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Our objectives were to study characteristics of the fruit (weight, percentage of husk/grain), to determine the concentration and accumulation of nutrients in the fruits, grain and husk, and to verify the existence of genetic diversity in Coffea canephora genotypes. The experiment was conducted with 20 genotypes in a four-year-old plantation, in a randomized block design with four replications and five plants per plot. The fruits were oven-dried, depulped (husk separated from the grain) and sent to a laboratory for nutritional analysis. Macronutrients N and K were the most accumulated/exported in fruits, respectively. In addition, the different genotype control cycles influenced the accumulation of nutrients in the fruits. There was genetic diversity among the 20 C. canephora genotypes, studied for the characteristics of concentration and percentage of grain/straw nutrients in the fruit. Genotypes 2, 8 and 13 were the ones with the greatest genetic distance, consequently they are the most dissimilar when compared to the other genotypes. Genotypes 8 and 1 stand out for having a higher proportion of fruit weight in relation to grains. Therefore, they are the genotypes that need a smaller amount of fruit to produce 1000 kg of ground coffee.

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The combination of plant density, fungicide, and levels of genotype resistance to white mold (WM) has not been studied for its effect on performance of common bean with type III growth habit under WM pressure. We established four sprinkler-irrigated trials in the fall to winter season in Brazil, combining density (8, 14, 20, or 26 plants/m2), genotype (susceptible or partially resistant to WM), and fungicide to manage WM (two fluazinam applications or without fluazinam) at 0.5 m row spacing in fields infested with sclerotia. One trial was established in a warm region, aiming to obtain low WM pressure. For three trials, the linear mixed model was used. WM pressure in the trials ranged from low to high. Genotype × density × fungicide and genotype × density interactions were not significant for incidence, severity, and yield for all trials. In the three trials, severity was 29% lower at eight than at 26 plants/m2, and yield at 14 plants/m2 (3,294 kg/ha) was 14% higher than yield at eight plants/m2 (P = 0.035) where fluazinam was applied. However, without fluazinam, density did not affect yield. In conclusion, choices of plant density for type III bean cultivars do not need to take into account their resistance levels to WM in the fall to winter season. However, fungicide treatment to manage WM affects the choice of density, with 8 to 12 plants/m2 recommended if fungicide is not an option to manage WM (as in organic systems), and 10 to 14 plants/m2 recommended if fungicide applications are likely.

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A wide range of soybean cultivars is available on the market and understanding the physiological response and yield of these materials is fundamental to develop new management systems. Thus, the objective of the present study was to assess ecophysiological parameters and yield of soybean cultivars under field conditions. The experiment was carried out on a farm located in the municipality of Açailândia, Maranhão, Brazil. Three commercial cultivars were used (SC1, SC2 and SC3), and gas exchanges, SPAD index, Fv/Fm, photosynthesis index (PI), instantaneous water use efficiency (WUE) and intrinsic instantaneous of the use of water (iWUE) were assessed during the vegetative (V5) and reproductive (R5) stages. In addition, the biomass and production components were obtained. A randomized complete block design was used, with three cultivars and six replications. SC2 obtained the best mean for the photochemical variables. SC2 was more efficient at both development stages in WUE, but the maximum iWUE values were obtained in SC3. The SC2 cultivar obtained the best responses in the main variables analyzed, resulting in a higher yield.

