scholarly journals (220) Pelargonic Acid Weed Control Parameters

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1034D-1034 ◽  
Author(s):  
Charles L. Webber ◽  
James W. Shrefler

Producers and researchers are interested in pelargonic acid (nonanoic acid) as a broad-spectrum postemergence or burn-down herbicide. Pelargonic acid is a fatty acid naturally occurring in many plants and animals, and present in many foods we consume. The objective of this research was to determine the effect of pelargonic acid concentration, adjuvants, and application timing on weed control efficacy as a burn-down herbicide. Field research was conducted at Lane, Okla. (southeast Oklahoma), during the 2005 growing season. One month prior to spraying the weed control treatments, the land was cultivated to kill the existing weeds and provide a uniform seed bed for new weed growth. The factorial weed control treatments included three application concentrations of Scythe (57.0% pelargonic acid) applied at 3%, 6.5%, and 10%; three adjuvants (none, orange oil, and non-ionic surfactant); and two application dates. All herbicide treatments were applied with an application volume of 935 L/ha to seedling weeds. The experiment had a high weed density with multiple species of grass and broadleaf weeds. Weed control across species increased as the herbicide concentrations increased from 0% to 10%. At all concentrations applied, pelargonic acid produced greater weed control for a longer time period for the broadleaf weeds than the grass weeds. Visual damage to the weeds was often apparent within a few hours after application. There was a significant increase in weed control when applied to the younger weeds. In this research, pelargonic acid was effective in controlling both broadleaf and grass weeds as a burn-down herbicide, although crabgrass was tougher to control.

2012 ◽  
Vol 26 (4) ◽  
pp. 699-707 ◽  
Author(s):  
Jared A. Hoyle ◽  
J. Scott McElroy ◽  
J. Jack Rose

Weed control by heat or flaming typically uses flames to burn small weeds, directed away from desired crops. This research studied an enclosed flaming system for weed control before turfgrass establishment. Field research trials were conducted to explore the efficacy of a PL-8750 flame sanitizer at two application timings. Treatments included various application methods of PL-8750 flame sanitizer and common thermal and chemical weed control methods. Data were weed control relative to the control treatment. Species evaluated included carpetweed, Virginia buttonweed, spotted spurge, large crabgrass, goosegrass, old world diamond-flower, cocks-comb kyllinga, and yellow nutsedge. Turfgrass establishment was not successful in summer but was successful in fall. Fall-application timing trials resulted in > 60% tall fescue establishment at 6 wk after seeding (WAS) for all treatments. Summer-application timing trials resulted in unacceptable turfgrass establishment (≤ 18%) for all evaluated turfgrass species at 6 WAS. Broadleaf and grassy weeds were better controlled compared with sedge weeds. Overall, solarization; covered, emerged-weed flaming; and double applications of covered, emerged-weed flaming were the most successful treatments. Solarization controlled carpetweed, Virginia buttonweed, spotted spurge, large crabgrass, and goosegrass > 80% at 6 WAS. Weed control across thermal treatments were equal to or greater than the comparison chemical treatment (dazomet at 389 kg ha−1). Results indicate thermal weed control has potential for reducing weed populations before turfgrass establishment.


2007 ◽  
Vol 21 (1) ◽  
pp. 186-190 ◽  
Author(s):  
Kelly A. Nelson

Field research was conducted in 2002 and 2003 to determine the effect of twin- and single-row spacing and POST glyphosate application timing on light interception, weed control, and grain yield of glyphosate-resistant corn and soybean. Row spacing did not affect light interception measured 10 to 11 wk after planting. Corn grain yield in 2002 was 1.0 Mg/ha higher in single rows compared with twin rows when averaged over glyphosate timing, but was unaffected by row spacing in 2003. Soybean grain yield was similar in 19- and 38-cm single rows, and single-row grain yield was 0.2 to 0.4 Mg/ha higher than the twin-row spacing. Corn grain yields were similar to the weed-free control when glyphosate was applied to weeds 10 to 15 cm tall in 2002 and 10 cm tall in 2003. Soybean yield was maximized by application of glyphosate to weeds 15 to 30 cm tall in 2002 and 60 cm tall in 2003.


