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.

Este trabalho teve como objetivo avaliar o efeito do osmocondicionamento, seguido ou não de secagem, em dois lotes de sementes de jiló com baixo e médio vigor. As sementes foram submetidas aos tratamentos de condicionamento osmótico com polietileno glicol (PEG) 6000 nos potenciais osmóticos de -0,6, -0,9 e -1,2 MPa, por períodos de 48 e 96 horas, com e sem secagem após os tratamentos. Para a embebição das sementes nas soluções osmóticas, estas foram colocadas sobre três folhas de papel germitest em caixas tipo gerbox umedecidas com cada solução condicionadora na proporção de 3:1. A testemunha consistiu de sementes não condicionadas. O osmocondicionamento, para ambos os lotes, proporcionou resultados superiores quanto ao vigor, pelos testes de primeira contagem, comprimento de hipocótilo e de radícula, IVG, IVE, emergência e massa seca de plântulas, quando comparados às testemunhas não condicionadas. O mesmo não foi verificado para a germinação, pois praticamente não foram observadas diferenças em relação à testemunha dos lotes. Para o lote 2, as melhorias quanto ao vigor não foram maiores do que aquelas obtidas no lote 1. O condicionamento osmótico das sementes de jiló com PEG 6000 e com secagem posterior proporciona aumento no vigor das sementes dos lotes de jiló da cultivar Morro Grande, em relação àquelas não condicionadas, entretanto, sem diferenças na germinação.

We evaluated the effect of the priming with polyethyleneglicol (PEG) 6000 followed or not of drying on two lots of eggplant seeds with medium and low vigor respectively. The seeds were submitted to the treatments of priming with PEG 6000 in the osmotic potentials of -0.6, -0.9 and -1.2 MPa during 48 or 96 hours of priming with and without subsequent drying. For the soaking of seeds in osmotic solutions, these were placed over three sheets of paper boxes such germitest gerbox conditioning moistened with each solution in a 3:1 ratio. The control group was represented by unprimed seeds. The priming for both lots provided higher values in relation to the vigor through the first counting of germination, seedlings and primary root length, germination and emergence rates, emergence and dry weight of seedlings when compared to the non-primed seeds. These results were not verified for germination; significant differences practically were not observed in relation to the controls. Improvements in relation to the vigour were not higher on lot 2 than those obtained on lot 1. The priming with PEG 6000 with subsequent drying increased the vigor of eggplant seeds of the cultivar Morro Grande in relation to those non-primed, however, without differences in the germination.

Traction control is a critical aspect of mobile robots that need to traverse rough terrain, avoiding excessive slip - which may cause the terrain to collapse locally and trap the robot wheels - and guaranteeing an adequate trajectory and speed control while reducing the power requirements. Traction control of all-wheel-drive robots in rough terrain was originally motivated by space exploration, such as in the case of the Mars Exploration Rovers. However, such technology is also needed in our planet, in particular in the Amazon region. This is the case of the Hybrid Environmental Robot (HER), a 4-wheel-drive mobile robot with independent suspensions, under development at CENPES/PETROBRAS. This robot is susceptible to changing terrain conditions, facing slippery soil and steep slopes. In this work, a new traction control scheme is proposed to allow HER to maintain a desired velocity while minimizing power requirements and slippage, considering motor saturation and avoiding flip-over dynamic instability. The proposed technique is based on a redundant computed torque control scheme, analytically optimized to minimize power requirements. Simulations are performed for rough terrain conditions with 2D-profile, considering the general case of different tire-terrain contact angles at each wheel. It is found that the control scheme is able to analytically predict in real time the ideal torques required by each independent wheel to maintain the desired speed, even on very rough terrain, minimizing when possible the power consumption. The method is applicable to the 3D case as long as the roll angle of the robot chassis does not vary too much compared to the robot pitch angle.

Foram estudados os aspectos biológicos das espécies Trichogramma acacioi, T. atopovirilia e T. bennetti, com o objetivo de selecionar aquela com melhor desempenho, para utilização no controle da traça-das-crucíferas, Plutella xylostella. As características biológicas avaliadas foram parasitismo, viabilidade e razão sexual. A taxa de parasitismo variou entre 1,67 e 41,33%, sendo o maior valor observado para o T. atopovirilia e, o menor, para T. acacioi. A viabilidade variou entre 6,20% para T. acacioi a 53,34% para T. atopovirilia. Não houve diferença significativa para a razão sexual, (P<0,05), que ficou acima de 0,88. T. atopovirilia foi a espécie de melhor desempenho em laboratório quando criada sobre ovos da traça-das-crucíferas.

