Na área experimental do Setor Horticultura da Escola Superior de Agricultura “Luiz de Queiroz”, foram feitos 2 ensaios em pós e pré­emergência da cultura do quiabeiro, empregando herbicidas, nas condições de solo argiloso, nos meses de dezembro de 1974 e janeiro, fevereiro, março e abril de 1975. Os herbicidas testados na pós-emergência em doses de ingrediente ativo foram: cloroxuron 3,0 kg/ha, linuron 1,5 kg/ha, diuron 2,5 kg/ha e propaclor 2,5 kg/ha. Estes produtos foram comparados em seus efeitos com duas testemunhas, uma capinada e outra não capinada. Nas avaliações da redução do número de plantas daninhas aos 30 e 70 dias, os tratamentos: testemunha capinada, diuron, cloroxuron, propaclor e linuron superaram significativamente à testemunha não capinada. No controle de Cyperus rotundos L. nenhum dos tratamentos mostrou-se eficiente. Bons contra plantas daninhas monocotiledôneas foram, o diuron até 70 dias, e o propaclor até os 30 dias. Contra dicotiledôneas o diuron foi ótimo só até os 30 dias e o cloroxuron foi regular contra monocotiledôneas e dicotiledôneas até os 70 dias. As produções do quiabo foram superiores para os tratamentos testemunha capinada e propaclor. A fitotoxicidade dos herbicidas é um fator limitante do emprego destes produtos a exceção do propaclor que foi tolerado pela cultura. Com relação aos herbicidas experimentados na pré-emergência além da trifluralina a 1 litro/ha foram os mesmos dos testados na pós-emergência. Na redução do total de plantas daninhas aos 40 e 82 dias não há diferenças significativas entre os tratamentos testemunha capinada, diuron, propaclor e cloroxuron. As monocotiledôneas foram bem controladas aos 40 dias pelos herbicidas linuron, diuron, propaclor e trifluralina e até os 82 dias só pelo diuron e a trifluralina. Contra dicotiledôneas o linuron, diuron, cloroxuron e propaclor foram bons até aos 82 dias. As produções dos tratamentos com propaclor e testemunha capinada foram as melhores. Com respeito à fitotoxicidade o propaclor foi otimamente tolerado pela cultura do quiabeiro.

Within the research area of the Horticulture Section of the College of Agriculture, University of São Paulo, two experiments were designed to study the effects of herbicides in post and pre-emergence applications in okra production. These experiments were made in clay soil during the months of December 1974 and January, February, March and April 1975. The herbicides were used in post-emergence applications at the following active rates: chloroxuron 3.0 kg/ha, linuron 1.5 kg/ha, diuron 2.5 kg/ha and propachlor 2.5 kg/ha. Two treatments, cultivated and non-cultivated, were used as controls. In the reduction of number of weeds at 30 and 70 days after treatment, the cultivated, diuron, chloroxuron, propachlor and linuron treatments were significantly better than the non-cultivated control. Cyperus rotundus L. was not controlled by any of the chemical treatments. Against narrow leaf weeds, diuron at 70 days and propachlor up to 30 days were effective in control. Against broad leaf weeds, diuron was excellent up to 30 days and chloroxuron was satisfactory against both weed types up to 70 days. Okra production was best in the cultivated and propachlor plots. Phytotoxicity is a factor limiting the use of these products with the exception of propachlor which was tolerated by the okra plants. In the pre-emergence experiments, in addition to the herbicides used in post-emergence, trifluralin was used at 1 liter/ha. There was essentially no difference in the reduction of weeds at 40 and 82 days between the cultivated, diuron, propachlor and chloroxuron treatments. All were effective. The narrow leaf weeds were well controlled after 40 days by linuron, diuron, propachlor and trifluralin and, after 82 days, by diuron and trifluralin. Against broad leaf weeds, linuron, diuron, chloroxuron and propachlor gave excellent control up to 82 days. The production of okra was the best in the treatments with propachlor and in the cultivated plots. In respect to phytotoxicity, propachlor was well tolerated by okra.