Banca de DEFESA: GEPATRIK RODRIGUES LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : GEPATRIK RODRIGUES LIMA
DATA : 28/02/2020
HORA: 09:00
LOCAL: Sala 1 do PPGF
TÍTULO:

Physiological responses of cowpea to herbicides. 

PALAVRAS-CHAVES:

Growth analysis, development, selectivity, tolerance.

PÁGINAS: 114
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Fisiologia de Plantas Cultivadas
RESUMO:

Cowpea is one of the components of the diet of Brazilians, mainly in the North and Northeast regions. Economic losses can occur with the competition between culture and weeds, requiring management strategies, including herbicide use. However, a better understanding of herbicide impacts on the physiological responses of culture contributes to the development of more appropriate management practices. The objective of this work was to evaluate physiological responses of cowpea beans (BRS Guariba) and its tolerance to post-emerging herbicides conducted in a no-tillage and conventional system in UFRRJ (Seropédica, RJ). The experiment was in a randomized block design, with four replications, and each plot had 10 m2. The treatments consisted of herbicides applied at 21 days after sowing (DAS): fluazifop-p-butyl (187.5 g ha^-1) and mixtures of herbicides fluazifop-p-butyl + fomesafen, ranging in three doses of fomesafen (187.5 + 125 g ha^-1, 187.5 + 250 g ha^-1, and 187.5 + 375 g ha^-1) and two controls without herbicide application (manual weeding and without weeding). The plant development and growth by growth analysis were evaluated, obtaining leaf area, leaf area index (IAF), crop growth rate (TCC), and liquid assimilation rate (TAL). Leaf soluble protein content (CPSF) and maximum quantum yield of photosystem II (FV/Fm) were also evaluated before herbicide application and on subsequent days after application. The control performed by herbicides and phytotoxicity to the crop was quantified. At the time of harvest, the effects of treatments on production components were evaluated. Treatments containing fomesafen demonstrated high phytotoxicity to cowpea beans, reducing leaf area and IAF sharply in the first three weeks after application. TCC and TAL also showed a decline in the same period, resulting from the intense defoliation and reduced photosynthetic area caused by fomesafen. In general, the CPSF is impacted and reduced by this herbicide when compared to control treatment in the days following the application. It has an initial impact on chlorophyll fluorescence in the first days after application. Among the production components, the number of pods per plant and productivity is reduced more severely in treatments containing fomesafen. Fluazifop has been shown to be a selective culture, not interfering with plant growth and development. Weed interference severely reduces productivity per area.

MEMBROS DA BANCA:
Presidente - 387258 - CARLOS PIMENTEL
Externa ao Programa - 2466219 - CAMILA FERREIRA DE PINHO
Externo ao Programa - 2136627 - NIVALDO SCHULTZ
Externo à Instituição - GUSTAVO RIBEIRO XAVIER - EMBRAPA
Externo à Instituição - JERRI ÉDSON ZILLI - EMBRAPA