RESUMO Gramíneas forrageiras dos gêneros Urochloa e Panicum, semeadas simultaneamente à cultura do milho, podem prejudicar a produtividade de grãos da cultura, necessitando do uso de doses reduzidas de herbicida para supressão do seu crescimento e evitar possível competição das plantas com o milho. Por isso, objetivou-se avaliar o uso de doses reduzidas do herbicida mesotrione para inibição do crescimento de gramíneas forrageiras (Urochloa ruziziensis e Panium maximum, cultivares BRS Tamani e BRS Zuri) e a capacidade de recuperação destas, quando semeadas simultaneamente à cultura do milho, em sistema consorciado. Dois experimentos foram instalados em condições de safra e segunda safra, no delineamento experimental de blocos ao acaso, com quatro repetições, em esquema fatorial 3 x 4 mais 3 testemunhas de milho solteiro. As três forrageiras foram consorciadas com milho, com a semeadura simultânea, e pulverizados na pós-emergência das plantas com quatro doses de mesotrione (0, 48, 96 e 144 g ha-1) em mistura com atrazine (1,25 kg ha-1). Foram realizadas avaliações nas plantas daninhas, forrageiras e milho. Com base nos resultados obtidos, BRS Tamani foi a forrageira mais tolerante ao herbicida mesotrione, enquanto BRS Zuri, a mais sensível. O uso de mesotrione em mistura com atrazine no sistema de consórcio de milho com gramíneas forrageiras beneficiou o controle de plantas daninhas. As forrageiras testadas não interferiram na produtividade de grãos de milho, seja na condição de safra ou de segunda safra, mesmo sem a aplicação de herbicida. Panicum isso objetivouse objetivou se maximum Zuri destas consorciado acaso repetições solteiro simultânea pósemergência pós emergência 0, 0 (0 48 9 14 ha1 ha 1 ha-1 1,25 125 25 (1,2 ha1. . daninhas obtidos sensível ( ha- 1,2 12 2 (1, 1, (1

ABSTRACT Sowing forage grass species of the genera Urochloa and Panicum simultaneously with corn can hinder crop grain yield, requiring the application of low herbicide rates for suppressing their growth and preventing potential competition with corn plants. Therefore, the objective of this study was to evaluate the use of low rates of the herbicide mesotrione for inhibiting the growth of forage grass species (Urochloa ruziziensis and Panicum maximum, cultivars BRS Tamani and BRS Zuri) sown simultaneously with corn crop, as well as the recovery capacity of these grasses. Two experiments were installed, as first and second crop seasons, in a randomized experimental block design with four replications, using a 3×4 factorial arrangement and three control treatments with corn alone. Each of the three forage grasses was sown simultaneously with corn and subjected to post-emergence application of four mesotrione rates (0, 48, 96, and 144 g ha-1) with atrazine (1.25 kg ha-1). Weeds, forage grasses, and corn plants were evaluated. BRS Tamani was the most tolerant forage to mesotrione, while BRS Zuri was the most sensitive. The application of mesotrione + atrazine in the corn-forage grass intercropping system contributed to weed control. The tested forage grasses did not affect corn grain yield in the first or second crop season, even with no herbicide application. Therefore maximum installed seasons replications 34 3 4 3× alone postemergence post emergence 0, 0 (0 48 96 14 ha1 ha 1 ha-1 1.25 125 25 (1.2 ha1. . Weeds evaluated sensitive cornforage season ( 9 ha- 1.2 12 2 (1. 1. (1

Abstract Background This manuscript presents data of screening and dose-response curves of a goosegrass population from Primavera do Leste, MT, Brazil, which results in the first official report of multiple resistance of goosegrass to ACCase and EPSPs inhibiting herbicides in Brazil. Objective Evaluate the control of a goosegrass population from Primavera do Leste, MT, Brazil, suspected of resistance to the glyphosate, fenoxaprop-p-ethyl, and haloxyfop-methyl herbicides, using dose-response curves. Methods The study was carried out in two stages, the first in Brasília, DF, Brazil, and the second in Piracicaba, SP, Brazil. The first stage consisted in the initial evaluation and identification of resistance, which was confirmed in the second. In the first stage, the herbicides glyphosate, fenoxaprop-p-ethyl, and haloxyfop-methyl were applied to susceptible and resistant goosegrass populations (F1 and F2 generations) with plants with 2 and 3 tillers, using nine rates (0, 0.25, 0.5, 1, 2, 4, 8, 16, and 32 times the recommended rate). In the second stage, the herbicides were applied to susceptible and resistant populations with plants with 4 leaves, using 12 rates (0, 0.03125, 0.0625, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, and 32 times the recommended rate). Results The high sensitivity of susceptible plants combined with the high resistance level of resistant ones resulted in high resistance factors for fenoxaprop-p-ethyl and haloxyfop-methyl, with values greater than 27.8. The resistance factor for glyphosate ranged from 3.3 to 11, depending on growth stage at application time. Conclusions The goosegrass population from Primavera do Leste, MT, Brazil, presented resistance to EPSPs (glyphosate) and ACCase (haloxyfop-methyl and fenoxaprop-ethyl) inhibiting herbicides.

