Vilina kosica i mogućnosti suzbijanja

Dodder (Cuscuta spp.) is the most wide-spread parasitic plant in our regions. Over the past several years it has increasingly expanded. Apart from growing in alfalfa and red clover as its main host crops, it is now beginning to pose a growing threat to the other crops, as well. About ten dodder species had been determined in Serbia in the past, but they have been out of focus of detailed research in the past three decades. Two dodder species have been identified as important: the small-seeded (Cuscuta trifoli Bab.), and large-seeded (C. campestris Yuncker). They differ in many respects, including the loci of binding to their host-plants. Methods of controlling dodder include preventive measures, and mechanical and chemical control.Vilina kosica (Cuscuta spp.) je najrasprostranjenija parazitska biljka na našim prostorima. Poslednjih godina primećena je njena ekspanzija, a pored lucerke i deteline, kao njenih osnovnih domaćina, počinje da ugrožava i druge gajene biljke. Zakonska regulativa, kojom se sprečava širenje viline kosice semenom, nedovoljno se poštuje. U zaštiti useva se ne poklanja dovoljno pažnje borbi protiv viline kosice, ruderalna staništa oko naših njiva su izrazito zakorovljena i pravi su rasadnik ovog parazita, te ovakvo stanje izaziva sve veće probleme. Najefikasniji način borbe sa vilinom kosicom je sprečavanje njenog unošenja u useve, ali kada se ona javi, primena herbicida može dati zadovoljavajuće rezultate

Novije mogućnosti suzbijanja korova u pšenici

Weed control is achieved only by utilizing herbicides and adequate agro-technical measures for wheat, with the use of herbicides against dominant types of weed in a rotating system of plant and vegetable cultures. The most certain solution to the problem of weeds in wheat is to stop sprouting and spreading of resistant weeds. The solution to the problem is facilitated by using a system of rotating plant types and the introduction of specific herbicides based on fluoroxipire, amidosulfurine, florasuluam and cinidon ethyl, depending on the appearance of problem weeds. Within the system of wheat management, regional and global models for controlling weeds for period over 5 years are formed, which implies fundamental changes to the introduction of novel technologies, transgenic cultivars and new herbicides.U radu je prikazan model suzbijanja korova u pšenici i stepen efikasnosti i selektivnosti herbicida u sistem menadžmenta i integralne zašite ratarskih useva na regionalnom i globalnom planu. Problem otpornih rezistentnih korova se pojednostavljuje i jednostavno rešava rotacijom useva i herbicida sa različitim načinima delovanja, te uvođenjem odgovarajućih mera, novih specifičnih herbicida za suzbijanje ruralnih i problematičnih korova u pšenici. Na taj način se sprečava nicanje i širenje rezistentnih korova u sistemu smene useva pšenice. šećerne repe, soje, kukuruza i soje

Različiti aspekti inhibicije rastenja i fotosinteze kukuruza (Zea mays L.) uzrokovanog herbicidom sulfosatom, 1 - manipulacija statusom korena

Effects of the herbicide sulphosate on growth, accumulation and partitioning of dry weight and photosynthesis in maize plants subjected to source-sink manipulation at the root were studied. The findings indicate that growth and dry weight accumulation correlate significantly only with the dry mass ratio and/or volume of the root (RMR, Vr, respectively), while a significant negative correlation was found with stem mass ratio (SMR) and generally with leaf mass ratio (LMR), which reflects an irregular distribution of carbohydrate metabolism in maize plants. As the root is where cytokinins, the plant hormons essential for maintaining photosynthetic structures, are synthesized, we assumed that the root status under stress caused by the herbicide sulphosate could be one of the factors of stability/sensitivity of photosynthesis/photosynthetic structures in plants exposed to this herbicide.U radu je razmatran uticaj herbicida sulfosata na rastenje, akumulaciju i preraspodelu suve mase, kao i fotosintezu biljaka kukuruza na kojima je vršena manipulacija "proizvod-potrošač" odnosa na nivou korena. Nađeno je da akumulacija suve mase značajno Koreliše samo sa zapreminom i/ili udeonom suvom masom korena (Vr, RMR), a negativno značajno sa udeonom suvom masom stabla (SMR) i (uglavnom) listova (LMR), što je u skladu sa neravnomernom preraspodelom ugljenohidratnog metabolizma kod biljaka kukuruza. Poznato je da je koren mesto sinteze citokinina, biljnih hormona neophodnih u održavanju fotosintetskih struktura. Pošto rezultati ukazuju na značaj statusa korena u uslovima stresa izazvanim herbicidom sulfosatom, smatramo da isti može biti jedan od faktora stabilnosti /osetljivosti fotosinteze/ fotosintetskih struktura kod biljaka izloženih dejstvu pomenutog herbicida