1991 ◽  
Vol 5 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Douglas D. Buhler

Field research was conducted at Arlington, WI in 1984 and 1985 to determine the influence of application timing on weed control with atrazine and metolachlor in conservation tillage corn production systems. Early preplant treatments controlled fewer weeds than preemergence or early preplant/preemergence sequential treatments in a chisel plow system. Velvetleaf control was only 50% late in the growing season with early preplant atrazine compared with 88% with an early preplant/preemergence sequential treatment of the same amount of atrazine. In the no-till system, early preplant applications of atrazine and/or metolachlor had reduced weed control late in the growing season compared with preemergence and early preplant/preemergence sequential treatments of the same amount of herbicide. Giant foxtail control 110 d after corn planting was only 73% with an early preplant treatment compared with 99% when the same amount of herbicide was evenly divided between early preplant and preemergence applications.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Kelly A. Nelson

Autumn and early preplant N applications, sources, and placement may affect winter annual weed growth. Field research evaluated (1) the effect of different nitrogen sources in autumn and early preplant on total winter annual weed growth (2006–2010), and (2) strip-till and broadcast no-till N applied in autumn and early preplant on henbit (Lamium amplexicauleL.) growth (2008–2010) prior to a burndown herbicide application. Total winter annual weed biomass was greater than the nontreated control when applying certain N sources in autumn or early preplant for no-till corn. Anhydrous ammonia had the lowest average weed density (95 weeds m−2), though results were inconsistent over the years. Winter annual weed biomass was lowest (43 g m−2) when applying 32% urea ammonium nitrate in autumn and was similar to applying anhydrous ammonia in autumn or early preplant and the nontreated control. Henbit biomass was 28% greater when applying N in the autumn compared to an early preplant application timing. Nitrogen placement along with associated tillage with strip-till placement was important in reducing henbit biomass. Nitrogen source selection, application timing, and placement affected the impact of N on winter annual weed growth and should be considered when recommending a burndown herbicide application timing.


2012 ◽  
Vol 26 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Gregg Johnson ◽  
Fritz Breitenbach ◽  
Lisa Behnken ◽  
Ryan Miller ◽  
Tom Hoverstad ◽  
...  

There are significant concerns over the long- and short-term implications of continuous glyphosate use and potential problems associated with weed species shifts and the development of glyphosate-resistant weed species. Field research was conducted to determine the effect of herbicide treatment and application timing on weed control in glyphosate-resistant soybean. Ten herbicide treatments were evaluated that represented a range of PPI, PRE, and POST-only application timings. All herbicide treatments included a reduced rate of glyphosate applied POST. PRE herbicides with residual properties followed by (fb) glyphosate POST provides more effective control of broadleaf weed species than POST-only treatments. There was no difference in soybean yield between PRE fb POST and POST-only treatments in 2008. Conversely, PRE fb POST herbicide treatments resulted in greater yield than POST-only treatments in 2009. Using PRE fb POST herbicide tactics improves weed control and reduces the risk for crop yield loss when dealing with both early- and late-emerging annual broadleaf weed species across variable cropping environments.


1995 ◽  
Vol 9 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Calvin G. Messersmith ◽  
Steve W. Adkins

Literature concerning interactions between herbicides and insects is reviewed. Herbicides can be toxic to insects or can affect them indirectly, such as by destroying food supplies, but they usually can be used with proper application timing without affecting insects adversely. Herbicides and biocontrol insects can interact either favorably or unfavorably depending on the life cycle stage of weed and insect, effect on predatory insects, changes in food quality, mobility of the biocontrol insect, and impact of herbicides on weed growth. Thus, interactions between a biocontrol insect and herbicide can be antagonistic, additive, complementary, or synergistic. Split-plot techniques to evaluate these interactions at an early stage of insect establishment are proposed to improve weed biocontrol.


