scholarly journals Efficacy of preemergence herbicides on three annual grass weeds in different soils

2009 ◽  
Vol 62 ◽  
pp. 356-362
Author(s):  
T.K. James ◽  
A. Rahman

Pot experiments evaluated the efficacy of several preemergence herbicides on three annual grasses that are major problem weeds in most maize growing regions Herbicides evaluated included alachlor metolachlor dimethenamid two formulations of acetochlor and proprietary mixes of acetochlor with atrazine or metribuzin Pots were filled with soil collected from the top 10 cm of seven maize (Zea mays) fields with different cropping histories and seeded with test grasses Herbicides were applied immediately after sowing with a precision glasshouse sprayer Additional seeds were sown at 2weekly intervals for 8 weeks Seedlings were counted 2 weeks after each planting Metolachlor was most effective in controlling summer grass (Digitaria sanguinalis) and rough bristle grass (Setaria verticillata) All herbicides were less effective against the large seeded broom corn millet (Panicum miliaceum) than the other grasses All the herbicides except metolachlor were less effective in soils with a long history of maize growing

2010 ◽  
Vol 63 ◽  
pp. 66-71
Author(s):  
A. Rahman ◽  
T.K. James

The efficacy of several preemergence herbicides on barnyard grass (Echinochloa crusgalli) smooth witchgrass (Panicum dichotomiflorum) and yellow bristle grass (Setaria pumila) was investigated in different soils in pot experiments These soils were collected from the top 10 cm of seven maize fields with different cropping histories The herbicides used were dimethanamid alachlor metolachlor two formulations of acetochlor and proprietary mixes of acetochlor with atrazine or metribuzin Plastic pots filled with soil were seeded with 10 seeds of individual grass species and herbicide treatments were then applied with a precision pot sprayer A further 10 seeds of the same grass species were sown at 2weekly intervals for 8 weeks to test the duration of residual weed control The number of emerged seedlings was counted in each pot at 2 weeks after each planting Metolachlor was the most effective chemical for controlling E crusgalli and P dichotomiflorum For S pumila similar levels of control were achieved by all treatments evaluated Generally all the herbicides were less effective in soils with a long history of maize growing where up to three times more seedlings emerged than in soils with only 12 years of maize cropping


2002 ◽  
Vol 42 (8) ◽  
pp. 1033 ◽  
Author(s):  
A. M. Ridley ◽  
A. L. Avery ◽  
R. N. Oram ◽  
J. Hunter ◽  
J. B. Shovelton ◽  
...  

Persistence of an aluminium (Al)-tolerant phalaris F1 hybrid (Siro 1146 Phalaris aquatica × P.�arundinacea) was compared with that of 3 more Al-sensitive phalaris (P. aquatica L.) lines (cv. Australian and the progenitors of cvv. Sirosa and Sirolan) at 2 sites (Strathbogie and Baddaginnie) in north-eastern Victoria with strongly acidic soils 20 years after sowing. Soil pHCa and extractable aluminium (AlCa) were also measured to 1 m depth under Siro 1146 and annual grass pasture at each site. All grass treatments contained volunteer subclover. Siro 1146 persisted better than the other lines (P<0.05) at Strathbogie where the soil contained high AlCa concentrations down to 50 cm depth. Soils should be sampled and tested to at least this depth to determine their suitability for phalaris. At this site Australian phalaris persisted better than the progenitors of Sirosa and Sirolan (P<0.01), probably because Australian has more spreading ability and tolerance of set stocking than the winter active lines. At Baddaginnie, the soil contained lower concentrations of AlCa below 20 cm depth than at Strathbogie and persistence of the 3 Al sensitive phalaris lines was good despite the lower rainfall. The less drought-tolerant Siro�1146 persisted poorly at Baddaginnie, but had high ground cover due to high lateral spread of the survivors. At Strathbogie, the 10–20 cm layer of soil under Siro 1146 had a higher pHCa and lower AlCa than that under the other 4 phalaris and the annual grass treatments. Soil under Siro 1146 also had higher pHCa and lower AlCa down to 40�cm�depth compared with the annual grass treatment, the differences being significant in the 20–30 cm layer. These differences were reversed at 50–100 cm, but only the effect on Al was significant. Although soils were not sampled at the beginning of the experiment, adequate replication and randomisation of the grass treatments showed that it was statistically improbable for observed final differences to be due to initial soil differences. The final differences may be due to greater amounts of nitrate being taken up from the upper layers by Siro 1146 over its long growing season compared with the annual grasses, leading to greater nitrate leaching from the upper layers and greater nitrate uptake from lower layers under the annuals (i.e. spatial separation of acid generation and consumption processes within the profile). Another possible reason for the greater acidification below 50 cm by the perennial is that its roots may have taken up more cations in this zone. Because of rising concern in some sectors of the public about the off-site, environmental effects of agriculture, the future role of more acid-tolerant phalaris cultivars growing near native vegetation in the high rainfall zone is discussed.


Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 287-290 ◽  
Author(s):  
Gail Ezra ◽  
Jack H. Dekker ◽  
Gerald R. Stephenson

Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane] is a potent synergist of atrazine for postemergence control of weeds such as giant foxtail (Setaria faberiHerrm. ♯ SETFA) and large crabgrass [Digitaria sanguinalis(L.) Scop. ♯ DIGSA]. We determined whether: a) tridiphane could syngergize the activity of other herbicides known to be detoxified via enzymatic conjugation to glutathione, and b) differential toxicities of the synergized herbicides could provide control of proso millet (Panicum miliaceumL. ♯ PANMI) in corn (Zea maysL. “PAG SXIII”). Four herbicides were used in this study: EPTC (S-ethyl dipropylthiocarbamate), atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], CDAA (N-N-diallyl-2-chloroacetamide), and alachlor [2-chloro-2’,6’-diethyl-N-(methoxymethyl) acetanilide]. Herbicides and herbicide-synergist combinations were applied postemergence. In corn, tridiphane synergized the activity of EPTC at 2 and 4 kg ai/ha, causing 22 to 25% growth reduction. Atrazine was ineffective and CDAA only slightly effective in combination with tridiphane in causing growth reduction. However, alachlor was markedly synergized by tridiphane at both 2 and 4 kg ai/ha, resulting in 36 to 54% growth reduction compared with plants treated with herbicides alone. Proso millet followed a similar trend to corn: EPTC and alachlor were effectively synergized by tridiphane, while atrazine and CDAA were ineffective. Importantly, however, the rates of herbicide used for proso millet control were much lower than those used for corn. Our data suggest that tridiphane used in combination with EPTC or alachlor could provide improved control of proso millet in corn.


Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 340-344 ◽  
Author(s):  
J. Peyton Doub ◽  
Henry P. Wilson ◽  
Thomas E. Hines ◽  
Kriton K. Hatzios

Consecutive annual applications of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] were made to continuous no-till corn (Zea maysL. ‘Pioneer 3184’ in 1982 and 1983, ‘Pioneer 3744’ in 1984, and ‘Pioneer 3378’ in 1985 to 1987). In a 5-yr study, control of the dominant annual grass species, large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA], by alachlor declined to less than 50% by the fifth year. Control of large crabgrass by metolachlor remained greater than 80% throughout the study but metolachlor allowed the establishment of a greater fall panicum (Panicum dichotomiflorumMichx. # PANDI) population in this and an additional 3-yr study than in chloroacetamide-free checks. In the 3-yr study in which giant foxtail (Setaria faberiHerrm. # SETFA) was dominant, annual applications of metolachlor and a microencapsulated formulation of alachlor provided better control in the second year than the emulsifiable concentrate formulation of alachlor, but formulation differences diminished in the third year.


2007 ◽  
Vol 21 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Robert J. Richardson ◽  
Henry P. Wilson ◽  
Thomas E. Hines

Field studies were conducted in 1999, 2000, and 2001 to evaluate weed control and cotton response from PRE herbicides followed by (fb) trifloxysulfuron POST. In the first study, trifloxysulfuron at 3.8, 7.5, or 15 gai/ha was applied POST with or without pendimethalin at 690 gai/ha applied PRE in a factorial treatment arrangement. Visible crop injury occurred after all trifloxysulfuron applications, but injury was not affected by application of pendimethalin PRE. Cotton injury was 19 to 22% 7 d after POST treatment (DAT) from trifloxysulfuron at 3.8 to 15 g/ha but was 5 to 12% 28 DAT. Trifloxysulfuron controlled smooth pigweed, common ragweed, and common cocklebur, but spurred anoda, large crabgrass, goosegrass, and stinkgrass were not controlled by trifloxysulfuron. Morningglory species (tall morningglory, ivyleaf morningglory, and pitted morningglory) control with trifloxysulfuron at 7.5 and 15 g/ha was at least 79%, whereas velvetleaf was controlled 66% over all years. In a second study, clomazone, pendimethalin, pendimethalin plus fluometuron, pyrithiobac, or flumioxazin were applied PRE fb 7.5 g/ha trifloxysulfuron POST. Cotton injury from PRE herbicides fb trifloxysulfuron was 13 to 39% 7 DAT. Spurred anoda control exceeded 54% only with treatments that included flumioxazin or pyrithiobac PRE. Common lambsquarters, common cocklebur, and morningglory species were controlled at least 75% with all treatments that included trifloxysulfuron POST, whereas pendimethalin and clomazone usually controlled annual grasses. In both studies, the application of pendimethalin PRE controlled annual grass species and improved control of smooth pigweed and common lambsquarters over that controlled by trifloxysulfuron POST without a PRE herbicide.