A new association of ruderal weeds at Pančevački Rit in Serbia

A several-year study of distribution, phytocoenological differentiation, floristic composition and structure of ruderal flora and vegetation and relevant anthropogenic influence was conducted at Pančevački Rit in Serbia. Ten clearly distinctive ruderal communities were identified in the study, including the newly formed community Matricario-Helianthetum annuae. This community is a unique combination of transitional ruderal and agrestal vegetation developing spontaneously in close vicinity of intensively cultivated agricultural fields, in which sunflower (Helianthus annuus L.), an annual crop, appears and persists subspontaneously and often massively, rendering a physiognomical character to ruderal habitats in which ephemeral ruderal weed vegetation often develops, consisting predominantly of annual plants of Sisymbrion officinalis R.Tx., Lohm. et Prsg.1950

Osetljivost kukuruza na interakciju sulfonilurea herbicida i zemljišnih insekticida

A field experiment was carried out to determine the presence of interaction between the insecticides terbufos, phorate, malathion + fenitrothion, carbofuran, and carbosulfan and the sulfonylurea herbicides primisulfuron-methyl, rimsulfuron, nicosulfuron, thifensulfuron-methyl and prosulfuron. The highest levels of phytotoxicity resulting from the terbufos by sulfonylurea interaction were observed in the treatments with the most precipitation after the application of the insecticide and just before that of the herbicide. No interaction or plant damage were recorded with the application of the soil insecticides carbosulfan, carbofuran, and malathion + fenitrothion at planting and the application of the herbicides primisulfuron-methyl, rimsulfuron, nicosulfuron, thifensulfuron-methyl and prosulfuron after the emergence of maize. However, the use of the soil insecticides terbufos and phorate and the herbicides primisulfuron-methyl, rimsulfuron, nicosulfuron, thifensulfuron-methyl resulted in significant phytotoxicity being found on maize plants. Prosulfuron was the only sulfonylurea that did not cause significant phytotoxicity when used in conjunction with terbufos or phorate.U poljskim uslovima ispitivana je interakcija između sulfonilurea herbicida primisulfuron-metila, rimsulfurona, nikosulfurona, tifensulfuron-metila i prosulfurona sa zemljišnim insekticidima terbufos, forat, malation + fenitrotion, karbofuran i karbosulfan. Najveći intenzitet fitotoksičnosti usled interakcije bio je u ogledima sa više padavina posle primene insekticida, a neposredno pre primene herbicida. Interakcija nije potvrđena u slučajevima primene zemljišnih insekticida karbosulfan, karbofuran, kombinacije malation + fenitrotion sa setvom i herbicida primisulfuron-metil, rimsulfuron, nikosulfuron, tifensulfuron-metil i prosulfuron posle nicanja kukuruza. Međutim, značajna fitotoksičnost na biljkama kukuruza bila je u slučajevima primene insekticida terbufos i forat sa herbicidima primisulfuron-metil, rimsulfuron, nikosulfuron i tifensulfuron-metil. Prosulfuron je bio jedini predstavnik ispitivanih sulfonilurea koji nije izazavao značajnu fitotoksičnost prema kukuruzu u slučajevima zajedničke primene sa terbufosom i foratom

Uticaj zemljišnog insekticida terbufos na selektivnost sulfonilurea herbicida prema kukuruzu

