Banca de DEFESA: GLEDSON SOARES DE CARVALHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GLEDSON SOARES DE CARVALHO
DATA : 28/02/2020
HORA: 13:00
LOCAL: Sala 04 - Instituto de Agronomia
TÍTULO:

ROLE OF CYTOCHROME P450 IN ANTAGONISM THE HERBICIDES 2,4-D AND GRAMINICIDES APPLIED IN THE CONTROL OF Digitaria insularis 

PALAVRAS-CHAVES:

interaction, herbicides, metabolization, enzymes

PÁGINAS: 82
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Matologia
RESUMO:

Antagonistic interactions between herbicides can affect the control of the weeds, as occurs in the association of 2,4-D and graminicides. Little is known about this antagonistic action and there are suspicion that 2,4-D contributes to increasing of the Cytochrome P450 activity, which is an enzymatic complex acting on herbicides metabolization.  In this way, the objective of this study is investigating the Cytochrome P450 acts in the antagonism between 2,4-D and graminicides applied to control D. insularis. Two experiments were performed with replicates in green house located in the Rural University of Rio de Janeiro, using D. insularis in flowering stage. The experimental outlining was randomized blocks design in a factorial scheme 9x2+3, being the A factor, the control and the herbicides 2,4-D (1005 g ea.ha-1); clethodim (192 g ia.ha-1), (Experiment I/II-1) or haloxyfop (62,4 g i.a. ha-1), (experiment I/II-2), applied alone, in tank mixture or applied sequentially at 0, 3, 6 and 12 days intervals. The B factor with or without malathion (1000 g ha-1), which was applied two hours prior to the other treatments and the additional treatments that represent the addition of the malathion in the spray mix.  A physico-chemical compatibility test was performed to verify the behaviour of the pesticides when mixture in the tank. Fluorescence analysis were collected in 7, 14 and 35 days after applications, Visual assessments of control were performed in 7, 14, 21, 28 and 35 days and shoot dry mass after collection of the experiments at 35 days. Fluorescence analysis were collected in 7, 14 and 35 days after applications, Visual assessments of control were performed in 7, 14, 21, 28 and 35 days and shoot dry mass . The data collected were submitted to the variance test ANOVA (p ≤ 0,05), being F significant, the data were submitted to the T-test 5% probability. The results demonstrate that there was a control reduction when the 2,4-D was added with graminicides in the spray mix, however, the mixture between 2,4-D and clethodim showed a higher control in comparisson with clethodim applyed alone. It were also observed that, despite of the statistical difference between the treatments with or without inhibitor on parameters such as fluorescence, control rates and shoot dry mass, the malathion application, in general, did not show expected results, as seen in similar studies, don’t inhibiting the cytochrome P450. Besides that, the treatments that the inhibitor was added in the spray mix, provide a similar or lesser control in comparison with the treatments without the presence malathion. By the compatibility test, the mixtures with malathion do not have use restrictions and were classified as homogeneous under agitation. On the basis of these results, it is concluded that the malathion application 2 hours prior or in the mixed-tank with 2,4-D and graminicides does't have effectiveness in the control of the D. insularis. In addition to that, the herbicide clethodim, when mixtured with 2,4-D provided higher efficacy to controle the sourgrass, when it's compared with haloxyfop

MEMBROS DA BANCA:
Interna - 2466219 - CAMILA FERREIRA DE PINHO
Externo ao Programa - 1905333 - AROLDO FERREIRA LOPES MACHADO
Externa à Instituição - CRISTINA MOLL HUTHER - UFF