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

Chromosome numbers (2n) in 10 invasive and potentially invasive plant species from the families Asteraceae, Brassicaceae, Caryophyllaceae, Fabaceae, Malvaceae, Oxalidaceae, Poaceae and Solanaceae are reported on the samples collected in the Republic of Altai. To determine the ploidy levels, we used methods of direct chromosome counting and flow cytometry in some cases. Among them, chromosome complements were first examined in Russia for Eruca vesicaria subsp. sativa (2n = 22). Psammophiliella muralis (2n = 34), Medicago sativa subsp. varia (2n ≈ 32; 2C = 4.8 pg) and Solanum nigrum (2n = 48) were first studied from Siberia. Malva verticillata (2n = 42), Oxalis dillenii (2n = 24), Lolium perenne (2n = 14) and Setaria faberi (2n = 36) were first studied from the Republic of Altai. Tetraploid cytotype and genome size of Picris hieracioides (2n = 4x = 20; 2C = 8.89 pg) were discovered for the first time. 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.

Weed Control in Dicamba-Resistant Soybean with Glyphosate/Dicamba Applied at Various Doses and Timings

Seven field trials were completed over a three-year period (2016 to 2018) in southwestern Ontario, Canada, to assess weed control in conventional-till dicamba-resistant (DR) soybean with glyphosate/dicamba (2 : 1 ratio) applied postemergence (POST) at 3 doses (900, 1350, and 1800 g·ae·ha−1) and 3 application timings (up to 5, 15, and 25 cm weeds). There was minimal soybean injury (≤2%) from treatments evaluated. Glyphosate/dicamba applied at application timing of up to 5, 15, and 25 cm weeds, controlled Amaranthus spp. (pigweed spp.) 87–96, 94–99, and 99%; Ambrosia artemisiifolia (common ragweed) 93–99, 97–99, and 99–100%; Chenopodium album (lambsquarters) 89–99, 95–100, and 99–100%; Echinochloa crus-galli (barnyardgrass) 81–84, 94–96, and 96–97%; Setaria faberi (giant foxtail) 37–90, 77–98, and 99–100%; and Setaria viridis (green foxtail) 94–96, 99, and 99–100%, respectively. Additionally, glyphosate/dicamba applied POST at 900, 1350, and 1800 g·ae·ha−1 controlled Amaranthus spp. 90–97, 95–98, and 97–99%; A. artemisiifolia 95–98, 97–99, and 99–100%; C. album 92–99, 95–100, and 98–100%; E. crus-galli 84–88, 93-94, and 95-96%; S. faberi 74–95, 75–97, and 79–98%; and S. viridis 98, 98–99, and 98–100%, respectively. Weed interference reduced DR soybean yield as much as 51% compared to the highest yielding treatments. Results indicate that glyphosate/dicamba applied POST at the label doses can provide an adequate control of troublesome weeds in DR soybean. Weed control was generally most consistent when glyphosate/dicamba was applied at the highest registered dose in Ontario (1800 g·ae·ha−1) and when weeds were up to 25 cm tall.

Electricity generation from living plants using microbial fuel cells

The need for a sustainable source of energy has catered engineers to discover and develop a biological battery known as Plant Microbial fuel cell. This biological battery operates with the help of electrochemically active bacteria in presence of CO2, sunlight and water. This technique is gaining importance in the field of bioelectricity as it produces clean in-situ energy from living plants without the need to harvest the plant species. Research on these cells have led to the development of various models. One such plant species Setaria faberi was tested for its compatibility in sediment plant microbial fuel cell. Power density of 4.6mW/m2 was obtained when it was tested with cocopeat as a hydroponic media. This paper highlights the suitability of S. faberi in producing sustainable bioelectricity with a hydroponic media.

