Search

The objective of this study was to evaluate the effectiveness of synthetic auxins in the control of Conyza sumatrensis in mixtures for use in the first application, and the effectiveness of burndown herbicides alone or in mixtures for use in the second application, in soybean pre-sowing. Experiment 1 consisted of auxin herbicides (fluroxypyr or dicamba) in mixtures with herbicides (glyphosate, glufosinate, saflufenacil, carfentrazone, and chlorimuron) used for the first application in pre-sowing. Experiment 2 consisted of burndown herbicides (diquat, glufosinate, glyphosate, chlorimuron, saflufenacil, and carfentrazone), alone or at mixtures, used for sequential application in pre-sowing. For the first application, the effectiveness of glyphosate + dicamba or fluroxypyr was low and must be complemented by the addition of a PPO-inhibiting herbicide, mainly saflufenacil. The mixture of glufosinate, instead of glyphosate, with synthetic auxin was more effective, even increasing with the addition of saflufenacil. For the second application, with burndown herbicides, glufosinate was superior and effective when mixed with saflufenacil. For the first application in soybean pre-sowing, glyphosate or glufosinate + synthetic auxin + saflufenacil are effective for the control of C. sumatrensis. For the second application, glufosinate at mixtures is effective in controlling C. sumatrensis. [ABSTRACT FROM AUTHOR]

Diquat, glufosinate and the combination of the latter with carfentrazone or saflufenacil are believed to be as effective for pre-harvest desiccation of soybean plants as paraquat. This work was developed with the objective of evaluating the efficacy of paraquat, diquat, and glufosinate alone or at mixtures of carfentrazone or saflufenacil in pre-harvest desiccation of soybean. Soybean defoliation, maturity and yield were evaluated. Similar efficacy was observed between glufosinate and paraquat in soybean defoliation and maturity, in addition to a greater flexibility of use, in which it could be an anticipator and standardizing agent of the harvest. The application of diquat (200 g of active ingredient [a.i.] ha-1 ), paraquat (200 g a.i. ha-1 ) or glufosinate (400 or 500 g a.i. ha-1 ) was effective for pre-harvest desiccation of soybean at the R7.2 stage. As well, it was observed promising results for application of glufosinate + saflufenacil (300 + 24.5 g a.i. ha-1 ), glufosinate + carfentrazone (200 + 25 g a.i. ha-1 ), glufosinate + saflufenacil (200 + 35 g a.i. ha-1 ). Diquat and glufosinate can replace paraquat in pre-harvest desiccation of soybean plants, and glufosinate also provide greater management flexibility, in anticipating the harvest. [ABSTRACT FROM AUTHOR]

The objective was to evaluate the production components of soybean and the physiological quality of seeds according to the application of subdoses of herbicides at the reproductive stage of healthy plants. The treatments consisted of the application of glyphosate (122.5 g acid equivalent [ae] ha-1), chlorimuron (1.75 g active ingredient [ai] ha-1), 2,4-D (134 g ae ha-1), fomesafen (60 g ai ha-1), glufosinate (55 g ai ha-1), paraquat (35 g ai ha-1), and control (no application). The chlorophyll index, agronomic performance, and physiological quality of seeds were evaluated. Glyphosate, chlorimuron, fomesafen, or glufosinate resulted in an increase in soybean plant height. Chlorimuron increased yield compared to the control. Paraquat or glufosinate, despite the injury, did not reduce yield, but the application of these herbicides is not recommended to stimulate plant development, given the potential for injury. The 2,4-D was the only one that caused a reduction in the physiological quality of soybean seeds. [ABSTRACT FROM AUTHOR]

Although genetic transformation in Glycine max has been intensively investigated, the process remains ineffective. In the present work, for the first time, the in vitro selection of transgenic lines of soybean variety Incasoy-27 is addressed. From somatic embryos transformed with Agrobacterium tumefaciens strain EHA105, the regeneration of three lines of supposedly transformed plants that showed resistance to phosphinothricin 6.0 mg l-1 was achieved. GUS histochemical analysis demonstrated stable expression of the uidA gene in leaves of two plant lines. Subsequently, the presence of the bar and uidA genes in two regenerated lines was confirmed with the polymerase chain reaction; while in the third line the band referring to the uidA gene was found but it was not possible to demonstrate the presence of the bar gene. In conclusion, is possible to in vitro select transgenic lines of soybean variety Incasoy-27, with expression of the uidA and bar genes in the genome of the transformed plants and 0.30% efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)