Avalia����o de herbicidas no controle de plantas daninhas na cultura da soja

Foi conduzido em Serran��polis, GO, um ensaio objetivando avaliar a efici��ncia e a seletividade de herbicidas no controle de plantas daninhas na cultura da soja (Glycine max (L.) Merril), utilizando-se os seguintes tratamentos: A) 100 g/ha de imazethapyr (��cido 2-[4,5-dihidro-4-metil-4(1-metiletil)-5-oxo-1H-imidazol-2-ilo]-5-etil-3-piridinacarboxilico) + surfactante, a 0,25% v/v; B) tratamento A e 15 dias ap��s, 230 g/ha de sethoxydim (2-1-etoximino-butil-5-2(etiltio)-propil-3-hidroxi-2-ciclohexeno-1-ona) + ��leo mineral, a 0,25% v/v; C) 230 g/ha de sethoxydim + ��leo mineral, a 0,25% v/v; D) 480 + 200 + 230 g/ha de bentazon (3-isopropil-2,1,3-benzotiadiazinona-(4)-2,2-di��xido) + fomesafen (5-)2-cloro-4-(trifluorometil-fenoxi)N-metilsulfonil-2-nitrobenzamida) + sethoxydim + ��leo mineral, 0,25% v/v; E) 150 g/ha de imazaquim (2-[4,5-dihidro-4-metil-4-(1-metiletil)-5-oxo-1H-imidazol-2-ilo]-3-quinolinacarbox��lico) pr��-e e 230 g/ha de sethoxydim + ��leo mineral, 0,25% v/v; F) 250 g/ha de fomesafen + 187 g/ha de fluazipop-p-butil (butil-(R)-2-(4-(5-trifluorometil-2-piridiloxi)-fenoxi)-propionato) + surfactante a 0,2% v/v; G) 120 g/ha de imazethapyr + surfactante a 0,2% v/v; H) testemunha capinada; I) testemunha n��o capinada. O delineamento experimental foi de blocos ao acaso, com quatro repeti����es. O capim-cust��dio (Pennisetum setosum (Swartz) L. Rich) foi eficientemente controlado por todos os tratamentos qu��micos, enquanto a falsa-serralha (Emilia sonchifolia DC.) foi somente pelo tratamento D. O capim-carrapicho (Cenchrus echinatus L.) por C, D, E e F. O jo��-de-capote (Nicandra physaloides (L.) Pers.) por D.F. e G. Ocorreram inj��rias iniciais ��s plantas de soja, nos tratamentos D, E. e F. As alturas de plantas e de inser����o da primeira vagem, al��m do rendimento de gr��os, n��o foram influenciados significativamente pelos herbicidas.

Weed control in young coffee plantations through post emergence herbicide application onto total area

This study was carried out to investigate the efficiency of several herbicides under field conditions, by post-emergence application onto the entire area, their effect on the control of weeds in young coffee plantations and commercial coffee and bean intercropping system, as well as on both crops. Seedlings of Coffea arabica cv. Red Catua�� with four to six leaf pairs were transplanted to the field and treated according to conventional agronomic practices. A bean and coffee intercropping system was established by sowing three lines of beans in the coffee inter-rows. At the time the herbicides were sprayed, the coffee plants had six to ten leaf pairs; the bean plants, three leaflets; and the weeds were at an early development stage. Fluazifop-p-butyl and clethodim were selective for coffee plants and controlled only Brachiaria plantaginea and Digitaria horizontalis efficiently. Broad-leaved weeds (Amaranthus retroflexus, Bidens pilosa, Coronopus didymus, Emilia sonchifolia, Galinsoga parviflora, Ipomoea grandifolia, Lepidium virginicum, and Raphanus raphanistrum) were controlled with high efficiency by sole applications of fomesafen, flazasulfuron, and oxyfluorfen, except B. pilosa, C. didymus, and R. raphanistrum for oxyfluorfen. Sequential applications in seven-day intervals of fomesafen + fluazifop-p-butyl, or clethodim, and two commercial mixtures of fomesafen + fluazifop-p-butyl simultaneously controlled both types of weed. Cyperus rotundus was only controlled by flazasulfuron. Except for fluazifop-p-butyl and clethodim, all herbicide treatments caused only slight injuries on younger coffee leaves. However, further plant growth was not impaired and coffee plant height and stem diameter were therefore similar in the treatments, as evaluated four months later. Fomesafen, fluazifop-p-butyl, and clethodim, at sole or sequential application, and the commercial mixtures of fomesafen + fluazifop-p-butyl were also highly selective for bean crop; thus at doses recommended for bean crop, these herbicides may be applied to control weeds in coffee and bean intercropping systems by spraying the entire area.