Author(s):  
Colby Dickinson

In his somewhat controversial book Remnants of Auschwitz, Agamben makes brief reference to Theodor Adorno’s apparently contradictory remarks on perceptions of death post-Auschwitz, positions that Adorno had taken concerning Nazi genocidal actions that had seemed also to reflect something horribly errant in the history of thought itself. There was within such murderous acts, he had claimed, a particular degradation of death itself, a perpetration of our humanity bound in some way to affect our perception of reason itself. The contradictions regarding Auschwitz that Agamben senses to be latent within Adorno’s remarks involve the intuition ‘on the one hand, of having realized the unconditional triumph of death against life; on the other, of having degraded and debased death. Neither of these charges – perhaps like every charge, which is always a genuinely legal gesture – succeed in exhausting Auschwitz’s offense, in defining its case in point’ (RA 81). And this is the stance that Agamben wishes to hammer home quite emphatically vis-à-vis Adorno’s limitations, ones that, I would only add, seem to linger within Agamben’s own formulations in ways that he has still not come to reckon with entirely: ‘This oscillation’, he affirms, ‘betrays reason’s incapacity to identify the specific crime of Auschwitz with certainty’ (RA 81).


2017 ◽  
Vol 39 (2) ◽  
pp. 265-276 ◽  
Author(s):  
Kas Saghafi

In several late texts, Derrida meditated on Paul Celan's poem ‘Grosse, Glühende Wölbung’, in which the departure of the world is announced. Delving into the ‘origin’ and ‘history’ of the ‘conception’ of the world, this paper suggests that, for Derrida, the end of the world is determined by and from death—the death of the other. The death of the other marks, each and every time, the absolute end of the world.


2019 ◽  
Vol 188 (1) ◽  
pp. 95-146
Author(s):  
Martin Bohatý ◽  
Dalibor Velebil

Adalbert Wraný (*1836, †1902) was a doctor of medicine, with his primary specialization in pediatric pathology, and was also one of the founders of microscopic and chemical diagnostics. He was interested in natural sciences, chemistry, botany, paleontology and above all mineralogy. He wrote two books, one on the development of mineralogical research in Bohemia (1896), and the other on the history of industrial chemistry in Bohemia (1902). Wraný also assembled several natural science collections. During his lifetime, he gave to the National Museum large collections of rocks, a collection of cut precious stones and his library. He donated a collection of fossils to the Geological Institute of the Czech University (now Charles University). He was an inspector of the mineralogical collection of the National Museum. After his death, he bequeathed to the National Museum his collection of minerals and the rest of the gemstone collection. He donated paintings to the Prague City Museum, and other property to the Klar Institute of the Blind in Prague. The National Museum’s collection currently contains 4 325 samples of minerals, as well as 21 meteorites and several hundred cut precious stones from Wraný’s collection.


2019 ◽  
Vol 1 (1) ◽  
pp. 5-14
Author(s):  
Carlos Alvaréz Teijeiro

Emmanuel Lévinas, the philosopher of ethics par excellence in the twentieth century, and by own merit one of the most important ethical philosophers in the history of western philosophy, is also the philosopher of the Other. Thereby, it can be said that no thought has deepened like his in the ups and downs of the ethical relationship between subject and otherness. The general objective of this work is to expose in a simple and understandable way some ideas that tend to be quite dark in the philosophical work of the author, since his profuse religious production will not be analyzed here. It is expected to show that his ideas about the being and the Other are relevant to better understand interpersonal relationships in times of 4.0 (re)evolution. As specific objectives, this work aims to expose in chronological order the main works of the thinker, with special emphasis on his ethical implications: Of the evasion (1935), The time and the Other (1947), From the existence to the existent (1947), Totality and infinity: An essay on exteriority (1961) and, last, Otherwise than being, or beyond essence (1974). In the judgment of Lévinas, history of western philosophy starting with Greece, has shown an unusual concern for the Being, this is, it has basically been an ontology and, accordingly, it has relegated ethics to a second or third plane. On the other hand and in a clear going against the tide movement, our author supports that ethics should be considered the first philosophy and more, even previous to the proper philosophize. This novel approach implies, as it is supposed, that the essential question of the philosophy slows down its origin around the Being in order to inquire about the Other: it is a philosophy in first person. Such a radical change of perspective generates an underlying change in how we conceive interpersonal relationships, the complex framework of meanings around the relationship Me and You, which also philosopher Martin Buber had already spoken of. As Lévinas postulates that ethics is the first philosophy, this involves that the Other claims all our attention, intellectual and emotional, to the point of considering that the relationship with the Other is one of the measures of our identity. Thus, “natural” attitude –husserlian word not used by Lévinas- would be to be in permanent disposition regarding to the meeting with the Other, to be in permanent opening state to let ourselves be questioned by him. Ontology, as the author says, being worried about the Being, has been likewise concerned about the Existence, when the matter is to concern about the particular Existent that every otherness supposes for us. In conclusion it can be affirmed that levinasian ethics of the meeting with the Other, particular Face, irreducible to the assumption, can contribute with an innovative looking to (re)evolving the interpersonal relationships in a 4.0 context.


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