Biological characteristics of the egg parasitoids Trichogramma acacioi, T. atopovirilia, and T. bennetti were studied to select the one with better performance on the control of the Diamondback moth, Plutella xylostella. Parasitism rate, viability, and sex ratio were studied. Parasitism rate ranged from 1.67 to 41.33%. T. atopovirilia and T. acacioi were respectively the most and less aggressive species. The viability ranged from 6.20% for T. acacioi to 53.34% for T. atopovirilia. There were no differences on sex ratio (P < 0.05) that remained above 0,88. T. atopovirilia was the species with best performance in the laboratory when rearing on the Diamondback moth eggs.

Foram estudados os aspectos biológicos das espécies Trichogramma acacioi, T. atopovirilia e T. bennetti, com o objetivo de selecionar aquela com melhor desempenho, para utilização no controle da traça-das-crucíferas, Plutella xylostella. As características biológicas avaliadas foram parasitismo, viabilidade e razão sexual. A taxa de parasitismo variou entre 1,67 e 41,33%, sendo o maior valor observado para o T. atopovirilia e, o menor, para T. acacioi. A viabilidade variou entre 6,20% para T. acacioi a 53,34% para T. atopovirilia. Não houve diferença significativa para a razão sexual, (p<0,05), que ficou acima de 0,88. T. atopovirilia foi a espécie de melhor desempenho em laboratório quando criada sobre ovos da traça-das-crucíferas.

Biological characteristics of the egg parasitoids Trichogramma acacioi, T. atopovirilia, and T. bennetti were studied to select the one with better performance on the control of the Diamondback moth, Plutella xylostella. Parasitism rate, viability, and sex ratio were studied. Parasitism rate ranged from 1.67 to 41.33%. T. atopovirilia and T. acacioi were respectively the most and less aggressive species. The viability ranged from 6.20% for T. acacioi to 53.34% for T. atopovirilia. There were no differences on sex ratio (p<0.05) that remained above 0,88. T. atopovirilia was the species with best performance in the laboratory when rearing on the Diamondback moth eggs.

Os afloramentos rochosos graníticos do sudeste brasileiro ocorrem no litoral ou no interior. Neste segundo caso, incluem-se os Campos de Altitude, como aqueles encontrados nos cumes das Serras do Mar e da Mantiqueira. A fisionomia mais freqüentemente encontrada nos platôs é composta de mosaicos de arbustos e arvoretas, inseridos em uma matriz de touceiras de gramíneas, com pteridófitas e outras ervas dispostas espaçadamente, além de extensões variáveis de afloramentos rochosos. Apesar de freqüentes na paisagem brasileira, são escassos os trabalhos de análise estrutural da vegetação sobre afloramentos rochosos. O objetivo deste trabalho foi analisar a estrutura da vegetação sobre um afloramento rochoso granítico de altitude no Parque Estadual da Serra do Brigadeiro, MG (42°20' - 42°40' S e 20°20' - 21°00' W, 1.722 m de altitude). Foram estimados os parâmetros quantitativos de freqüência e dominância (cobertura), absolutas e relativas. A análise de agrupamento utilizou o índice de similaridade do Jaccard. Trilepis lhotzchiana, Panicum sp. 1 e Vellozia variegata apresentaram as maiores freqüências relativas, dominâncias relativas e os maiores valores de importância. Essas três espécies mais Dyckia bracteata, Rhynchospora emaciata e Tibouchina cf. manicata responderam por 98,3% da dominância relativa, os restantes 1,7% ficaram distribuídos por outras 22 espécies. A distinção das parcelas dentro dos grupos, formados na análise de agrupamento foi atribuída ao grande número de espécies de baixa freqüência.

Granitic rock outcrops of the Brazilian southeast are either coastal or inland. The latter can often have high altitudes, such as in the summits of "Serra do Mar" and "Serra da Mantiqueira", where they are known as "Campos de Altitude". The landscape on these high altitude plateaux is often a mosaic of shrubs and treelets within a bunchgrass matrix, with sparse pteridophytes and other herbs, interspersed with variable extensions of rock outcrops. Despite the pervasiveness of rock outcrops in the Brazilian landscape, studies on the structural analysis of the vegetation on such formations are scarce. This study aimed to analyze the structure of the vegetation on a highland granitic rock outcrop in "Parque Estadual da Serra do Brigadeiro", state of Minas Gerais, Southeast Brazil (42°20' - 42°40' S and 20°20' - 21°00' W, 1,722 m of elevation ). Quantitative parameters of absolute and relative frequency and dominance (cover) were estimated. The group analysis used the Jaccard similarity index. Trilepis lhotzkiana, Panicum sp. 1, and Vellozia variegata presented the highest relative frequencies, relative dominances and importance values. These three species, along with Dyckia bracteata, Rhynchospora emaciate, and Tibouchina cf. manicata, represented 98.3% of the relative dominance. The remaining 1.7% referred to 22 remaining species. The distinction among quadrats within formed groups by cluster analysis was due to the great number of low frequency species.