Herbicide selectivity in alfalfa crops

This study aimed to determine the selectivity of herbicides applied in pre- and post-emergence for alfalfa crops. Three separate experiments were carried out under greenhouse conditions. The first experiment was arranged in a completely randomized design with three replications in a 4 x 11 + 1 factorial scheme , with eleven herbicides (bentazon, chlorimuron-ethyl, fomesafen, fluazifop-p-butyl, saflufenacil, imazethapyr, clethodim, nicosulfuron, imazaquin, haloxyfop-methyl and MSMA), four doses of each herbicide (0.5 D, 0.75 D, 1.0 D and 1.25 D, where D = recommended dose), plus an untreated control. The products were applied to alfalfa plants at the stage of 4 to 5 leaf pairs. In the second experiment, the effect of pre-emergent herbicides on early alfalfa development was observed through a completely randomized design with five replications in a 3 x 4 x 2 factorial scheme, with three herbicides (hexazinone, atrazine + simazine, S-metolachlor), four doses (0.5 D, 0.75 D, 1.0 D and 1.25 D), and two types of soil texture (loamy and clay soil), plus an untreated control. The third experiment evaluated the action of atrazine, 2,550 g ha-1; clomazone - 600 g ha-1; diclosulam - 25 g ha-1; diuron+hexazinone - 936 + 264 g ha-1 and diuron+hexazinone +sulfometuron - 1,386 + 391 + 33.35 g ha-1 on alfalfa sown at different times after herbicide application. The effects of the treatments on alfalfa were evaluated according to visual phytotoxicity symptoms, plant height, and biomass of roots and shoots. Among the herbicides applied at post-emergence, imazethapyr, clethodim, haloxyfop-p-methyl and MSMA were selective for alfalfa, while among those applied at pre-emergence, none were selective, regardless of soil texture. The results of the third experiment showed that the herbicides diclosulam, hexazinone + diuron and atrazine caused less toxicity in alfalfa plants.

Potencial de herbicidas para o controle de pat��genos de solo do feij��o

Pouco se conhece sobre os efeitos de herbicidas em fungos patog��nicos habitantes do solo que infectam os feijoeiros. Foi avaliado o efeito de herbicidas no crescimento micelial de Fusarium solani f. sp. phaseoli, F. oxysporum f. sp. phaseoli, Macrophomina phaseolina, Rhizoctonia solani, Sclerotium rolfsii e Sclerotinia sclerotiorum. Esses fungos causam as doen��as de solo mais danosas do feij��o. Avaliou-se, em placas de Petri, o crescimento radial desses fungos em meio batata-dextrose-��gar com cinco concentra����es (0, 1, 10, 100 e 1.000 mg L-1) dos herbicidas imazamox, fomesafen, fluazifop-p-butyl, bentazon, glyphosate e S-metolachlor. O crescimento micelial de todos os fungos decresceu acentuadamente apenas com o S-metolachlor na concentra����o de 1.000 mg L-1. Por isso, o efeito desse herbicida tamb��m foi testado em duas concentra����es (1.000 ou 12.000 mg L-1) na germina����o de escler��dios de S. rolfsi e S. sclerotiorum (miceliog��nica) ou de S. sclerotiorum (carpog��nica). N��o houve efeito significativo de S-metolachlor na germina����o miceliog��nica de escler��dios desses dois fungos. Entretanto, o S-metolachlor retardou a germina����o carpog��nica de escler��dios de S. sclerotiorum. Os resultados sugerem que o herbicida S-metolachlor tem potencial de uso no manejo de doen��as do feij��o causadas por fungos de solo.