Reduced Translocation Is Associated with Antagonism of Glyphosate by Glufosinate in Giant Foxtail (Setaria faberi) and Velvetleaf (Abutilon theophrasti)

Previous reports have underscored antagonism that may result from mixing glyphosate and glufosinate across a wide range of application rates and for various broadleaf and grass weed species, but no investigation has been conducted to characterize glyphosate absorption and translocation when combined with glufosinate. The objectives of this study were to evaluate herbicide efficacy and assess herbicide interaction and physiological response with combinations of glyphosate and glufosinate on common lambsquarters, velvetleaf, and giant foxtail. Greenhouse studies to determine interaction resulted in strong and persistent antagonism between glyphosate at 110 and 220 g ae ha−1and glufosinate at 20 or 40 g ae ha−1in giant foxtail, whereas only transient and reduced antagonism was noted for velvetleaf and common lambsquarters. Combining glyphosate and glufosinate increased the maximum absorption of glyphosate by 9% and 23% in velvetleaf and giant foxtail, respectively, compared with glyphosate alone. In velvetleaf, averaged over time, only 2.6% of the applied radioactivity translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 9.9% when glyphosate was applied alone. In giant foxtail, 21.6% of the [14C]glyphosate translocated out of the treated leaf when glufosinate was mixed with glyphosate compared with 52.4% when glyphosate was applied alone. Conversely, no change in the radioactive pattern of translocation was noted for common lambsquarters. These results suggest that reduced translocation of glyphosate is the physiological mechanism responsible for the antagonism observed between glyphosate and glufosinate in giant foxtail and, to a lesser extent, in velvetleaf.

Effects of Giant Foxtail (Setaria faberi) and Yellow Foxtail (Setaria pumila) Competition on Establishment and Productivity of Switchgrass

Switchgrass is a potential feedstock for cellulosic bioenergy production. Weed competition from annual grass during the establishment year can reduce switchgrass establishment and resulting productivity, but the relationship between early season grass densities and outcomes of competition are not well understood. We measured how a range of giant and yellow foxtail densities in the establishment year influenced switchgrass establishment and resulting productivity in the first production year (second year of the growing season). In two of the three site–yr more than four foxtail plants m−2reduced switchgrass plant densities below documented thresholds of establishment success. A lesser effect of foxtails in the third site–year suggested that higher switchgrass emergence rates reduced foxtail competitive ability during establishment. Effects on yield were consistent over the three site–yr. The yield (10.96 Mg ha−1± 0.77) decreased rapidly as foxtail density increased. One foxtail plant m−2reduced switchgrass yield in the first production year by 25%, and yield loss was 90% or greater at densities > 50 foxtail plants m−2. Although switchgrass can establish in the presence of foxtail competition, these weed species should be controlled to maximize yields in the first production year.

The Biology of Canadian Weeds. 141. Setaria faberi Herrm.

Setaria faberi, commonly known as giant foxtail, is an annual graminaceous weed that is native to eastern China, has colonized eastern North America and is expanding its range westward. This species is primarily self-pollinated and the only mechanism of reproduction is by seed. Adult plants may reach 2 m in height and produce over 2000 seeds per panicle. Seeds may possess non-deep physiological dormancy when freshly produced, and can form small persistent seed banks. If not controlled, S. faberi populations can cause severe yield reductions in corn and soybean crops. Several herbicides are available to provide chemical control; however, resistance to some modes of action, (ALS, ACCase, and Photosystem II) have been identified in Canada and the United States. Leaves and seeds of this species provide a food source to several species of mammals, birds, and insects. Key words: Setaria faberi, giant foxtail, growth, development, seed germination, diseases, herbicide

New records of interesting xenophytes in the Iberian Peninsula. Nuevas citas de xenófitos interesantes en la Península Ibérica.