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La creciente presión antropogénica sobre la Amazonia Oriental hace imperativo el diagnóstico de la degradación forestal y, particularmente, su efecto sobre las comunidades clave dentro de los ecosistemas ribereños, unos de los últimos bosques amazónicos remantes en el estado de Maranhão. La familia de hormigas Formicidae juega un papel fundamental en el suelo, refleja los cambios en el uso de la tierra y es un grupo abundante en los bosques estudiados. Este trabajo tuvo como objetivo determinar el efecto del gradiente sucesional en la riqueza, frecuencia y composición de esta familia. El muestreo fue realizado durante los periodos seco y lluvioso con el método TSBF. Los organismos recolectados se identificaron a nivel de morfoespecies y se crearon curvas de acumulación de especies. Fueron utilizados modelos lineales mixtos para evaluar los efectos del periodo de recolecta local y estado de sucesión en la riqueza y la frecuencia de las hormigas. Por otro lado, se utilizaron regresiones polinómicas para investigar la relación entre la riqueza y la frecuencia de los formícidos según la cobertura del dosel y la altura de la vegetación. La composición de especies fue representada a través del índice de similitud de Jaccard. En total, 1 940 individuos fueron separados en 86 morfoespecies. Se obtuvo más del 80 % de la riqueza de especies probables. La frecuencia y riqueza de hormigas aumentó significativamente siguiendo la sucesión con valores bajos en las áreas abiertas durante la estación seca. Asimismo, durante esta estación, la cobertura del dosel y la altura de la vegetación tuvieron un efecto parcial en la riqueza y frecuencia de Formicidae. Por su parte, las áreas de sucesión intermedia y avanzada presentaron una composición similar con 50 especies compartidas, seguidas de las áreas de sucesión temprana con 43 y el uso antrópico con 34. Concluimos que la eliminación de los bosques ribereños tiene un efecto considerable sobre la riqueza y frecuencia de Formicidae, con valores mínimos en áreas degradadas durante la estación seca. Por otro lado, las áreas de bosques transformadas en sistemas agrícolas sufrieron pérdidas de 41 y 56% en la riqueza y frecuencia respectivamente. Con la sucesión, se restauran la estructura y las funciones del bosque favoreciendo la recolonización de las especies de hormigas. Finalmente, estos himenópteros son un grupo clave en los programas de monitoreo para la conservación/restauración de los bosques ribereños locales.

The increasing anthropogenic pressure on Eastern Amazon makes imperative the diagnosis of forest degradation, particularly the effect on key communities within the riparian ecosystems, one of the last remaining Amazonian forests in Maranhão State. The ant family Formicidae is an abundant group in these types of forests plays a fundamental role on the soil and also reflects the land use changes. Therefore, this study aimed to determine the impact of riparian forest successional stages on the Formicidae richness, frequency, and composition. Sampling was performed during both dry and wet seasons using the TSBF method. Collected organisms were identified as morphospecies. Also, species-accumulation curves were created. Linear mixed models were used to evaluate the effects of seasonal, local, and successional stage on ant richness and frequency. Polynomial regression models were applied to investigate the relationship between ant richness and frequency with canopy cover and vegetation height. Lastly, the species composition was represented by the Jaccard similarity index. In total, we observed 1 940 individuals grouped into 86 morphospecies. We obtained more than 80 % of the probable species richness. Ant frequency and richness increased significantly, following the successional stage, with low values in the open areas, especially during the dry season. Canopy cover and vegetation height seemed to affect partially both Formicidae richness and frequency during the dry season. Intermediate and advanced successional areas presented similar composition (50) shared species, followed by the areas of early succession (43) and anthropic use (34). We concluded that the elimination of riparian forests produces a considerable effect on the richness and frequency of the Formicidae family, minimally affecting them in open areas during the dry season, but resulting in losses of 41 % in richness and 56 % in frequency in forest areas when they are transformed into agricultural systems. Nevertheless, succession restores forest structure and functions, thus favoring re-colonization of ant species. Formicidae reflects forest degradation and is a key group in monitoring programs for the conservation/restoration of local riparian forests.

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Abstract Aleurocanthus woglumi (Ashby, 1915) is an important agricultural pest that causes yield losses of 20-80% in citrus plants by removing plant nutrients while feeding and allowing the formation of sooty mold. The objective of this study was to evaluate physiological changes in citrus plants in response to A. woglumi infestation under field conditions. The experiment was conducted in a citrus orchard in Paço do Lumiar, Maranhão, Brazil. Thirty-two citrus plants were used, including eight of each of the following varieties: Tahiti lime, Tanjaroa tangerine, Nissey tangerine, and Ponkan tangerine. Four random plants with A. woglumi infestation and four plants free from this pest were selected from each variety. The physiological parameters evaluated were photochemical efficiency and gas exchange. Regarding photochemical efficiency, infested plants presented photoinhibition damage, with a performance index of 4.22. The gas exchange parameters of infested plants changed, with reductions in photosynthetic CO2 assimilation of 69.7% (Tahiti), 64% (Tanjaroa), 68.8% (Nissey) and 63.3% (Ponkan). Plants infested with A. woglumi also presented physiological changes; their photosynthetic CO2 assimilation, stomatal conductance, instantaneous transpiration, and performance indexes were affected. The infested citrus plants showed photoinhibition of photosystem II. The photosynthetic CO2 assimilation decreased approximately 70% in Tahiti lime, Tanjaroa tangerine, Nissey tangerine, and Ponkan tangerine plants infested with A. woglumi.

