Chromosome numbers of invasive and potentially invasive species in the flora of the Republic of Altai. Post V

Chromosome numbers (2n) of 15 invasive and potentially invasive plant species from the families Asteraceae, Brassicaceae, Caryophyllaceae, Malvaceae, Onagraceae, Papaveraceae, Plantaginaceae, Poaceae, Polygonaceae, Portulacaceae, and Rosaceae are reported on the samples collected in the Republic of Altai. To determine the chromosome number (ploidy level), the method of direct counting was used. Among studied species, chromosome complements for Persicaria orientalis (2n = 22), Potentilla norvegica (2n = 42), Veronica persica (2n = 28) were first examined from Russia; for Papaver rhoeas (2n = 14) and Rumex obtusifolius (2n = 20) – from Asian part of Russia; for Bromus squarrosus (2n = 14), Cosmos bipinnatus (2n = 24), and Eriochloa villosa (2n = 54) – from Siberia. Abutilon theophrasti (2n = 42) and Lepidium densiflorum (2n = 32) were first studied from Western Siberia; Epilobium ciliatum subsp. adenocaulon (2n = 36), Portulaca oleracea (2n = 36), Spergularia rubra (2n = 36), and Xanthium strumarium (2n = 36) – from the Republic of Altai. Common distribution and the history of floristic findings of these species in the Republic of Altai are given. Previously published data on chromosome numbers from Russia are cited.

First Report on the Occurrence of Benzoxazinoids in an Invasive Weed Plant, Woolly Cupgrass (Eriochloa villosa (Thunb./Kunth)

Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) is a common weed in East Asia and North America. This weed plant spreading quickly in Europa. There are several reasons for the successfulness, especially its germination properties. As other Panicoideae species contain benzoxazinoids it was supposed that woolly cupgrass also contains these chemicals. For this reason the benzoxazinoid content of plants at the stage of flowering was investigated. As it was supposed, woolly cupgrass contain benzoxazinoids, which is a novel occurrence of these chemicals in Poaceae family.

Az ázsiai gyapjúfű (Eriochloa villosa) elterjedésének vizsgálata Borsod-Abaúj-Zemplén megye északi részén

Az Eriochloa villosa (Thunb.) Kunth első magyarországi adata 2007-ből származik. Az azóta eltelt idő­szakban a faj intenzíven terjedt, az ország több pontján megjelent. A felmérések során Bor­sod-Abaúj-Zemplén megye északi részén vizsgáltuk a faj jelenlegi elterjedését. Arra kerestük a vá­laszt, hogy első megtelepedésének környékén mekkora területen terjedt el és ettől a területtől el­kü­lö­nül­ten, a vizsgált terület más részén is megjelent-e. A közleményben áttekintjük a hazai és az or­szág­ha­tár közeléből származó külföldi adatokat is. A felmérés során 58 lokalitásban találtuk meg a fajt, el­ső­sor­ban szántó­földeken, parlagokon, de zavart gyepekben is előfordult. Az 2007-ben megtalált lelőhely kör­nyezetében nagy területen elterjedt, de attól távolabb is megjelent, így a Sajó- és Bódva-völgyben, il­let­ve a Csere­hátban. Az Eriochloa villosa további terjedésére kell számítanunk, különösen az intenzív szán­tóföldi művelés alatt álló területeken, a zavart nyílt gyepeken, de megjelenése elképzelhető nyílt ter­mészetes élőhelyeken is.

Allelopathic effect of invasive plants (Eriochloa villosa, Asclepias syriaca, Fallopia x bohemica, Solidago gigantea) on seed germination

The aim of this study was to determine the allelopathic potential of invasive species woolly cupgrass (Eriochloa villosa), common milkweed (Asclepias syriaca), bohemian knotweed (Fallopia x bohemica), and giant goldenrod (Solidago gigantea Ait.) on germination crop (Lepidium sativum L.). Experiments were conducted under laboratory conditions to determine effect of water extracts in petri dish bioassay. Water extracts from fresh biomass (leaves and stem) of invasive weeds in concentrations of 4 and 8 g/100 ml were investigated. All invasive plants showed allelopathic effect on germination. In giant goldenrod stem water extract experiment, allelopathic effect was less pronounced. The cress germination was greatly suppressed with the woolly cupgrass, common milkweed and the giant goldenrod. The experiment showed that the seed germination depended on the concentrations and the plant material used (leaves and stem).

