Respostas fisiol?gicas do feijoeiro comum a herbicidas

• Main Author: LIMA, Gepatrik Rodrigues
• Other Authors: Pimentel, Carlos
• Format: Others
• Language: Portuguese
• Published: Universidade Federal Rural do Rio de Janeiro 2017
• Subjects: Chlorophyll fluorescence; photosystem; Fluoresc?ncia da clorofila A; fotossistema; fotoinibi??o; photoinhibition; Fisiologia da Produ??o
• Online Access: https://tede.ufrrj.br/jspui/handle/jspui/1989

Submitted by Jorge Silva ([e-mail]) on 2017-08-22T19:49:00Z No. of bitstreams: 1 2016 - Gepatrik Rodrigues Lima.pdf: 1199140 bytes, checksum: a162c3135ebd07b66364dfd0d3a3b7fd (MD5) === Made available in DSpace on 2017-08-22T19:49:00Z (GMT). No. of bitstreams: 1 2016 - Gepatrik Rodrigues Lima.pdf: 1199140 bytes, checksum: a162c3135ebd07b66364dfd0d3a3b7fd (MD5) Previous issue date: 2016-02-29 === The aim of the study was to evaluate the effects of herbicides applied on post- emergence on common bean cultivation, using chlorophyll a fluorescence parameters and visual evaluation, just after theirs application. The selectivity of the herbicide in the crop was also evaluated. The experiment was conducted in the crop science experimental field at the Federal Rural University of Rio de Janeiro. The treatments were the following herbicides, bentazon (720 g ha-1), fluazifop-p-butil (187,5 g ha-1), fluazifop-p-butil + fomesafen (187,5 + 250 g ha-1), fomesafen (250 g ha-1), and two other treatments with or without weeds mechanical control, and the experimental design used was on randomized blocks, with six treatments and three replications. The bentazon was the only herbicide that induced a reduction in the maximum quantum yield of PS II (Fv/Fm), in photochemical quenching (qP) and in effective quantum yield of PS II (?FSII), while it promoted an increase in non photochemical quenching (NPQ) in the first day after its application. The Fv/Fm was the best discriminatory parameter for the evaluation of the effects of the herbicide on photosynthetic apparatus of plants in the field. All the herbicides used did not promote phytotoxicity or bean yield reduction. === O trabalho teve como objetivos avaliar os efeitos da aplica??o de herbicidas p?s-emergentes na fisiologia da cultura do feijoeiro, utilizando par?metros de fluoresc?ncia de clorofila a e a seletividade do herbicida na cultura. O experimento foi conduzido no campo experimental de Fitotecnia, da Universidade Federal Rural do Rio de Janeiro. Os tratamentos constaram das aplica??es dos seguintes herbicidas: bentazon (720 g ha-1), fluazifop-p-butil (187,5 g ha-1), fluazifop-p-butil + fomesafen (187,5 + 250 g ha-1), fomesafen (250 g ha-1) e mais duas testemunhas sem aplica??o de herbicida, sendo uma capinada e outra mantida sem capina, no delineamento casualiza??o por bloco, com quatro repeti??es. Foram avaliadas as vari?veis de fluoresc?ncia da clorofila a, conte?do de prote?na sol?vel foliar e a fitotoxicidade a cultura. O bentazon foi o ?nico que causou redu??es significativas no rendimento qu?ntico m?ximo do fotossistema II (Fv/Fm), quenching fotoqu?mico (qP), rendimento qu?ntico efetivo do fotossistema II (?FSII) e promoveu incremento no quenching n?o fotoqu?mico (NPQ) nos primeiros dias ap?s sua aplica??o. O Fv/Fm foi a vari?vel mais indicada para avaliar efeitos decorrentes da aplica??o de herbicidas no aparato fotossint?tico de plantas no campo. Todos os herbicidas testados n?o ocasionaram fitotoxicidade elevada e queda no rendimento dos gr?os do feijoeiro comum.