Tolerância de Digitaria ciliaris, Digitaria horizontalis e Digitaria nuda à herbicidas usados em cana-de-açúcar
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Data
2012-06-29
Autores
Tropaldi, Leandro [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O setor sucroalcooleiro atualmente enfrenta dificuldades no manejo de plantas daninhas em áreas com ocorrência de capim-colchão, principalmente devido à predominância de Digitaria nuda, considerada tolerante a alguns herbicidas usados em cana-de-açúcar. Dessa forma o trabalho teve como objetivo verificar a eficácia de herbicidas inibidores do fotossistema II (FSII) e da síntese de carotenóides em três espécies de capim-colchão (D. ciliaris, D. horizontalis e D. nuda). Assim, três ensaios foram conduzidos. No primeiro ensaio estudou-se a eficácia de herbicidas inibidores do FSII em dosagem única (em g i.a ha-1) em pré-emergência: ametrina (3000), hexazinona (300), amicarbazone (1050), diuron+hexazinona (1170+330), diuron (2400) e tebuthiuron (800) nas três espécies de capim-colchão, com avaliação do nível de controle aos 30 dias após a aplicação (DAA). O segundo envolveu a utilização dos herbicidas: ametrina, hexazinona, amicarbazone, diuron e tebuthiuron em sete dosagens (0, 12,5, 25, 50, 100, 200, 400% da dosagem utilizada no primeiro ensaio) aplicados em pós-emergência em cada uma das espécies; realizou-se o monitorado da taxa de transferência de elétrons (ETR) às 6 horas e aos 1, 2, 3, 4, 5, 6, 8, 15, 21 DAA, e aos 21 DAA, atribuiu-se notas visuais para os níveis de intoxicação e massa seca total da parte aérea. No terceiro ensaio, para cada espécie utilizou-se dosagens de 0, 12,5, 25, 50, 100, 200 e 400% da dosagem de 112,5 g i.a ha-1 de isoxaflutole e 1200 g i.a ha-1 de clomazone, e aos 30 DAA realizou-se avaliação visual de controle. O primeiro ensaio foi disposto em esquema fatorial considerando três espécies de capim-colchão e seis tratamentos, enquanto que o demais foram conduzidos de forma independente para cada espécie e herbicida. Todos os ensaios foram conduzidos em delineament...
The sugarcane sector currently is difficulties in the weed management n areas with occurrence of crabgrass, mainly due to predominance of Digitaria nuda, considered tolerant to some herbicides used in sugarcane. The study aimed to verify the efficacy of herbicides inhibitors of photosystem II (PSII) and synthesis of carotenoids in in three species of crabgrass (D. ciliaris, D. nuda and D. horizontalis). Thus, three assays were conducted. In the first assay was studied the efficacy of the PSII inhibitor herbicides in a single dosage (g ai ha-1) pre-emergence: ametryn (3000), hexazinone (300), amicarbazone (1050), diuron + hezaxinona (1170 +330), diuron (2400) and tebuthiuron (800) in three species of crabgrass, with evaluation of the control level at 30 days after application (DAA). The second assay involved the use of herbicides: ametryn, hexazinone, amicarbazone, diuron and tebuthiuron in seven doses (represented by 0, 12.5, 25, 50, 100, 200, 400% of reference dosage used in the assay above) of each herbicide applied in post-emergence for each specie individually. The effect was observed with the monitoring of ETR to 6 hours and at 1, 2, 3, 4, 5, 6, 8, 15, 21 days after application. At the end of 21 DAA were evaluated the intoxication levels, using visual grading, and also the total dry mass of shoots. In the third assay, for each specie were used increasing doses of the herbicides, represented by 0, 12.5, 25, 50, 100, 200 and 400% of dosage of 112 5 g ai ha-1 of ixoxaflutole and 1200 g ai ha-1 of clomazone, respectively. The visual control level evaluation was performed 30 DAA. The first assay was arranged in a factorial scheme using three species of crabgrass and seven different treatments while the second and third were conducted independently for each species and herbicide. All experiments were... (Complete abstract click electronic access below)
The sugarcane sector currently is difficulties in the weed management n areas with occurrence of crabgrass, mainly due to predominance of Digitaria nuda, considered tolerant to some herbicides used in sugarcane. The study aimed to verify the efficacy of herbicides inhibitors of photosystem II (PSII) and synthesis of carotenoids in in three species of crabgrass (D. ciliaris, D. nuda and D. horizontalis). Thus, three assays were conducted. In the first assay was studied the efficacy of the PSII inhibitor herbicides in a single dosage (g ai ha-1) pre-emergence: ametryn (3000), hexazinone (300), amicarbazone (1050), diuron + hezaxinona (1170 +330), diuron (2400) and tebuthiuron (800) in three species of crabgrass, with evaluation of the control level at 30 days after application (DAA). The second assay involved the use of herbicides: ametryn, hexazinone, amicarbazone, diuron and tebuthiuron in seven doses (represented by 0, 12.5, 25, 50, 100, 200, 400% of reference dosage used in the assay above) of each herbicide applied in post-emergence for each specie individually. The effect was observed with the monitoring of ETR to 6 hours and at 1, 2, 3, 4, 5, 6, 8, 15, 21 days after application. At the end of 21 DAA were evaluated the intoxication levels, using visual grading, and also the total dry mass of shoots. In the third assay, for each specie were used increasing doses of the herbicides, represented by 0, 12.5, 25, 50, 100, 200 and 400% of dosage of 112 5 g ai ha-1 of ixoxaflutole and 1200 g ai ha-1 of clomazone, respectively. The visual control level evaluation was performed 30 DAA. The first assay was arranged in a factorial scheme using three species of crabgrass and seven different treatments while the second and third were conducted independently for each species and herbicide. All experiments were... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Herbicidas, Fluorescencia, Plantas - Efeito dos herbicidas, Cana-de-açúcar, Sugar-cane, Fluorescence, Herbicide
Como citar
TROPALDI, Leandro. Tolerância de Digitaria ciliaris, Digitaria horizontalis e Digitaria nuda à herbicidas usados em cana-de-açúcar. 2012. viii, 58 f. Dissertação (Mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas de Botucatu, 2012.