ABSTRACT. New records of interesting xenophytes in the Iberian Peninsula. Botanical inventories in various parts of Spain mainly between 2005 and 2007 yielded numerous chorological novelties. Cyperus prolifer is probably reported for the first time in Europe. Chenopodium simplex, Dactyloctenium aegyptium, Digitaria violascens, Eragrostis frankii, Ipomoea x leucantha, Ludwigia peploides subsp. montevidensis, Malvastrum coromandelianum, Melinis repens subsp. repens, Oenothera indecora subsp. indecora, Panicum philadelphicum subsp. gattingeri and Solanum americanum are probably recorded for the first time from Spain. Crassula campestris is first cited from Portugal. New provincial records include: Abutilon grandifolium (Barcelona), Amaranthus palmeri (Lérida), Amelichloa caudata (Valencia), Anoda cristata (Huelva), Arctotheca calendula (Gerona), Asparagus setaceus (Huelva), Bidens subalternans (Huelva), Cardiospermum halicacabum (Alicante), Cenchrus incertus (Cádiz), Cestrum parqui (Barcelona), Cyperus esculentus (Huelva), Datura ferox (Huelva), Elymus elongatus subsp. ponticus (Lérida, Sevilla), Eragrostis mexicana subsp. virescens (Huelva), Eragrostis pectinacea (Huelva), Galinsoga quadriradiata (Huelva), Hydrocotyle bonariensis (Huelva), Leptochloa uninervia (Granada, Huesca), Oenothera oehlkersi (Gerona), Rumex cristatus (Gerona), Senna obtusifolia (Huelva), Setaria faberi (Huelva), S. parviflora (Huelva), Solanum elaegnifolium (Alicante), S. linnaeanum (Granada), S. physalifolium (Huelva) and Verbena litoralis var. brevibracteata (Huelva). Previous Andalusian records of Galenia secunda turned out to be in error for G. pubescens. A large majority of the cited taxa is of American origin.Key words. New records, Xenophytes, Spain.RESUMEN. Nuevas citas de xenófitos interesantes en la Península Ibérica. Diferentes campañas de herborizaciones en España entre los años 2005 -2007, han propiciado el descubrimiento de diferentes novedades corológicas para su flora. Se cita como novedad para Europa Cyperus prolifer. Son probablemente nuevas citas para España Chenopodium simplex, Dactyloctenium aegyptium, Digitaria violascens, Eragrostis frankii, Ipomoea x leucantha, Ludwigia peploides subsp. montevidensis, Malvastrum coromandelianum, Melinis repens subsp. repens, Oenothera indecora subsp. indecora, Panicum philadelphicum subsp. gattingeri y Solanum americanum. Se cita como novedad por el Portugal Crassula campestris. Se incluyen como novedades provinciales: Abutilon grandifolium (Barcelona), Amaranthus palmeri (Lérida), Amelichloa caudata (Valencia), Anoda cristata (Huelva), Arctotheca calendula (Gerona), Asparagus setaceus (Huelva), Bidens subalternans (Huelva), Cardiospermum halicacabum (Alicante), Cenchrus incertus (Cádiz), Cestrum parqui (Barcelona), Cyperus esculentus (Huelva), Datura ferox (Huelva), Elymus elongatus subsp. ponticus (Lérida, Sevilla), Eragrostis mexicana subsp. virescens (Huelva), Eragrostis pectinacea (Huelva), Galinsoga quadriradiata (Huelva), Hydrocotyle bonariensis (Huelva), Leptochloa uninervia (Granada, Huesca), Oenothera oehlkersi (Gerona), Rumex cristatus (Gerona), Senna obtusifolia (Huelva), Setaria faberi (Huelva), S. parviflora (Huelva), Solanum elaegnifolium (Alicante), S. linnaeanum (Granada), S. physalifolium (Huelva) y Verbena litoralis var. brevibracteata (Huelva). Se actualiza la nomenclatura en Andalucía de las citas previas del taxón Galenia secunda, que se cambia por Galenia pubescens, su nombre correcto. Una gran mayoría de los taxones citados son de origen americano.Palabras clave. Novedades, Xenofitos, España