Seletividade de herbicidas na cultura de crambe

The low productivity of crambe can be associated with many factors, among these, the competition with weeds, which reduces the yield, harvest affects and contributes to the increase in seed moisture. Therefore, this study aimed to evaluate the tolerance of crambe plants cv. FMS Brilhante to herbicides applied in preplant incorporated (PPI), preemergence (PRE), and postemergence (POST). The study was installed in a green-house and the treatments consisted of the herbicide application in: pre-plant incorporated ofdiclosulam, flumetsulam, metribuzin, and trifluralin; preemergence applicationof atrazine, diclosulam, diuron, flumetsulam, metribuzim, S-metolachlor, sulfentrazone, and trifluralin; and postemergence application ofbentazon, carfentrazone-ethyl, clefoxydim, cletodim + fenoxaprop-p-ethyl, ethoxysulfuron, fomesafen, fluazifop-p-butyl, flumioxazin, halosulfuron, imazamox, imazapic, lactofen, nicosulfuron, oxadiazon, quinclorac, and setoxydim. Visual evaluations of phytotoxicity on crambe plants were realized after applications, the seedlings were counted and the height and plant dry matter were determined in the end of the evaluation period. In conditions where the studies were conducted, we can conclude that only the trifluralin application in PRE and the application of clefoxidim+fenoxaprop-p-ethyl, fluazifop-p-butyl, quinclorac, setoxydim and clefoxydim in POST showed selectivity and potential use for FMS Brilhante crambe cultivar.

Efeito de Herbicidas sobre a Biota de Invertebrados do Solo em ��rea de Restaura����o Florestal

RESUMO O controle qu��mico de plantas daninhas �� um m��todo eficaz utilizado em florestas plantadas e em ��reas de restaura����o florestal, favorecendo o desenvolvimento das mudas florestais e a redu����o dos custos de interven����o. Entretanto, se essa estrat��gia n��o for aplicada de maneira correta, pode-se tornar um potencial causador de impactos negativos aos organismos do solo e aos processos ecol��gicos que esses participam. Avaliou-se o efeito do uso de herbicidas na biota do solo por meio da amostragem da comunidade da fauna ed��fica e testes ecotoxicol��gicos de reprodu����o e sobreviv��ncia de Folsomia candida eEnchytraeus crypticus, em ��rea-alvo de restaura����o florestal rec��m-implantada. O delineamento experimental adotado foi de blocos casualizados com quatro tratamentos e cinco repeti����es. Os tratamentos consistiram da aplica����o dos herbicidas p��s-emergentes mesotrione (0,4 L ha-1), fluazifop-P-butyl (1,0 L ha-1) e nicosulfuron (1,5 L ha-1), aplicados em ��rea total nas parcelas, mais o controle (sem aplica����o). Na ��rea de estudo, foram realizadas duas aplica����es dos herbicidas com intervalos de seis meses, onde as parcelas foram correspondentes aos tratamentos em ambas as aplica����es. Em cada parcela, foram realizadas quatro coletas de solo, sendo a primeira (coleta 1) seis dias antes da segunda aplica����o dos herbicidas na ��rea. As demais, ap��s um (coleta 2), oito (coleta 3) e 22 dias (coleta 4) dessa mesma aplica����o. A comunidade da fauna do solo foi avaliada por meio do m��todo de funis de Berlese modificado, utilizando-se uma amostra de solo por parcela. Em laborat��rio, os indiv��duos foram contados e identificados em grandes grupos. Os ensaios ecotoxicol��gicos de sobreviv��ncia e reprodu����o de F. candida e E. crypticus foram realizados a partir de uma amostra composta de solo por tratamento. Um dia ap��s a aplica����o do herbicida mesotrione, verificou-se diminui����o da riqueza m��dia nos ��ndices Shannon Weaver e Pielou e na reprodu����o de E. crypticus. Concluiu-se que a dupla aplica����o dos herbicidas fluazifop-P-buthyl e nicosulfuron, nas respectivas doses de 1,0 e 1,5 L ha-1, n��o promoveu impactos negativos para os invertebrados do solo. Os efeitos negativos apresentados pelo mesotrione, mesmo que tempor��rios, remeteu a uma pondera����o sobre o uso desse em ��reas de restaura����o florestal.

Growth, production and quality of pineapple in response to herbicide use

In pineapple fields, weed competition is exacerbated by the fact that the crop is small and has a very slow vegetative development. The objective of this study was to determine the effects of herbicides on growth, yield and quality of pineapple, cultivar 'P��rola'. The experimental design was in randomized blocks with four treatments and four replications. Treatments consisted of weeding by hoe and the herbicides diuron; fluazifop-p-butyl and atrazine + S-metolachlor applied in post-emergence. The characteristics evaluated monthly during the vegetative stage were stem diameter, D-leaf length, number of leaves, number of emitted leaves and percentage of natural floral induction. In the reproductive phase, evaluations were made of average fruit weight (g) with and without crown, fruits length and diameter, number of slip, slip-sucker and sucker type seedlings, determination of soluble solids and pH in the pulp. There was no effect of herbicide treatment on the vegetative growth characteristics. Stem diameter increased until 330 days after planting, showing a decrease after this period. The D-leaf grew over time in all treatments, although phytotoxicity symptoms were observed after the first application of herbicides. The traits evaluated on the reproductive phase showed no significant differences in response to treatments. Therefore, the use of diuron fluazifop-p-butyl and atrazine + S-metolachlor did not affect growth, yield and fruit quality of pineapple, cultivar 'P��rola'.

