Taxa de crescimento, curva de dose-resposta e avaliação da metabolização de amicarbazone por biótipos de Cyperus rotundus L.
Carregando...
Arquivos
Data
2020-01-27
Autores
Dias, Marcio Furriela [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A tiririca (Cyperus rotundus) é uma planta daninha altamente problemática em todo o mundo. No Brasil infesta as mais diversas culturas e pode causar grandes prejuízos aos produtores, principalmente em culturas de crescimento inicial lento, como a cana-de-açúcar. A tiririca pode se propagar via sementes, tubérculos e rizomas, sendo importante a realização do seu controle. O amicarbazone é um herbicida, inibidor do fotossistema II, amplamente utilizado na cultura da cana-de-açúcar, para o controle de mono e dicotiledôneas, porém não há indicação para o controle de tiririca. Portanto o presente trabalho teve como objetivo caracterizar o crescimento de biótipos de C. rotundus, avaliar o desenvolvimento desses biótipos quando submetidos às doses de amicarbazone em pré-emergência e quantificar a presença dos metabólitos desamino-amicarbazone (DA) e N-Methylated des-amino (N-Me DA) sob aplicação em pós-emergência. Foram realizados três experimentos em delineamento inteiramente casualizado com cinco repetições. O primeiro experimento foi conduzido em casa de vegetação, com 9 tratamentos. Cinco tubérculos de cada biótipo foram plantados e as plantas foram avaliadas quanto ao número de plantas, massa fresca e seca da parte aérea, número de tubérculos, massa fresca e massa fresca média de tubérculos aos 90 dias após o plantio (DAP), 30 tubérculos, oriundos desse ensaio foram plantados e avaliados 30 DAP em número de plantas produzidas e brotação dos tubérculos. Para o segundo experimento foram utilizados 9 biótipos e 6 doses do herbicida amicarbazone (0; 262,5; 525; 1050; 2100; 4200 g i.a. ha-1) em pré-emergência. As plantas foram avaliadas quanto a taxa de transporte de elétrons (ETR) aos 14; 21 e 30 dias após a aplicação (DAA), número de plantas, massa fresca e seca produzidas aos 30 DAA. O terceiro experimento, contou com a avaliação dos 9 biótipos sob efeito da dose de 1050 g i.a. ha-1 de amicarbazone aplicado 30 DAP. As seguintes avaliações foram realizadas: ETR as 6, 24, 48, 72, 96, 120, 144, 168, 240, 288, 336, 408, 456, 504 e 576 horas após a aplicação (HAA); número de plantas; massa seca da parte aérea; número de tubérculos produzidos; massa fresca dos tubérculos; análise da concentração de amicarbazone (AMK), DA e N-Me DA nas partes aéreas das plantas coletadas as 168 e 576 HAA. Identificou-se que os biótipos não apresentaram um padrão único de crescimento e há efeito da quebra da dominância apical em todos os biótipos estudados. Houve redução da ETR para todos os biótipos sob efeito das doses do herbicida aplicado em pré-emergência, os biótipos sob efeito das doses AMK também apresentaram o efeito da quebra da dominância apical, no entanto as massas não diminuiram proporcionalmente ao aumento das doses do herbicida. Constatou-se a redução da ETR, os biótipos apresentaram capacidades diferenciais de absorção e metabolização do herbicida, a aplicação do amicarbazone em pós-emergência, apesar de não proporcionar controle da espécie, reduziu a quantidade de massa seca da parte aérea, número e massa fresca dos tubérculos de tiririca.
