Banca de DEFESA: JÉSSICA FERREIRA LOURENÇO LEAL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA FERREIRA LOURENÇO LEAL
DATA : 20/02/2018
HORA: 09:00
LOCAL: AUDITÓRIO HILTON SALLES - P1
TÍTULO:

Interaction between herbicides with different mechanisms of action for the management of Digitaria Insularis and Conyza spp in areas of soybean production

PALAVRAS-CHAVES:

sourgrass. fleabane. antagonism.

PÁGINAS: 79
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Matologia
RESUMO:

One of the major problems of agriculture is how to control weeds that are resistant to glyphosate. In Brazil the species Digitaria insularis (sourgrass) and Conyza spp. (fleabane) have been occurring together and with great aggression in soybean properties. Because they are monocotyledons and dicotyledons, the mechanism of action of the herbicide should be specific for control each species. An application of graminicides, inhibitors of the ACCase enzyme, has been the option of management of the sourgrass s resistant to glyphosate. Already for fleabane the inhibitory herbicides of ALS and the auxin-mimicking are efficient. However, people do not know much about the use of the two mechanisms of action in sequential applications or in mixtures for species control. The objective of this study was to evaluate the interaction between synergism and antagonism between ACCase inhibitors, ALS and auxin mimics for control applications of D. insularis and Conyza spp. resistant to glyphosate. The experiments were conducted in vessels with soil at the Federal University of Rio de Janeiro, Seropédica / RJ. These were developed in randomized blocks with 4 replicates, divided into 4 cases, case I and II for 3-4 field sourgrass and flowering stage, and case III and IV for construction plants in the 12-15 sheets. The herbicides used were: (A) haloxifop (62 g ha-1), (B) chloransulam (40 g ha-1) and (C) 2,4-D dimethylamine salt (670 g ha-1) sequential applications were 3, 6 and 12 days. As the applications evaluated when they are planned, there is no proposed phenological stage. Each case consisted of 10 treatments, in case I and III (control, A, C, A + C, sequential A + C and C + A with interval between applications of 3, 6 and 12 days) and the case II and IV (control A, B, A + B, sequential A + B and B + A with interval between applications of 3, 6 and 12 days). At 7 and 35 days and 14 and 35 days after application (DAA) for fleabane and sourgrass respectively, chlorophyll fluorescence and visual symptom analysis were performed and at 35 DAA the plants were collected with dry mass selection of part area and root. The data generated in the experiments were submitted to ANOVA (p <0.005), if a biometric data and visual symptom data were required and submitted to the Tuckey test and the chlorophyll fluorescence data to the Ducan test at the 5% probability level. It was possible to observe antagonism between herbicides administered without sourgrass control. The control of 100% of the plants was found in a stadium of 3-4 users of sourgrass, when haloxyfop was applied before chlorosulfan or 2,4-D in a minimum interval of 6 days. At flowering stage of sourgrass major damage was also observed with sequential haloxifop / chloransulam or 2,4-D. On the other hand, the control herbicides without control, without control of construction plants, regardless of the range or order of application of the herbicides haloxifope and cloransulam or 2,4-D, was observed 100% control. Therefore, in areas infested with fleabane and sourgrass the recommendation is to apply the graminicide 6 days before the latifolicide for an effective control of both species.

MEMBROS DA BANCA:
Presidente - 2466219 - CAMILA FERREIRA DE PINHO
Externo ao Programa - 1905333 - AROLDO FERREIRA LOPES MACHADO
Externo à Instituição - JUNIOR BORELLA - UFRRJ
Externo à Instituição - CAIO ANTONIO CARBONARI - UNESP