Altera����o das caracter��sticas biol��gicas dos bi��tipos de azev��m (Lolium multiflorum) ocasionada pela resist��ncia ao herbicida glyphosate

A resist��ncia de bi��tipos de azev��m ao herbicida glyphosate est�� alterando o manejo da vegeta����o de cobertura do solo em pomares de ma����. O objetivo deste trabalho foi determinar a dose de glyphosate necess��ria para reduzir 50% do ac��mulo de mat��ria seca (GR50), a resposta do bi��tipo resistente e sens��vel a herbicidas graminicidas e o ac��mulo de mat��ria seca destes bi��tipos durante o ciclo. Para isso, foram conduzidos tr��s experimentos. No primeiro, os tratamentos constaram de doses crescentes de glyphosate aplicadas sobre plantas dos bi��tipos resistente e sens��vel para determinar o GR50. No segundo experimento, os tratamentos constaram de doses dos herbicidas glyphosate, haloxyfop-r, diclofop, fluazifop-p, fenoxaprop-p e paraquat. No terceiro experimento, sementes dos bi��tipos resistente e sens��vel foram semeadas em recipientes com capacidade para 10 L e as plantas originadas delas foram colhidas quinzenalmente, para determina����o da mat��ria seca da parte a��rea, radicular e total. Como resultados, foi obtido GR50 de 287,5 e de 4.833,5 g e.a. ha-1 de glyphosate para os bi��tipos sens��vel e resistente, respectivamente, e verificou-se que existem diferen��as significativas na resposta dos bi��tipos aos herbicidas graminicidas, dependendo da dose utilizada. Al��m disso, o bi��tipo sens��vel evidenciou maior capacidade de ac��mulo de mat��ria seca e produ����o de sementes. Constatouse, assim, fator de resist��ncia (FR) de 16,8 e que o mecanismo de resist��ncia provoca altera����es nas caracter��sticas biol��gicas do bi��tipo resistente e afeta a sensibilidade deste aos herbicidas graminicidas.

Efic��cia de herbicidas inibidores da ACCase no controle de gram��neas em lavouras de soja

Objetivou-se com este trabalho avaliar a efic��cia de herbicidas inibidores da ACCase, aplicados isoladamente ou em associa����es, no controle das esp��cies de plantas daninhas pertencentes �� fam��lia das gram��neas Brachiaria decumbens, Digitaria ciliaris, Eleusine indica, Brachiaria plantaginea e Cenchrus echinatus, na cultura da soja. O experimento foi conduzido em campo, em delineamento de blocos ao acaso com quatro repeti����es. Os tratamentos avaliados foram: clethodim (84 g ha-1), clethodim + quizalofop-p-ethyl (48 + 40 g ha-1), [clethodim + fenoxaprop-p-ethyl] (50 + 50 g ha-1), sethoxydim (230 g ha-1), tepraloxydim (100 g ha-1), fluazifop-p-butyl (125 g ha-1), haloxyfop-methyl (60 g ha-1) e testemunha sem herbicida. A conviv��ncia das plantas de soja com as gram��neas infestantes resultou em perda significativa na produtividade de gr��os. Os melhores n��veis de controle de B. decumbens foram verificados com a utiliza����o de haloxyfop-methyl. Tepraloxydim pode ser considerado seletivo a B. decumbens. Nenhum tratamento proporcionou controle final de D. ciliaris superior a 90%, por��m menor efici��ncia foi verificada quando se aplicaram sethoxydim e fluazifop-p-butyl. Apenas os tratamentos sethoxydim e [clethodim + fenoxaprop-p-ethyl] n��o mostraram controle satisfat��rio de E. indica. B. plantaginea foi a esp��cie mais facilmente controlada pelos herbicidas avaliados; no entanto, haloxyfop-methyl, tepraloxydim, clethodim e [clethodim + fenoxaprop-p-ethyl] se destacaram no controle dessa invasora. A adi����o de quizalofop-p-ethyl ao clethodim proporcionou incremento significativo no controle de C. echinatus. Tamb��m os herbicidas haloxyfop-methyl e tepraloxydim apresentaram controle satisfat��rio dessa esp��cie daninha.

