end of the corn harvest, the plants were dissected, where, in addition to other measurements, the length of the canals formed by the feeding of the larvae of the corn borer was measured. The results showed that there is a significant difference between treated and untreated plants. The best results were achieved with the insecticide with the active substance chlorantraniliprole in hybrid ZP 427, where the total length of all channels formed by feeding O. nubilalis larvae was 166.67 cm, while the worst results were found in the control variant of hybrid ZP 666 with 278.33 cm

Uticaj različitih pesticida i napada kukuruznog plamenca na sadržaj fitinskog fosfora u zrnu kukuruza

This work aimed to evaluate changes in phytic phosphorus content as the response of three maize hybrids (ZP 457, ZP 5601, and ZP 606) to different pesticide treatments for European Corn Borer (ECB) attacks and, as well as the correlation between damage caused by ECB attack and Pphy content. In the experimental field, maize ears were sampled and dried at a moisture content of 14% for the determination of changes in phytic phosphorus content in the grain. The content of phytic phosphorus was determined using UV / VIS spectrophotometry. Observed results showed the highest content of phytic phosphorus for untreated control for all tested hybrids, compared to pesticide treatments. The content of Pphy in the tested maize kernel samples ranged from 2.12 to 3.40 mg g -1. A significant positive correlation between attacks of larvae and Pphy content could indicate activation of its antioxidative function as a response to damage caused by ECB attack.Cilj ovog rada je procena promene u sadržaju fitinskog fosfora kao odgovora tri hibrida kukuruza (ZP 457, ZP 5601 i ZP 606) na različite tretmane pesticidima protiv napada kukuruznog plamenca, kao i određivanje korelacije između oštećenja biljke izazvane napadom larvi i sadržaja fitinskog fosfora. U oglednom polju uzorkovani su klipovi kukuruza radi određivanja promene sadržaja fitinskog fosfora u zrnu UV/VIS spektrofotometrijom. Dobijeni rezultati su pokazali najveći sadržaj fitinskog fosfora za netretiranu kontrolu kod svih ispitivanih hibrida u poređenju sa tretmanima pesticidima. Sadržaj fitinskog fosfora u ispitivanim uzorcima zrna kukuruza kretao se od 2,12 do 3,40 mg g-1. Uočena značajna pozitivna korelacija između napada larvi i sadržaja fitinskog P može ukazivati na aktivaciju njegove antioksidativne funkcije kao odgovor na oštećenja izazvana napadom kukuruznog plamenca

Uticaj insekticida na ukupan procenat napada Ostrinia nubilalis Hbn kod hibrida kukuruza

The objective of the paper was to determine the effect of insecticides on the development of the European corn borer (Ostinia nubilalisHbn) and the effect of damage in six maize hybrids of different maturity groups. The research involved the following hybrids: ZP 427, ZP 434, ZP 555, ZP 600, ZP 606 and ZP 666. In the field trial, insecticides were applied in two terms, during the flight of O. nubilalisfirst generation and during theflight ofsecondO. nubilalisgeneration. We used Fobos EC insecticide and a combination of Match 050 EC + Nurelle D insecticides, whose active substances are different. The active substance in Fobos EC insecticide is bifenthrin 100 g l-1, in Match 050 EC lufenuron 50 g l-1 and, in Nurelle D insecticide, the active ingredient is a combination of chlorpyrifos 500 g l-1and cypermethrin 50 g l-1. The damageinflicted on plants was assessed in July and September. Fobos insecticide had the best plant protection effect, after its use, the arithmetic mean of the total attack percentage of all hybrids was approximately 81.62% while in the control group, it was approximately 91.72%.Cilj rada je bio da se utvrdi efekat insekticida na razvoj kukuruznog moljca (Ostinia nubilalisHbn) i efekat oštećenja u šest hibrida kukuruza razliĉitih grupa zrenja. Istraţivanje je obuhvatilo sledeće hibride ZP 427, ZP 434, ZP 555, ZP 600, ZP 606 i ZP 666. U ogledu, insekticidi su primenjeni u dva termina i to: u vreme leta prve generacije O. nubilalisi posle toga u vreme letenja druge generacije O. nubilalis. U istraţivanjima su korišćeni insekticidi: Fobos EC insekticid i kombinacija insekticida Match 050 EC + Nurelle D ĉije su aktivne supstance razliĉite. Aktivna supstanca kod insekticida FobosEC je bifentrin 100 g l-1, kod Match 050 EC je lufenuron 50 g l-1, a kod insekticida Nurelle D aktivna supstanca je kombinacija hlorpirifos 500 g l-1i cipermetrin 50 g l-1. Ocena oštećenja na biljkama je vršena u julu i septembru u godini eksperimenta. Insekticid Fobos je imao nabolji efekat zaštite biljaka. Ustanovljen je najbolji efekat Fobosa u zaštiti biljaka, posle ĉije primene je nadjeno oštećenje kod 81.62% proseĉno za sve hibride, što je znaĉajno razliĉito od napada kukuruznog plamenca na kontrolnoj varijanti, bez upotrebe insekticida, na kojoj je nadjeno 91,72% napadnutih biljaka proseĉno za sve hibride. U analizi tretmana insekticidima, najniţi ukupni napad je nadjen kod ZP 434 hibrida i to 77,12% napadnutih biljaka posle tretmana Fobos (I-1); dok je najveći ukupni napad (88.55%) nadjen kod ZP 555 hibrid posle tretmana Match + Nurelle (II-1). U proseku primena insekticida u vreme prve generacije napada je bila efikasnija nego primena insekticida u vreme razvijene druge generacije kukuruznog plamenca (Ostrinia nubilalis). Intenzitet napada prve generacije kukuruznog plamenca, je bio najniţi kod ZP 666 hibrida (13,07%) u varijanti primenjenog insekticida Fobos (I-1), dok je najviši u ZP 427 hibrida -35.54%. Napad druge generacije je bio najmanjeg intenziteta kod ZP 434 hibrida (43,24%), a najviša u ZP 666 hibrida (68,62%) posle tretmana sa insekticidom Fobos (I-1). Proseĉno za sve hibride najveći intenzitet napada u vreme prve, kao i u vreme druge generacije kukuruznog plamenca je ustanovljen u kontrolnoj varijanti (bez tretmana insekticidom) koji je bio veći u odnosu intenzitet napada na tretiranim varijantama sa insekticidom. Na kontrolnoj varijanti, intenzitet napada ocenjen u vreme prve generacije O. nubilalisje vrarirao u rasponu od najvećeg kod ZP 606 hibrida (69.29%), do najmanjeg kod ZP 434 hibrida (64.36% ), dok je u vreme druge generacije intenzitet napada varirao u rasponu od najvećeg kod ZP 666 hibrida (26,93%) do najmanjeg kod kod ZP 555 hibrida (23.9%)