2014 ◽  
Vol 32 (1) ◽  
pp. 51-59 ◽  
Author(s):  
L.B. Tavella ◽  
P.S.L. Silva ◽  
V.R. Oliveira ◽  
P.L.O. Fernandes ◽  
R.P. Sousa

The objectives of this study were to evaluate baby corn yield, green corn yield, and grain yield in corn cultivar BM 3061, with weed control achieved via a combination of hoeing and intercropping with gliricidia, and determine how sample size influences weed growth evaluation accuracy. A randomized block design with ten replicates was used. The cultivar was submitted to the following treatments: A = hoeings at 20 and 40 days after corn sowing (DACS), B = hoeing at 20 DACS + gliricidia sowing after hoeing, C = gliricidia sowing together with corn sowing + hoeing at 40 DACS, D = gliricidia sowing together with corn sowing, and E = no hoeing. Gliricidia was sown at a density of 30 viable seeds m-2. After harvesting the mature ears, the area of each plot was divided into eight sampling units measuring 1.2 m² each to evaluate weed growth (above-ground dry biomass). Treatment A provided the highest baby corn, green corn, and grain yields. Treatment B did not differ from treatment A with respect to the yield values for the three products, and was equivalent to treatment C for green corn yield, but was superior to C with regard to baby corn weight and grain yield. Treatments D and E provided similar yields and were inferior to the other treatments. Therefore, treatment B is a promising one. The relation between coefficient of experimental variation (CV) and sample size (S) to evaluate growth of the above-ground part of the weeds was given by the equation CV = 37.57 S-0.15, i.e., CV decreased as S increased. The optimal sample size indicated by this equation was 4.3 m².


2007 ◽  
Vol 21 (4) ◽  
pp. 993-996 ◽  
Author(s):  
Andrew W. MacRae ◽  
David W. Monks ◽  
Roger B. Batts ◽  
Allan C. Thorton ◽  
Jonathan R. Schultheis

Studies were conducted in 2003 and 2004 to determine the effect of application timing and halosulfuron rate on sweetpotato yield and quality. Halosulfuron was applied 1, 2, and 4 wks after transplanting (WAP) sweetpotato in 2003, and 2, 3, and 4 WAP in 2004. Treatments within each timing included halosulfuron at 13, 26, 39, 52, and 65 g ai/ha plus a weed-free control. Combined over year, site, cultivar and rate, halosulfuron applied at 1, 2, 3, and 4 WAP stunted sweetpotato 32, 15, 11, and 14%, respectively, rated 2 wks after treatment. The stunting observed with the 1 and 2 WAP timings caused a 17 and 10% reduction in yield of No. 1 roots, respectively, compared with the weed-free control. The 3 and 4 WAP timings of halosulfuron did not reduce yield of No. 1 roots. Total yield was reduced approximately 11% at the 1, 2, and 3 WAP application timings. Halosulfuron at 4 WAP did not reduce total yield. Combined over year, site, and cultivar, halosulfuron applied at 39 g/ha did not reduce the weight of No. 1 roots or total crop yield and thus could be an effective POST option for weed control in sweetpotato.


Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 531-539 ◽  
Author(s):  
Zubeyde Filiz Arslan ◽  
Martin M. Williams ◽  
Roger Becker ◽  
Vincent A. Fritz ◽  
R. Ed Peachey ◽  
...  

Atrazine has been the most widely used herbicide in North American processing sweet corn for decades; however, increased restrictions in recent years have reduced or eliminated atrazine use in certain production areas. The objective of this study was to identify the best stakeholder-derived weed management alternatives to atrazine in processing sweet corn. In field trials throughout the major production areas of processing sweet corn, including three states over 4 yr, 12 atrazine-free weed management treatments were compared to three standard atrazine-containing treatments and a weed-free check. Treatments varied with respect to herbicide mode of action, herbicide application timing, and interrow cultivation. All treatments included a PRE application of dimethenamid. No single weed species occurred across all sites; however, weeds observed in two or more sites included common lambsquarters, giant ragweed, morningglory species, velvetleaf, and wild-proso millet. Standard treatments containing both atrazine and mesotrione POST provided the most efficacious weed control among treatments and resulted in crop yields comparable to the weed-free check, thus demonstrating the value of atrazine in sweet corn production systems. Timely interrow cultivation in atrazine-free treatments did not consistently improve weed control. Only two atrazine-free treatments consistently resulted in weed control and crop yield comparable to standard treatments with atrazine POST: treatments with tembotrione POST either with or without interrow cultivation. Additional atrazine-free treatments with topramezone applied POST worked well in Oregon where small-seeded weed species were prevalent. This work demonstrates that certain atrazine-free weed management systems, based on input from the sweet corn growers and processors who would adopt this technology, are comparable in performance to standard atrazine-containing weed management systems.