A three-year field trial was set up to study the effect of the soil insecticide terbufos on the selectivity of primisulfuron-methyl, rimsulfuron, and nicosulfuron towards three maize hybrids. The use of primisulfuron-methyl, rimsulfuron, and nicosulfuron after the application of the soil insecticide terbufos resulted in significant plant damage and a decrease of the above-ground plant weight and height, plant height and grain yield in three maize hybrids. The most susceptible hybrid was NS 420, while NS 375 and NS 640 exhibited approximately the same levels of tolerance towards the interaction between terbufos and the sulfonylureas. The highest levels of phytotoxicity resulting from the terbufos by sulfonylurea interaction were observed in the treatments with the most precipitation after the application of the insecticide and just before that of the herbicide.U trogodišnjim poljskim ogledima, ispitivan je uticaj zemljišnog insekticida terbufos na selektivnost primisulfuron-metila, rimsulfurona i nikosulfurona prema tri hibrida kukuruza. Primena primisulfuron-metila, rimsulfurona i nikosulfurona posle primene zemljišnog insekticida terbufos, prouzrokovala je jaču fitotoksičnost, smanjenje sveže mase nadzemnog dela biljaka, visine biljaka i prinos zrna tri hibrida kukuruza. Najosetljiviji hibrid bio je NS 420, dok su NS 375 i NS 640 ispoljili približan nivo tolerantnosti na interakciju ispitivanih sulfonilurea i terbufosa. Najveći intenzitet fitotoksičnosti usled interakcije bio je u ogledima sa više padavina posle primene insekticida, a neposredno pre primene herbicida

Stellaria media, klijanje, zelena svetlost, tamnocrvena svetlost, fitohrom A

The effects of green and far red light on germination of common chickweed (Stellaria media (L.) Vill.) seeds were compared to determine a possible mechanism of activity of green light in the germination process of chickweed. A brief irradiation with far red light on the first day of imbibition was found to inhibit germination at a certain percentage but it was followed by a stimulating effect, which became evident on the second day of imbibition. Green light was not found to inhibit germination and its stimulating effect began simulataneously with the stimulating effect of far red light. The results indicate a possible role of phytochrome A in stimulation by green light.Upoređivan je uticaj zelene i tamnocrvene svetlosti na klijanje semena mišjakinje (Stellaria media (L.) Vill.) da bi se utvrdio mogući mehanizam delovanja zelene svetlosti na ovaj proces kod mišjakinje. Pokazano je da kratkotrajno osvetljavanje tamnocrvenom svetlošću tokom prvog dana imbibicije inhibira klijanje u određenom procentu, a zatim počinje da deluje stimulativno, što je potpuno očigledno tokom drugog dana imbibicije. Zelena svetlost ne inhibira klijanje, a njen stimuliativni efekat počinje u isto vreme kada i stimulatvni efekat tamnocrvene svetlosti. Rezultati ukazuju na moguću ulogu fitohroma A u stimulativnom delovanju zelene svetlosti

Uticaj zemljišnog insekticida terbufos na selektivnost sulfonilurea herbicida prema kukuruzu

A three-year field trial was set up to study the effect of the soil insecticide terbufos on the selectivity of primisulfuron-methyl, rimsulfuron, and nicosulfuron towards three maize hybrids. The use of primisulfuron-methyl, rimsulfuron, and nicosulfuron after the application of the soil insecticide terbufos resulted in significant plant damage and a decrease of the above-ground plant weight and height, plant height and grain yield in three maize hybrids. The most susceptible hybrid was NS 420, while NS 375 and NS 640 exhibited approximately the same levels of tolerance towards the interaction between terbufos and the sulfonylureas. The highest levels of phytotoxicity resulting from the terbufos by sulfonylurea interaction were observed in the treatments with the most precipitation after the application of the insecticide and just before that of the herbicide.U trogodišnjim poljskim ogledima, ispitivan je uticaj zemljišnog insekticida terbufos na selektivnost primisulfuron-metila, rimsulfurona i nikosulfurona prema tri hibrida kukuruza. Primena primisulfuron-metila, rimsulfurona i nikosulfurona posle primene zemljišnog insekticida terbufos, prouzrokovala je jaču fitotoksičnost, smanjenje sveže mase nadzemnog dela biljaka, visine biljaka i prinos zrna tri hibrida kukuruza. Najosetljiviji hibrid bio je NS 420, dok su NS 375 i NS 640 ispoljili približan nivo tolerantnosti na interakciju ispitivanih sulfonilurea i terbufosa. Najveći intenzitet fitotoksičnosti usled interakcije bio je u ogledima sa više padavina posle primene insekticida, a neposredno pre primene herbicida