RESUMO

The morphoagronomic characterization of 12 genotypes of M. esculenta was performed during the 2013/2014 and 2014/2015 crop years. The 12 genotypes were planted in a randomized block design, with four replicates per genotype. Number of tuberous roots per plant, weight of tuberous roots, root yield, total plant weight, harvest index, plant height, height of first branch, number of shoots, stem diameter, number of buds, leaf dry weight and petiole length were evaluated. Genotypes "Camuquem" and "Goiás" were the most productive, and "Amarela" and "Gema de Ovo" were the most divergent. Seventy percent of genetic diversity was due to petiole length (22.86%), root yield (19.20%), weight of tuberous roots (14.89%) and number of buds (13.72%). Overall, the present results indicate a broad genetic basis for the evaluated genotypes, so that such genetic variation benefits the plant breeding for future scenarios Further studies of the evaluated genotypes should be performed under environmental limitations, using biochemical and molecular tools to identify markers for genetic improvement.

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Objetivou-se selecionar e fenotipar linhagens de milho quanto à arquitetura das raízes seminais em relação à raiz primária da planta. Foram avaliadas 20 linhagens de milho em solução nutritiva, em experimento disposto no delineamento de blocos casualizados, com três repetições. Foram realizadas medições de crescimento das raízes e dos ângulos das raízes seminais. Os pêlos radiculares foram avaliados visualmente. Os resultados mostraram que as linhagens apresentaram diferenças significativas quanto ao crescimento das raízes primárias e seminal, ângulos das raízes seminais e de pêlos radiculares, não obtendo diferença apenas para número de raízes seminais. A linhagem de milho L11 foi a que apresentou maior densidade de pêlos radiculares, ângulos e crescimento de raízes seminais. Conclui-se que as linhagens de milho L11 e L14 têm os maiores ângulos das raízes seminais; as linhagens L15 e L17 têm as maiores densidades de pêlos radiculares; a linhagem L11 sobressaiu com maior número de raízes seminais.

The objective was to select and fhenotiping corn line on the seminal roots architecture in relation to the primary root of the plant. They were appraised 20 corn lines in nutrient solution in experiment provisions of randomized block design with three replications. Were measured growth of the roots and the angles of the seminal roots. The root hairs were visually assessed. The results showed that the strains exhibited significant differences in root growth and angles seminal roots and root hairs, getting no difference only for the number of seminal roots. The corn line L11 showed the highest density of root hairs, angles and growth of seminal roots. It is concluded that corn lines L11 and L14 have the highest angles of seminal roots; lines L15 and L17 have the highest density of root hairs, the L11 excelled with the largest number of seminal roots.

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The aim of this work was to evaluate the vegetative growth rate of the coffee plants (Coffea Arabica L.) and its relation with climate variables on the Cerrado of Goiás State, Brazil, based on the seasonal growth of orthotropic and plagiotropic branches with different ages in coffee trees under irrigation, water deficit and without irrigation. The experiment was carried out in a completely randomized block design with four replications and 12 plants per plot. The experimental area was divided in three treatments: plants with drip irrigation and without irrigation and submitted to water deficit for 30 days during the dry season. The plants were with seven years old, and under growth conditions of full sun, 2 m spaced between rows and 0.90 m between plants within row. The climate variables (air temperature, precipitation and relative humidity) affected on a seasonal way the vegetative growth rate of orthotropic and the group of 1º plagiotropic branches of C arabica. All evaluated branches showed similar seasonal growth, and the 1º plagiotropic branches showed different growth rates in the same period of the year. Growth rate of C arabica branches were reduced by minimal air temperature bellow 17 ºC and water deficit. Thirty days of water deficit did not affect significantly the growth of C. arabica branches; however, in non-irrigated plants significant differences on the branches

Objetivou-se avaliar a taxa de crescimento vegetativo de plantas de Coffea arabica sob diferentes regimes hídricos, bem como relacioná-la com os fatores climáticos, tendo como base o crescimento sazonal de grupos de ramos ortotrópicos e plagiotrópicos de diferentes idades, na região do Cerrado Goiano. O experimento foi instalado em delineamento de blocos casualizados, com quatro repetições e 12 plantas por parcela. A área de estudo foi dividida em três tratamentos: plantas irrigadas por gotejamento, plantas com deficiência hídrica por 30 dias na época seca e plantas não irrigadas o ano todo. Foram utilizadas plantas com sete anos de idade, cultivadas a pleno sol, no espaçamento de 2 m entre fileiras e 0,9 m entre plantas. As condições climáticas (temperatura do ar, precipitação e umidade relativa do ar) influenciaram a taxa de crescimento dos ramos ortotrópicos e plagiotrópicos da espécie C. arabica. Todos os ramos avaliados apresentaram crescimento sazonal semelhante, de modo que os ramos plagiotrópicos apresentaram taxas de crescimento diferenciada no mesmo período do ano. Sob temperaturas mínimas do ar abaixo de 17 ºC e deficiência hídrica, a taxa de crescimento dos ramos de C. arabica foi reduzida. Deficiência hídrica de 30 dias não prejudicou de forma significativa o crescimento de ramos no cafeeiro arábica; contudo, em plantas não irrigadas observou-se redução do crescime

