Seletividade de herbicidas sobre milho EnList
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Data
2019-08-26
Autores
Giovanelli, Bruno Flaibam
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Universidade Estadual Paulista (Unesp)
Resumo
A tecnologia EnList foi desenvolvida pela empresa Corteva Agriscience, e permite a aplicação dos herbicidas 2,4-D e haloxyfop-methyl sobre o milho, devido à presença do gene aad-1, além da resistência ao glyphosate e amônio glufosinato. O objetivo deste trabalho foi avaliar a seletividade de diferentes herbicidas sobre a cultura do milho com a tecnologia EnList. Os experimentos foram conduzidos em campo e casa de vegetação. Os herbicidas aplicados foram: haloxyfop-methyl, 2,4-D, e glyphosate. Os ensaios realizados em casa-de-vegetação foram organizados em delineamento inteiramente casualisado, constituídos por cinco repetições. Os herbicidas foram aplicados em pós-emergência (V4), e obteve-se as seguintes variáveis: taxa de transporte de elétrons do Fotossistema II (Electron Transport Rate - ETR), injúria visual, e altura aos 7, 14, 21 e 28 dias após aplicação (DAA). Aos 28 DAA, foram coletadas as plantas para a obtenção da massa seca final. Os experimentos 1 e 2 corresponderam a aplicação de todos os herbicidas acima, tanto de forma isolada como em misturas. Neste mesmo estudo, foi instalado um ensaio adicional a campo para testar os parâmetros produtivos, porém com a adição de amônio-glufosinato. Os demais experimentos constituíram-se de ensaios de dose-resposta para cada um dos três herbicidas estudados, comparando-se um material com a tecnologia EnList, e sua isolinha sem o gene aad-1. Portanto, os ensaios 3 e 4 se referiram a aplicação de doses crescentes de 2,4-D, que foram: 0; 456; 912; 1.824; 3.648 e 7.296 g e.a ha-1. Os experimentos 5 e 6 corresponderam às seguintes doses de haloxyfop-methyl: 0; 63; 126; 252; 504 e 1.008 g i.a ha-1 e além das variáveis acima, analisou-se o teor total de lipídeos, através de análises de extrato etéreo. No experimento 7, foram testadas seis doses de glyphosate (0; 480; 960; 1.920; 3.840; 5.760 g e.a ha-1) sobre os materiais. No primeiro estudo, a aplicação dos tratamentos não resultou em injúrias visuais ou redução dos demais parâmetros, como a produtividade. Nos experimentos envolvendo 2,4-D, observou-se uma redução da ETR da isolinha, aos 21 e 28 DAA para as doses mais elevadas, com decréscimo de altura e massa seca. Com relação ao haloxyfop-methyl, não houve reduções em nenhuma das variáveis para as plantas resistentes. Porém, foram observadas reduções >50% da ETR para a isolinha, aos 3 DAA, assim como diminuição do teor de extrato etéreo para este material. No experimento envolvendo glyphosate, não foram observadas diferenças significativas entre as variáveis. A tecnologia EnList é segura quanto aos herbicidas aplicados, nas doses de bula recomendadas.
The EnList traits were developed by Corteva Agriscience, and provide both 2,4-D and haloxyfop-methyl resistance for maize due to the aad-1 gene. In addition, it presents glyphosate and ammonium-glufosinate resistance. The objective of this research was to assess the selectivity of different herbicides for EnList maize. The experiments were conducted both in the field and in greenhouse. The herbicides applied were: haloxyfop-methyl, 2,4-D, and glyphosate. The greenhouse treatments were arranged in a completely randomized design and consisted of five replications. The herbicides were applied in post-emergence (V4), and the variables obtained were: Electron transport rate of photosystem II (Electron Transport Rate - ETR), visual injury, and plant height at 7, 14, 21 and 28 days after application (DAA). At 28 DAA, the plants were cut for obtaining the final dry mass. The experiments 1 and 2 corresponded to the application of all the herbicides cited above, both alone and in mixtures. In this same study, an additional field trial was conducted for testing the production parameters, adding ammonium-glufosinate to some treatments. The other experiments consisted of dose-response assays for each of the herbicides cited, comparing a material with the EnList technology, and its isoline (non aad-1 material). The experiments 3 and 4 referred to increasing doses of 2,4-D application, which were: 0; 456; 912; 1.824; 3,648 and 7,296 g a.e ha-1. Experiments 5 and 6 corresponded to the following doses of haloxyfop-methyl: 0; 63; 126; 252; 504 and 1.008 g a.i ha-1, and in addition to the variables above, the total lipid content was analyzed by ethereal extract analysis. In experiment 7, six doses of glyphosate (0; 480; 960; 1,920; 3,840; 5,760 g a.a ha-1) were tested for each material. In the first study, the applications did not result on visual injuries or decrease of the other parameters, such as yield. In the experiments involving 2,4-D herbicide, there was a lower ETR at 21 and 28 DAA for the higher doses in the isoline, affecting plant height and dry mass. Haloxyfop-methyl applications did not reduce any of the variables for aad-1 transformed plants. However, reductions >50% of the ETR were observed for the isoline at 3 DAA, and hence a decrease in the ethereal extract. For the glyphosate experiment, no significant differences were observed. The EnList trait is safe for these herbicides when used the recommended labeled rates.
The EnList traits were developed by Corteva Agriscience, and provide both 2,4-D and haloxyfop-methyl resistance for maize due to the aad-1 gene. In addition, it presents glyphosate and ammonium-glufosinate resistance. The objective of this research was to assess the selectivity of different herbicides for EnList maize. The experiments were conducted both in the field and in greenhouse. The herbicides applied were: haloxyfop-methyl, 2,4-D, and glyphosate. The greenhouse treatments were arranged in a completely randomized design and consisted of five replications. The herbicides were applied in post-emergence (V4), and the variables obtained were: Electron transport rate of photosystem II (Electron Transport Rate - ETR), visual injury, and plant height at 7, 14, 21 and 28 days after application (DAA). At 28 DAA, the plants were cut for obtaining the final dry mass. The experiments 1 and 2 corresponded to the application of all the herbicides cited above, both alone and in mixtures. In this same study, an additional field trial was conducted for testing the production parameters, adding ammonium-glufosinate to some treatments. The other experiments consisted of dose-response assays for each of the herbicides cited, comparing a material with the EnList technology, and its isoline (non aad-1 material). The experiments 3 and 4 referred to increasing doses of 2,4-D application, which were: 0; 456; 912; 1.824; 3,648 and 7,296 g a.e ha-1. Experiments 5 and 6 corresponded to the following doses of haloxyfop-methyl: 0; 63; 126; 252; 504 and 1.008 g a.i ha-1, and in addition to the variables above, the total lipid content was analyzed by ethereal extract analysis. In experiment 7, six doses of glyphosate (0; 480; 960; 1,920; 3,840; 5,760 g a.a ha-1) were tested for each material. In the first study, the applications did not result on visual injuries or decrease of the other parameters, such as yield. In the experiments involving 2,4-D herbicide, there was a lower ETR at 21 and 28 DAA for the higher doses in the isoline, affecting plant height and dry mass. Haloxyfop-methyl applications did not reduce any of the variables for aad-1 transformed plants. However, reductions >50% of the ETR were observed for the isoline at 3 DAA, and hence a decrease in the ethereal extract. For the glyphosate experiment, no significant differences were observed. The EnList trait is safe for these herbicides when used the recommended labeled rates.
Descrição
Palavras-chave
aad-1, 2,4-D, haloxyfop-methyl, glyphosate, postemergence, isoline, pós-emergência, isolinha