Purlple nutsedge (Cyperus rotundus) is a highly problematic weed worldwide. In Brazil it infests the most diverse crops and can cause great damage to producers, especially in slow-growing crops such as sugar cane. Purple nutsedge can propagate by seeds, tubers and rhizomes, and its control is important. Amicarbazone is a photosystem II inhibitor herbicide, widely used in sugarcane to control grasses and dicotyledons, but there is no indication to control purple nutsedge. Therefore, this study aimed to characterize different C. rotundus biotypes growth, to evaluate the development of these biotypes when subjected to diferente amicarbazone doses in the pre-emergence application and quantify the presence of desamino-amicarbazone (DA) and NMethylated des-amino (N-Me DA) metabolites in post-emergency application. Three experimentes were conducted as a completely randomized design, with five replications. The first experiment was conducted in a greenhouse with 9 treatments. Five tubers of each biotype were planted and the plants were evaluated for number of plants, fresh and dry weight aboveground, number of tubers, fresh weight and average fresh weight of tubers at 90 days after planting (DAP), 30 tubers from this trial were planted and evaluated after 30 DAP in number of plants produced and sprouting of tubers. The second experiment was implemented in a 9 x 6 design (biotypes x doses), with amicarbazone at doses of 0; 262.5; 525; 1050; 2100; 4200 g i.a. ha-1 in preemergence application. Plants were evaluated for electron transport rate (ETR) at 14; 21 and 30 days after application (DAA), number of plants, fresh and dry mass produced at 30 DAA. The third experiment was evaluated by 9 biotypes under the effect of 1050 g i.a. ha-1 of amicarbazone applied 30 DAP. The following evaluations were performed: ETR at 6, 24, 48, 72, 96, 120, 144, 168, 240, 288, 336, 408, 456, 504 and 576 hours after application (HAA); number of plants; dry mass aboveground; number of tubers; fresh mass of tubers; concentration analysis of amicarbazone (AMK), DA and N-Me DA in plants collected at 168 and 576 HAA. It was identified that the biotypes did not show a unique growth pattern and there is an effect of breaking apical dominance in all studied biotypes. ETR was reduced for all biotypes under different doses of herbicide applied in pre-emergence, biotypes under the effect of different AMK doses also had the effect of breaking apical dominance, however the masses did not decrease proportionally to the increase in doses. of the herbicide. ETR reduction was observed, the biotypes showed differential herbicide absorption and metabolization capacities, the post-emergence application of amicarbazone, did not control the species, however, it reduced dry mass aboveground, number and fresh mass from the tubers of purple nutsedge.
Purlple nutsedge (Cyperus rotundus) is a highly problematic weed worldwide. In Brazil it infests the most diverse crops and can cause great damage to producers, especially in slow-growing crops such as sugar cane. Purple nutsedge can propagate by seeds, tubers and rhizomes, and its control is important. Amicarbazone is a photosystem II inhibitor herbicide, widely used in sugarcane to control grasses and dicotyledons, but there is no indication to control purple nutsedge. Therefore, this study aimed to characterize different C. rotundus biotypes growth, to evaluate the development of these biotypes when subjected to diferente amicarbazone doses in the pre-emergence application and quantify the presence of desamino-amicarbazone (DA) and NMethylated des-amino (N-Me DA) metabolites in post-emergency application. Three experimentes were conducted as a completely randomized design, with five replications. The first experiment was conducted in a greenhouse with 9 treatments. Five tubers of each biotype were planted and the plants were evaluated for number of plants, fresh and dry weight aboveground, number of tubers, fresh weight and average fresh weight of tubers at 90 days after planting (DAP), 30 tubers from this trial were planted and evaluated after 30 DAP in number of plants produced and sprouting of tubers. The second experiment was implemented in a 9 x 6 design (biotypes x doses), with amicarbazone at doses of 0; 262.5; 525; 1050; 2100; 4200 g i.a. ha-1 in preemergence application. Plants were evaluated for electron transport rate (ETR) at 14; 21 and 30 days after application (DAA), number of plants, fresh and dry mass produced at 30 DAA. The third experiment was evaluated by 9 biotypes under the effect of 1050 g i.a. ha-1 of amicarbazone applied 30 DAP. The following evaluations were performed: ETR at 6, 24, 48, 72, 96, 120, 144, 168, 240, 288, 336, 408, 456, 504 and 576 hours after application (HAA); number of plants; dry mass aboveground; number of tubers; fresh mass of tubers; concentration analysis of amicarbazone (AMK), DA and N-Me DA in plants collected at 168 and 576 HAA. It was identified that the biotypes did not show a unique growth pattern and there is an effect of breaking apical dominance in all studied biotypes. ETR was reduced for all biotypes under different doses of herbicide applied in pre-emergence, biotypes under the effect of different AMK doses also had the effect of breaking apical dominance, however the masses did not decrease proportionally to the increase in doses. of the herbicide. ETR reduction was observed, the biotypes showed differential herbicide absorption and metabolization capacities, the post-emergence application of amicarbazone, did not control the species, however, it reduced dry mass aboveground, number and fresh mass from the tubers of purple nutsedge.
Descrição
Palavras-chave
desamino-amicarbazone, N-Methylated des-amino, Metabólitos, Herbicidas inibidores do fotossistema II, Metabolites, Photosystem II inhibitor herbicides