Abstract Glyphosate-Resistant Crops (GR crops) have caused considerable changes in weed management worldwide. In Brazil, GR cultivars of soybean and corn were officially introduced in the 2005/06 and 2011/12 crops, respectively. This technology has radically changed the weed management system, having an enormous impact on national agriculture. The objective of this review was to analyze the general aspects that led to the adoption of this technology in Brazil and present its future consequences and challenges. The adoption of GR soybean and corn was swift and comprehensive. Ten years after its introduction, GR soybean and corn are grown in most areas with these crops in Brazil. This success can be attributed to the reduction of costs, the broad spectrum of control provided by glyphosate, the solution for effective management resistance to ALS and ACCase inhibitors, the excellent managing of weeds that are difficult to control, the reduction of crop injury and carryover problems. However, the exclusive and consecutive use of glyphosate alone resulted in intense selection pressure for resistant weeds to this herbicide, which has become one of the most prominent challenges with these crops. Therefore, the future sustainability of GR soybean and corn will not be possible without the combination with other technologies, within integrated weed management.

RESUMO Os nematoides-das-galhas causam muitos prejuízos às lavouras de hortaliças no Brasil, além de possuírem grande gama de plantas hospedeiras, incluindo as plantas daninhas. Estas podem manter o inóculo ou mesmo favorecer a multiplicação desses nematoides. Diante do exposto, objetivou-se com esse trabalho avaliar a reação de espécies selecionadas de plantas daninhas, presentes em áreas cultivadas com hortaliças, aos nematoides de galhas Meloidogyne. incognita e M. enterolobii. Os experimentos foram realizados em casa de vegetação na Embrapa Hortaliças, em Brasília-DF, em delineamento inteiramente casualizado, com seis repetições. Quinze espécies de plantas daninhas foram avaliadas para reação a M. incognita raça 1, e 16 espécies de plantas daninhas foram avaliadas para a reação a M. enterolobii. Duas cultivares de tomateiro foram utilizadas como padrão de resistência e suscetibilidade. As plantas daninhas foram avaliadas quanto ao índice de galhas (IG), índice de massas de ovos (IMO), número de ovos por grama de raízes (ovos/g raízes) e fator de reprodução (FR). M. enterolobii sobrevive e se multiplica com maior facilidade nas plantas daninhas coletadas em áreas cultivadas com hortaliças do que M. incognita raça 1 e, a maioria das espécies de plantas daninhas avaliadas são hospedeiras das duas espécies de nematoides. Apenas Urena lobata (malva-roxa), Sonchus oleraceus (serralha), Euphorbia heterophylla (amendoim-bravo), Melampodium perfoliatum (estrelinha) e Tagetes sp. (cravo-de-defunto) foram imunes a M. incognita raça 1. Todas as espécies avaliadas foram hospedeiras, ou propiciaram a multiplicação de M. enterolobii. As espécies mais suscetíveis ao M. incognita raça 1 e que, portanto, necessitam de maior controle nas lavouras infestadas por esse nematoide são Ipomoea nil (corda-de-viola), I. triloba (corda-de-viola) e Eleusine indica (capim-pé-de-galinha). Para M. enterolobii as espécies mais suscetíveis são I. nil (corda-de-viola), Solanum americanum (maria-pretinha), Hyptis suaveolens (hortelã), Portulaca oleracea (beldroega), I. triloba (corda de viola) e Euphorbia heterophylla (amendoim-bravo).

ABSTRACT Root-knot nematodes cause great damage to vegetable crops in Brazil, besides having a large range of host plants, such as weeds. Weeds can maintain the inoculums or even favor the multiplication of these nematodes. In this study we evaluated the reaction of selected weed species, present in a vegetable production area, to root-knot nematodes Meloidogyne incognita and M. enterolobii. The trials were conducted in a greenhouse at Embrapa Hortaliças, Brasília-DF, in a completely randomized design with six replicates. Fifteen weed species were evaluated for M. incognita race 1, and 16 weed species were evaluated for M. enterolobii. Two tomato cultivars were evaluated as resistance and susceptibility standards. Gall index (IG), egg mass index (IMO), number of eggs per gram of roots (eggs/g roots) and reproduction factor (FR) were evaluated. M. enterolobii survives and multiplies more easily in weeds collected in vegetable production areas than M. incognita race 1 and, the great majority of weed species evaluated in this study are hosts of both nematode species. Only the species Urena lobata, Sonchus oleraceus, Euphorbia heterophylla, Melampodium perfoliatum and Tagetes sp. were immune to M. incognita race 1. All evaluated species are either hosts or favor the multiplication of M. enterolobii. The species which are the most susceptible to M. incognita race 1, and therefore require greater control of crops infected by this nematode are Ipomoea nil, I. triloba and Eleusine indica, and for M. enterolobii are I. nil, Solanum americanum, Hyptis suaveolens, Portulaca oleracea, I. triloba and Euphorbia heterophylla.