2021 ◽  
Author(s):  
◽  
Krunoslav Puškar

This thesis deals with the analysis and description of the historical and contemporary anthroponymy of the Kalnik area of the Prigorje region on the basis of both archival and field research carried out throughout a longer period of time. Since there has not been any extensive onomastic reasearch in the very area to date, our goal was to determine the influence of linguistic and extralinguistic changes in the reaserched onomastic categories. The introduction of this thesis provides the geographical, sociohistorical, demographical and linguistic context of the researched area, whereas the subsequent chapters provide a list and analysis of confirmed first names, personal and family nicknames, as well as family names of the reaserched area. First names were researched during nine time periods with a duration of five years, beginning from 1802 and ending in 2014. Because of a wide researched area, we limited our research on the anthroponymic repertoire of the city of Križevci, in which 3020 first names (1579 male and 1441 female names) were confirmed. In the 19th century, during five analysed time periods, 1519 first names were confirmed, out of which 814 male and 705 female names, which were mostly simple based on their structure (91.64%). Concerning the provenance of the first names, we established that almost all names were either Christian names or translated Christian names and that national names occur very rarely and sporadically, only in the second half of the 19th century. By comparison, in the 20th and 21st century, during the last four time periods, 1501 first names have been confirmed, out of which 765 were male and 736 female names. Concerning their structure, they turned out to be mostly compound first names in the 1946- 1950 time period (55.69%), whereas in the 2010-2014 time period they turned out to be predominantly single (97.02%). Concerning their provenance, in the 1946-1950 time period 48.39% of male and 57.58% of female national names were confirmed, whereas in the last time period male national names amount to 4.05%, and female national names to only 1.27%. Personal nicknames are a special anthroponymic category which has not been researched in the Kalnik area. Having limited our field research on 13 places throughout the area, we confirmed 288 real personal nicknames, 245 male and 43 female nicknames, of mostly simple structure (95.14%), which are still mostly used in oral and informal communication. The motivation behind the nicknames has faithfully shown us the extralinguistic reality of the researched area. The most frequent motivational group of nicknames is the one of unknown motivation (23.96%), while the other confirmed groups are nicknames motivated by a first name (12,15%), a physical characteristic of the owner (12.15%), another characteristic of the owner (11,81%), a specific word used by the owner (8.33%), an animal (6.94%), a family name (6.60%), an occupation (6.25%), an ethnonym or toponym (4.51%), a family or social role (2.78%), a professional designation (1.38%), food (1.04%), a name for a plant (1.04%), a subject (0.69%), and another nickname (0.35%). The high frequency of nicknames of unknown motivation shows us the importance of future research of this anthroponymic category because, due to the passage of time, it is difficult to determine the real motivation of every nickname. We came to the same conclusion during our research of family nicknames, another specific anthroponymic category, still quite present in the Kalnik area. Having limited our field research on 12 places throughout the wide researched area, we managed to confirm 173 real family nicknames, whose designated motivational groups provided us with important sociolinguistic pieces of information. Concerning their structure, the majority of family nicknames turned out to be simple (N = 129), whereas concerning their motivation, the majority of family nicknames were of unknown motivation (N = 33). Other motivational groups were the following: a first name (N = 27), an occupation (N = 27), a family name (N = 25), a personal nickname (N = 22), a certain characteristic (N = 13), an ethnonym (N = 10), a toponym (N = 6), a certain subject (N = 6), and an animal (N = 4). All these mentioned different anthroponymic categories (first names, personal and family nicknames) can be confirmed profusely in the last anthroponymic category researched and analysed in this thesis – family names. Having employed the criterion of their minimum continuity of 100 years in the researched area, we have managed to confirm 1360 family names with centuries old continuity, since the 14th century to this very day. With this criterion we also managed to reduce a significant number of over 3000 family names with mostly no continuity, as well as to confirm those last names which had left their trace in the researched area. Of course, not all family names confirmed by this criterion are necessarily connected to the researched area, but are only detected in it. Out of 1360 confirmed family names, we succeeded in determining 189 family names which occur exclusively or mostly in the researched area, 100 family names which do not occur in contemporary anthroponymy of the area, and 97 family names which could also become extinguished in near future. Concerning their structure, the majority of all family names occur without a suffix (N = 681). All the confirmed family names were analysed according to their structure and motivation and listed in our Lexicon of family names at the end of this very thesis.


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