5 results
Impact of reduced rates of 2,4-D and glyphosate on sweetpotato growth and yield
- Thomas M. Batts, Donnie K. Miller, James L. Griffin, Arthur O. Villordon, Daniel O. Stephenson IV, Kathrine M. Jennings, Sushila Chaudhari, David C. Blouin, Josh T. Copes, Tara P. Smith
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- Journal:
- Weed Technology / Volume 34 / Issue 5 / October 2020
- Published online by Cambridge University Press:
- 08 June 2020, pp. 631-636
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Commercialization of 2,4-D–tolerant crops is a major concern for sweetpotato producers because of potential 2,4-D drift that can cause severe crop injury and yield reduction. A field study was initiated in 2014 and repeated in 2015 to assess impacts of reduced rates of 2,4-D, glyphosate, or a combination of 2,4-D with glyphosate on sweetpotato. In one study, 2,4-D and glyphosate were applied alone and in combination at 1/10, 1/100, 1/250, 1/500, 1/750, and 1/1,000 of anticipated field use rates (1.05 kg ha−1 for 2,4-D and 1.12 kg ha−1 for glyphosate) to ‘Beauregard’ sweetpotato at storage root formation (10 days after transplanting [DAP]). In a separate study, all these treatments were applied to ‘Beauregard’ sweetpotato at storage root development (30 DAP). Injury with 2,4-D alone or in combination with glyphosate was generally equal or greater than with glyphosate applied alone at equivalent herbicide rates, indicating that injury is attributable mostly to 2,4-D in the combination. There was a quadratic increase in crop injury and quadratic decrease in crop yield (with respect to most yield grades) with increased rate of 2,4-D applied alone or in combination with glyphosate applied at storage root development. However, neither the results of this relationship nor of the significance of herbicide rate were observed on crop injury or sweetpotato yield when herbicide application occurred at storage root formation, with a few exceptions. In general, crop injury and yield reduction were greatest at the highest rate (1/10×) of 2,4-D applied alone or in combination with glyphosate, although injury observed at lower rates was also a concern after initial observation by sweetpotato producers. However, in some cases, yield reduction of U.S. no.1 and marketable grades was also observed after application of 1/250×, 1/100×, or 1/10× rates of 2,4-D alone or with glyphosate when applied at storage root development.
Impact of reduced rates of dicamba and glyphosate on sweetpotato growth and yield
- Thomas M Batts, Donnie K. Miller, James L. Griffin, Arthur O. Villordon, Daniel O Stephenson IV, Kathrine M. Jennings, Sushila Chaudhari, David C. Blouin, Josh T. Copes, Tara P. Smith
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- Journal:
- Weed Technology / Volume 35 / Issue 1 / February 2021
- Published online by Cambridge University Press:
- 19 May 2020, pp. 27-34
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A major concern of sweetpotato producers is the potential negative effects from herbicide drift or sprayer contamination events when dicamba is applied to nearby dicamba-resistant crops. A field study was initiated in 2014 and repeated in 2015 to assess the effects of reduced rates of N,N-Bis-(3-aminopropyl)methylamine (BAPMA) or diglycloamine (DGA) salt of dicamba, glyphosate, or a combination of these individually in separate trials with glyphosate on sweetpotato. Reduced rates of 1/10, 1/100, 1/250, 1/500, 1/750, and 1/1,000 of the 1× use rate of each dicamba formulation at 0.56 kg ha−1, glyphosate at 1.12 kg ha−1, and a combination of the two at aforementioned rates were applied to ‘Beauregard’ sweetpotato at storage root formation (10 d after transplanting) in one trial and storage root development (30 d after transplanting) in a separate trial. Injury with each salt of dicamba (BAPMA or DGA) applied alone or with glyphosate was generally equal to or greater than glyphosate applied alone at equivalent rates, indicating that injury is most attributable to the dicamba in the combination. There was a quadratic increase in crop injury and a quadratic decrease in crop yield (with respect to most yield grades) observed with an increased herbicide rate of dicamba applied alone or in combination with glyphosate applied at storage root development. However, with a few exceptions, neither this relationship nor the significance of herbicide rate was observed on crop injury or sweetpotato yield when herbicide application occurred at the storage root formation stage. In general, crop injury and yield reduction were greatest at the highest rate (1/10×) of either salt of dicamba applied alone or in combination with glyphosate, although injury observed at lower rates would be cause for concern after initial observation by sweetpotato producers. However, in some cases yield reduction of No.1 and marketable grades was observed following 1/250×, 1/100×, or 1/10× application rates of dicamba alone or with glyphosate when applied at storage root development.