New occurence of woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) in Hajdúság area, East-Hungary

Because of the globalization and global warming the emergence of invasive weeds in Hungary are more common. The woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) is published as an important invasive weed in Hungary. Woolly cupgrass is native in East Asia and it spreads into several parts of the World and causes difficulties in plant protection. It has been spreading extensively during the last few years,as the weed shows a very serious invasion potential.

Allelopathic effects of water extracts of pieces of wooly cupgrass (Eriochloa villosa) on the seedlings of field crops

In Hungary, the woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) endanger row crops (i.e. corn, sunflower). Its fast spreading based on some reason viz. long-lasting emergence, reduced sensitivity to many kinds of herbicides, vigorous competitional ability and fast initial growth. Allelopathy, ability of many plant species to produce one or more biochemicals wgich is used tocompete with each others. In this experiment we examined, whether the woolly cupgrass possesses allelopathy, and if so, how influences on the development of cultured crops like maize, sunflower and lettuce.

Fusarium culmorum isolated from rhizosphere of wooly cupgrass (Eriochloa villosa) in Debrecen (East Hungary)

Wooly cupgrass (Eriochloa villosa) is an East-Asian originated weed species and it has been spreaded worldwide by now. The first occurrence of this species in Hungary was observed and published in 2008 nearby Gesztely village (Borsod-Abaúj-Zemplén county, North-East Hungary) than in the summer of 2011 a significant population was discovered next to Debrecen city (Hajdú-Bihar county, East Hungary). In 2013 this weed was also reported from Szentborbás village, Somogy county (South-West Hungary). These observations of spreading and its biological features (production of stolons and large number of seeds, moreover herbicide tolerance) indicate that wooly cupgrass (E. villosa) has a great potential of invasiveness, so it may become a hazardous weed not only in Hungary but in all over the world. The objective of this study was to identify the fungus which was isolated from wooly cupgrass (E. villosa) root residue samples which were collected after maize harvesting on arable land in late autumn, near Debrecen. The identification of the fungus based on morphological characters of colonies and the features of conidia developed on potato dextrose agar (PDA) plates. After the examination of axenic culture we revealed that the fungus from rhizosphere of wooly cupgrass was Fusarium culmorum. Pathogenicity and/or endophytic relationship between the fungus and wooly cupgrass is still uncertain so pathogenicity tests and reisolations from plants are in progress.

Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability

Nurse, R. E., Darbyshire, S. J. and Simard, M.-J. 2015. Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability. Can. J. Plant Sci. 95: 1193–1197. Herbicides are generally applied at early stages of crop and weed growth to protect crop yield. Few studies have evaluated the effect of late (post-anthesis) applications of glyphosate as a management option to limit the seed production of weed escapes, such as woolly cupgrass (Eriochloa villosa). We propagated woolly cupgrass under greenhouse conditions and then applied three glyphosate treatments post-anthesis including: (1) an untreated control; (2) 900 g a.e. ha−1; and (3) 1800 g a.e. ha−1. Terminal inflorescences were collected 21 d after glyphosate application, and seed production, seed weight and embryo viability were assessed. Post-anthesis glyphosate applications did not influence seed production, but reduced seed weight and viability by 50 and 96%, respectively. Therefore, glyphosate applied just before the woolly cupgrass inflorescence begins to emerge from the leaf sheath (as late as the R1 stage in soybeans) is an effective strategy to manage woolly cupgrass reproduction and stop viable seeds from entering the soil seed bank or other dispersal pathways.

Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth), a recently occured invasive weed in Trans-Tisza Region and a trial for control in maize

To the effective control of invasive weeds are essential to prevent establish, if has already happened obstacle to massive accumulation, and promoting the efficient and rapid eradication, if it is possible. The Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) belongs to weeds which “hard to control” especially in corn. One of the difficulties of effective control is the prolonged emergence causing avoidance of several individuals the contact with pre-emergent herbicides. Another problem arises due to the intensive use of post-emergence herbicide products with short duration of action. To optimalize of timing of treatment is essential for successful control of later emerging weeds. The recently established Woolly cupgrass in Hungary shows resistance or reduced susceptibility to substantial portion of herbicides used in corn. The data collected from small-plot trials demonstrates that application of sulfonylurea or selective monoctyledonous herbicides can be effective against the Woolly cupgrass.