Efficacy of herbicides applied to Digitaria horizontalis plants under different water conditions

This project aimed to relate the control efficiency of ACCase inhibiting herbicides applied post-emergence to Digitaria horizontalis plants under different soil water contents. The experiments were conducted in a greenhouse, with the application of three different herbicides (fluazifop-p-butyl, haloxyfop-methyl, and sethoxydim + mineral oil Assist). The experimental design used for each herbicide was completely randomized, with four replications, consisting of a 3 x 4 factorial, with the combination of water management strategies (-0.03, -0.07 and -1.5 MPa) and four doses of these products (100%, 50%, 25%, and 0% of the recommended dose). Herbicide application was made at two vegetative stages, 4-6 leaves and 2-3 tillers. The visual phytotoxicity evaluations were performed at 14 days after application and the plant dry weight at the end of the study was evaluated. The control efficiency was not affected by water management strategies when applied to the recommended dose of the herbicides in early stages of plant development (4-6 leaf stage). In late applications (2-3 tiller stage) the plants held under drought stress showed less phytotoxicity.

Efici��ncia de herbicidas para a cultura do feij��o-caupi

Com o objetivo de avaliar a seletividade e efic��cia de herbicidas para a cultura do feij��o-caupi (Vigna unguiculata), conduziu-se um experimento no esquema de parcelas subdivididas, no delineamento de blocos casualizados. Nas parcelas, foram avaliados nove herbicidas/misturas (S-metolachlor, bentazon + imazamox, S-metolachlor + bentazon + imazamox, imazamox + fluazifop-p-butyl, imazethapyr + fluazifop-p-butyl, bentazon + fluazifop-p-butyl, bentazon + imazamox + fluazifop-p-butyl, lactofen + fluazifop-p-butyl e fluazifop-p-butyl) e uma testemunha sem herbicidas, e nas subparcelas foram avaliados dois tratamentos: com capinas e sem capinas, para determinar a seletividade e a efic��cia dos herbicidas, respectivamente. Os herbicidas S-metolachlor, bentazon + imazamox, S-metolachlor + bentazon + imazamox, imazamox + fluazifop-p-butyl, imazethapyr + fluazifop-p-butyl, bentazon + fluazifop-p-butyl, bentazon + imazamox + fluazifop-p-butyl e fluazifop-p-butyl foram seletivos para a cultura. A mistura lactofen + fluazifop-p-butyl causou severa intoxica����o no feij��o-caupi, com posterior recupera����o e produtividade igual ou superior �� dos demais tratamentos. As principais esp��cies de plantas infestantes foram: Cleome affinis, Trianthema portulacastrum, Amaranthus spinosus, Commelina benghalensis e Digitaria bicornis, sendo todas controladas com efici��ncia pelos herbicidas S-metolachlor aplicado em pr��-emerg��ncia + bentazon + imazamox aplicados em p��s-emerg��ncia e lactofen + fluazifop-p-butyl aplicados em p��s-emerg��ncia. Conclui-se que a efici��ncia de herbicidas para o feij��o-caupi depende da seletividade para a cultura, bem como de sua efic��cia no controle de plantas daninhas, a qual pode variar de acordo com a comunidade infestante.

Volunteer RR�� corn management in roundup ready�� soybean-corn succession system

The present study evaluated the effects of cover crops (Pennisetum glaucum, Crotalaria spectabilis and Urochloa ruziziensis) associated with the application of herbicides {glyphosate; (glyphosate + haloxyfop-R); (glyphosate + fluazifop-p-butyl); (glyphosate + imazethapyr) and (glyphosate + imazaquin)} in soybean desiccation management for volunteer RR�� corn control. The experiment was conducted under field conditions at Sinop-MT, during the 2013/2014 crop season, in a randomized complete blocks design with factorial scheme and four replications. The following parameter were evaluated: dry matter of cover crops and ground coverage rate, control of volunteer RR�� corn present at the time of desiccation, dry matter, height and intoxication level on soybean plants caused by herbicides at 7, 14 and 28 days after emergence (DAE), control of volunteer RR�� corn derived from emergence fluxes subsequent to desiccation management and soybean yield. The joint application of (glyphosate + haloxyfop-R) provided the best level of volunteer RR�� corn control present at the time of desiccation. Satisfactory control (80%) of volunteer corn was obtained with the application of (glyphosate + imazethapyr). This treatment displayed an additional residual effect of imazethapyr, which efficiently controled volunteer RR�� corn derived from fluxes subsequent to desiccation management, especially in treatments performed under U. ruziziensis straw. None of the herbicides used in desiccation management caused any significant effect on dry matter, height and phytotoxicity of soybean plants at 7, 14 and 28 DAE nor on grain yield.