In-field bioassay to investigate the persistence of imazaquin and pyrithiobac
- M. Cade Smith, David R. Shaw, Donnie K. Miller
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- Journal:
- Weed Science / Volume 53 / Issue 1 / February 2005
- Published online by Cambridge University Press:
- 20 January 2017, pp. 121-129
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Pyrithiobac and imazaquin are persistent herbicides used in the midsouthern region of the United States. Certain rotational crops are extremely sensitive to each herbicide. Field studies were established near Brooksville, MS, and St. Joseph, LA, to examine crop injury from the previous year's application of pyrithiobac and imazaquin. In Mississippi, 690 g ai ha−1 of each herbicide was applied as a preplant-incorporated carryover treatment. The subsequent year, pyrithiobac-treated areas were planted with soybean, corn, and grain sorghum. Imazaquin-treated areas were planted with cotton, corn, and grain sorghum. In plots adjacent to the carryover treatment, pyrithiobac or imazaquin was applied at rates ranging from 0 to 173 g ha−1 as in-field bioassay plots. In Louisiana, pyrithiobac was applied at 70 and 240 g ha−1 as a postdirected broadcast layby treatment in cotton. The subsequent spring, pyrithiobac-treated areas were planted to corn. Assay rates of pyrithiobac ranging from 0 to 140 g ha−1 were established in areas adjacent to the carryover treatment. Grain sorghum was most sensitive to pyrithiobac soil residues, followed by corn and then soybean. Cotton was the most sensitive crop to imazaquin soil residues, followed by corn and then grain sorghum. Residual amounts of pyrithiobac and imazaquin were approximately 15 and 24 g ha−1, respectively. The approximated half-life of pyrithiobac and imazaquin was 61 and 71 d, respectively. Pyrithiobac applied at 280 g ha−1 as a layby treatment the preceding year injured corn and reduced yields in 1 of 2 yr. Pyrithiobac at 70 g ha−1 did not affect corn in either year. The difference in persistence between the 2 yr was attributed to reduced precipitation and lower soil temperatures in the year with observed carryover. Injury and yield reduction observed in the second year of the study correspond to an approximate pyrithiobac half-life of 60 d.
Establishing Priorities Among Multiple Management Goals
- Donnie Smith, Daniel F. Capstick
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- Journal:
- Journal of Agricultural and Applied Economics / Volume 8 / Issue 2 / December 1976
- Published online by Cambridge University Press:
- 28 April 2015, pp. 37-43
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If inferences from research are to be correct, economists, research workers and extension specialists should distinguish between adjustment recommendations for an individual farmer with his unique set of values as opposed to recommendations for a hypothetical group of farmers. Too often, economic analyses are based on the implied assumption that all individuals fit a general definition of the economic man whose one objective is to maximize profits. A single goal, such as profit maximization, is often used to derive the “otpimum” plan because the planning model is operational and is assumed to provide an analytical approximation of firm behavior. Other goals may be relevant to the firm's decision-maker, and economists generally recognize that multiple goals are important in making business decisions. Consequently, single goal models are not always a realistic approach to the decision process and may not provide the farmer with an acceptable solution.
Contributors
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- By Francesco Acerbi, Ayca Akgoz, Matthew R. Amans, Ramsey Ashour, Mohammed Ali Aziz-Sultan, H. Hunt Batjer, Donnie Bell, Bernard R. Bendok, Giovanni Broggi, Morgan Broggi, Charles A. Bruno, Steven D. Chang, In Sup Choi, Omar Choudhri, Douglas J. Cook, William P. Dillon, Peter Dirks, Rose Du, Travis M. Dumont, Tarek Y. El Ahmadieh, Najib E. El Tecle, Mohamed Samy Elhammady, Paolo Ferroli, Alana M. Flexman, John C. Flickinger, Kai U. Frerichs, Sasikhan Geibprasert, Adrian W. Gelb, Y. Pierre Gobin, Bradley A. Gross, Seunggu J. Han, Tomoki Hashimoto, Juha Hernesniemi, Roberto C. Heros, Steven W. Hetts, Randall T. Higashida, Joshua A. Hirsch, Nikolai J. Hopf, L. Nelson Hopkins, Maziyar A. Kalani, M. Yashar S. Kalani, Hideyuki Kano, Syed Aftab Karim, Robert M. Koffie, Douglas S. Kondziolka, Timo Krings, Aki Laakso, Giuseppe Lanzino, Michael T. Lawton, Elad I. Levy, L. Dade Lunsford, Adel M. Malek, Michael P. Marks, George A. C. Mendes, Philip M. Meyers, Jacques Morcos, Nitin Mukerji, Christian Musahl, Ludmila Pawlikowska, Matthew B. Potts, Ross Puffer, James D. Rabinov, Jonathan J. Russin, Mina G. Safain, Duke Samson, Marco Schiariti, R. Michael Scott, Jason P. Sheehan, Paul Singh, Edward R. Smith, Scott G. Soltys, Robert F. Spetzler, Gary K. Steinberg, Philip E. Stieg, Hua Su, Karel terBrugge, Kiron Thomas, Tarik Tihan, Babu Welch, Jonathan White, H. Richard Winn, Chun-Po Yen, Jacky T. Yeung, Byron Yip, Samer G. Zammar
- Edited by Robert F. Spetzler, Douglas S. Kondziolka, Randall T. Higashida, University of California, San Francisco, M. Yashar S. Kalani
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- Book:
- Comprehensive Management of Arteriovenous Malformations of the Brain and Spine
- Published online:
- 05 January 2015
- Print publication:
- 08 January 2015, pp x-xiv
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