Uticaj godišnjih promena temperature i svetlosti (PAR) na indukciju fluorescencije Chla in situ kod Stellaria media (L.) i Plantago maior (L.)

Chla fluorescence, as a mode of estimation of photosynthesis, is especially sensitive to changes in temperature and light intensity (PAR). This enables us to study the influence of those ecophysiological parameters on photosynthesis in native plants. In this article, we examined the effect of annual changes in temperature and PAR on the parameters of Chla fluorescence in Stellaria media (L.), a plant species more frequent in colder periods of the year, and Plantago maior (L.), which is more frequent in warmer periods. Lower PAR and temperature slowed down the electron transport in PS2, but lower temperatures reduced the quantum efficacy of PS2 and improved processes in the antennae system and the size of plastoquinone pool of PS2 in Stellaria media (L.). Lower temperatures reduced quantum efficacy and slowed down the electron transport in PS2 in Plantago maior (L.). The facts that PAR (as well as temperature) affects photosynthesis, and that lower temperatures activate processes in the antennae system and those on the acceptor side of PS2 as a 'counterbalance' to the inhibition of quantum efficacy and electron transport in PS2, caused by low temperatures, point at possible explanations of low-temperature resistance of photosynthesis in Stellaria media (L.). On the other hand, low temperatures caused inhibition of quantum efficacy and electron transport in the PS2 of Plantago maior (L.), which caused low-temperature photoinhibition and stepped quenching of all physiological processes in the species. This might be the reason for the different levels of acclimation to low temperatures and different life strategies of the two species living in close vicinity.Fluorescencija Chla, kao pokazatelj fotosinteze, posebno je osetljiva na promene temperature i intenziteta svetlosti (PAR). To omogućava praćenje uticaja ovih ekofizioloških parametara na fotosintezu nativnih biljaka. U ovom radu dat je pregled uticaja godišnjih promena temperature i PAR na parametre fluorescencije Chla kod Stellaria media (L.), biljne vrste zastupljenije u hladnijem delu godine i Plantago maior (L.), biljne vrste zastupljenije u toplijem delu godine. Manje vrednosti PAR i temperature usporavaju transport elektrona u PS2, sniženje temperature umanjuje kvantnu efikasnost u PS2 i pozitivno deluje na antenske procese i veličinu pula plastohinona u PS2 kod Stellaria media (L.). Sniženje temperature umanjuje kvantni prinos i usporava transport elektrona u PS2 kod Plantago maior (L.). Činjenica da i PAR (pored temperature) deluje na fotosintezu, kao i da sniženje temperature aktivira antenske i procese na akceptorskoj strani PS2, kao "protivtežu" inhibiciji kvantne efikasnosti i transporta elektrona u PS2, uzrokovanoj niskim temperaturama, ukazuje na moguće uzroke niskotemperaturne otpornosti fotosinteze kod Stellaria media (L.). Nasuprot tome, kod Plantago maior (L.) niska temperatura uzrokuje inhibiciju kvantne efikasnosti i transporta elektrona u PS2, što dovodi do niskotemperaturne fotoinhibicije i postepenog gašenja svih fizioloških procesa kod te vrste. To bi moglo biti objašnjenje različite prilagođenosti na niske temperature i različitih životnih strategija ovih vrsta, koje žive u bliskom susedstvu