The promotion of grassland forb abundance: A chemical or biological solution?

Techniques that increase the biodiversity value of species-poor grassland are required if conservation targets aimed at reversing the decline in species-rich grassland are to be met. This study investigated the diversification of swards dominated by Lolium perenne by testing the efficacies of two treatments applied to reduce competitive exclusion of species introduced as seed. The 'biological' treatment was the addition of the hemiparasitic plant species introduced as seed. The 'biological' treatment was the application of a selective graminicide, fluazifop-P-butyl (Fusilade 250EW). Changes in plant community composition were monitored for a period of 2 years. Values of plant species richness increased significantly between years regardless of treatment, but to a greater extent in plots sown with R. minor. The number of established sown species and their richness and tended to promote unsown species rather than those introduced as seed. Overall, the R. minor treatment was associated with the greatest impact on sward composition, facilitating establishment and development of the introduced species and promoting forb abundance. (c) 2007 Gessellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

New tools to boost butterfly habitat quality in existing grass buffer strips

There are approximately 29,000 ha of grass buffer strips in the UK under Agri-Environment Schemes; however, typically they are floristically poor and as such are of limited biodiversity value. Introducing a sown wildflower component has the potential to increase dramatically the value of these buffer strips for a suite of native species, including butterflies. This study investigates management practices aiming to promote the establishment and maintenance of wildflowers in existing buffer strips. The effectiveness of two methods used to increase the establishment of wildflowers for the benefit of native butterfly species were tested, both individually and in combination. The management practices were: (1) the application of a selective graminicide (fluazifop-P-butyl) which reduces the dominance of competitive grasses; and (2) scarification of the soil which creates germination niches for sown wildflower seeds. A wildflower seed mix consisting of nine species was sown in conjunction with the scarification treatment. Responses of wildflowers and butterflies were monitored for two years after establishment. Results indicate that the combined scarification and graminicide treatment produced the greatest cover and species richness of sown wildflowers. Butterfly abundance, species richness and diversity were positively correlated with sown wildflower species richness, with the highest values in the combined scarification and graminicide treatment. These findings have confirmed the importance of both scarification as a means of introducing wildflower seed into existing buffer strips, and subsequent management using graminicides, for the benefit of butterflies. Application of this approach could provide tools to help butterfly conservation on farmland in the future.

Manejo de plantas daninhas em soja geneticamente modificada tolerante ao glyphosate

Os sistemas de produ����o transg��nicos, assim como os convencionais, exigem, al��m do controle qu��mico, a ado����o de outras estrat��gias de manejo de plantas daninhas. Objetivou-se, com este trabalho, avaliar o controle qu��mico de plantas daninhas, em soja geneticamente modificada (transg��nica) tolerante ao herbicida glyphosate associado a coberturas vegetais, na entressafra. O experimento foi instalado em ��rea experimental da FCAV/Unesp, Jaboticabal (SP). O delineamento experimental foi o de blocos ao acaso, em esquema de parcelas subdivididas, com quatro repeti����es. Nas parcelas, foram avaliadas as coberturas vegetais de Brachiaria brizantha (braquiar��o cv. Marandu), Pennisetum americanum (milheto forrageiro cv. BN2) e vegeta����o espont��nea, e, nas subparcelas, os herbicidas glyphosate, chlorimuron - ethyl + lactofen em mistura e fluazifop-p-butyl em aplica����o sequencial, al��m de duas testemunhas sem aplica����o. A cobertura com braquiar��o contribuiu para o controle qu��mico, exercendo supress��o das plantas daninhas. A aplica����o ��nica de 720 g e.a. ha-1de glyphosate, independentemente da cobertura vegetal utilizada na entressafra, foi suficiente para o controle adequado de Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp. e Eleusine indica, com resultados similares ao tratamento (chlorimuron-ethyl + lactofen) + fluazifop-p-buthyl. Comparados �� testemunha capinada, os herbicidas testados n��o afetaram a altura das plantas, massa seca da parte a��rea, massa de 100 gr��os e a produtividade de gr��os. As plantas de soja crescidas sobre os res��duos vegetais de braquiar��o e milheto forrageiro apresentaram maior altura, por��m, nenhuma outra caracter��stica avaliada na cultura foi influenciada pelas coberturas.