Visando averiguar a presença de parasitóides do gênero Trichogramma, para utilização no controle biológico de pragas na cultura do feijão-vagem, foram coletadas posturas de Urbanus proteus (L.) que apresentavam ovos com características de parasitismo (ovos escuros). Os ovos foram encaminhados ao laboratório, onde se observou 44,9% de parasitismo. Constatou-se a viabilidade de 96.3%, com a média de 6,6 indivíduos por ovo e razão sexual de 0,93. Espécimes machos foram identificados, mostrando tratar-se de Trichogramma bruni Nagaraja, espécie que até então não havia sido descrita nesse hospedeiro e cultura.

Aiming to verify the presence of eggs parasitoids of the genus Trichogramma, for using in the biological control of insects pests, were collected eggs from long tailed skipper butterfly, a lepidopteran defoliator of snap beans, which presented eggs with parasitism characteristics (dark eggs). The eggs were taken to the laboratory were 44.9% of parasitism was verified. Viability was 96.3%, with an average of 6.6 individuals per egg and a sexual ratio of 0.93. Male specimens were identified as Trichogramma bruni Nagaraja. It is the first report of parasitism in this host and culture.

Este trabalho tem por objetivo estudar a ecologia da polinização da planta invasora Triumfetta semitriloba Jacq. (Tiliaceae), em Viçosa, MG, Brasil, durante a estação de floração de 1993 e 1994. Foram escolhidas duas manchas de plantas localizadas em pastos abandonados (P1 e P2) e uma mancha em clareira de mata (P3). Dez plantas, em cada mancha, foram sorteadas. Durante um dia de cada mês de floração foi contado o número de flores abertas por planta. Todos os visitantes florais foram identificados e registrado o comportamento. Foi obtida a freqüência de visitas aos ramos floridos e alguns polinizadores foram coletados para análise da carga de pólen. As flores de T. semitriloba são actinomórficas com cinco nectários em torno da base do ovário, e abrem, seqüencialmente, no período da tarde. A fenologia floral seguiu o padrão "steady-state" modificado de Gentry. O número de flores abertas foi maior em P2, mas as diferenças entre meses não foram homogêneas entre as manchas. Considerando o comportamento enquanto coletavam pólen ou néctar, a freqüência de visita e a porcentagem de pólen de T. semitriloba na carga polínica (100% para todas as espécies de abelhas, exceto para Augochlorella michaelis que foi igual a 81%) as seguintes abelhas foram consideradas como principais polinizadoras: Augochloropsis cupreola, Augochlorella michaelis, Cressomiella aff. sussurans, Cressomiella sussurans, Cressomiella sp., Pseudocentron paulistana, Ceratinula sp1, Ceratinula sp2 e Ceratinula sp3, Melissodes sexcincta, Apis mellifera, Plebeia cf. nigriceps, Plebeia droryana. A distribuição de freqüência de visitas dos polinizadores não foi diferente entre manchas e não foi uniforme durante a antese. Houve uma maior atividade dos visitantes entre 15 e 17 horas.

This work aimed to study the pollination ecology of the tropical weed Triumfetta semitriloba Jacq. (Tiliaceae), in Viçosa, South-eastern Brazil, during the flowering season of 1993 and 1994. Two patches located in pasture (P1 and P2) and one patch in a forest trail (P3) were chosen and ten plants on each patch were sorted. The number of opened flowers were counted during one day, in each flowering month and patch. All observed flower visitors were identified and their behavior while visiting flowers was recorded. Frequency of visits to flowered branches was obtained and some pollinator individuals were captured for analysis of pollen load. Flowers are conspicuously yellow and actinomorphic, with five nectaries around the ovary base, and opened sequentially in the afternoon. Flower phenology followed a modified steady-state Gentry's pattern. The number of opened flowers was higher in P2, but differences between months were not homogeneous between patches. Considering behaviour when collecting pollen or nectar, which permitted impregnation of stigma with pollen, visiting frequency and percent of T. semitriloba pollen on pollen load (100% for all of them, except for Augochlorella michaelis which was 81%) the following species were the mainly pollinators: Augochloropsis cupreola, Augochlorella michaelis, Cressomiella aff. sussurans, Cressomiella sussurans, Cressomiella sp., Pseudocentron paulistana, Ceratinula sp1, Ceratinula sp2 and Ceratinula sp3, Melissodes sexcincta, Apis mellifera, Plebeia cf. nigriceps, Plebeia droryana. Frequency of pollinators visitation was not different between patches and not uniform during anthesis. There was a higher pollinator activity between 15:00 and 17:00 hr.