RESUMO

The aim of this work was to evaluate the vegetative growth rate of the coffee plants (Coffea Arabica L.) and its relation with climate variables on the Cerrado of Goiás State, Brazil, based on the seasonal growth of orthotropic and plagiotropic branches with different ages in coffee trees under irrigation, water deficit and without irrigation. The experiment was carried out in a completely randomized block design with four replications and 12 plants per plot. The experimental area was divided in three treatments: plants with drip irrigation and without irrigation and submitted to water deficit for 30 days during the dry season. The plants were with seven years old, and under growth conditions of full sun, 2 m spaced between rows and 0.90 m between plants within row. The climate variables (air temperature, precipitation and relative humidity) affected on a seasonal way the vegetative growth rate of orthotropic and the group of 1º plagiotropic branches of C arabica. All evaluated branches showed similar seasonal growth, and the 1º plagiotropic branches showed different growth rates in the same period of the year. Growth rate of C arabica branches were reduced by minimal air temperature bellow 17 ºC and water deficit. Thirty days of water deficit did not affect significantly the growth of C. arabica branches; however, in non-irrigated plants significant differences on the branches

Objetivou-se avaliar a taxa de crescimento vegetativo de plantas de Coffea arabica sob diferentes regimes hídricos, bem como relacioná-la com os fatores climáticos, tendo como base o crescimento sazonal de grupos de ramos ortotrópicos e plagiotrópicos de diferentes idades, na região do Cerrado Goiano. O experimento foi instalado em delineamento de blocos casualizados, com quatro repetições e 12 plantas por parcela. A área de estudo foi dividida em três tratamentos: plantas irrigadas por gotejamento, plantas com deficiência hídrica por 30 dias na época seca e plantas não irrigadas o ano todo. Foram utilizadas plantas com sete anos de idade, cultivadas a pleno sol, no espaçamento de 2 m entre fileiras e 0,9 m entre plantas. As condições climáticas (temperatura do ar, precipitação e umidade relativa do ar) influenciaram a taxa de crescimento dos ramos ortotrópicos e plagiotrópicos da espécie C. arabica. Todos os ramos avaliados apresentaram crescimento sazonal semelhante, de modo que os ramos plagiotrópicos apresentaram taxas de crescimento diferenciada no mesmo período do ano. Sob temperaturas mínimas do ar abaixo de 17 ºC e deficiência hídrica, a taxa de crescimento dos ramos de C. arabica foi reduzida. Deficiência hídrica de 30 dias não prejudicou de forma significativa o crescimento de ramos no cafeeiro arábica; contudo, em plantas não irrigadas observou-se redução do crescime

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Objetivou-se com este trabalho quantificar a extração de nutrientes e a produção de biomassa de aveia-preta em solos submetidos a dezoito anos de adubações orgânicas e minerais em cultivo de milho. O experimento foi conduzido no Campo Experimental de Coimbra, localizado no município de Coimbra/MG, pertencente ao Departamento de Fitotecnia (DFT) da Universidade Federal de Viçosa (UFV). A semeadura da aveia-preta foi realizada no ano agrícola de 2003/2004. Os tratamentos foram: sem adubação; adubação mineral na dose de 150 kg ha-1 da fórmula 8-28-16 com a adição de 50 kg ha-1 de N em cobertura (AM1); adubação mineral na dose de 300 kg ha-1 da fórmula 8-28-16 com a adição de 100 kg ha-1 de N em cobertura (AM2) e adubação orgânica (AO) com 40 m3 ha-1 de composto orgânico. Esses tratamentos foram aplicado sequencialmente no cultivo do milho por um período de dezoito anos. Os tratamentos foram dispostos no delineamento em blocos casualizados, com quatro repetições. Foi determinado o acúmulo de massa seca da parte aérea, teor e acúmulo de N, P, K na parte aérea da aveia preta, teor de P e K no solo, saturação de base e CTC. O tratamento com adubação orgânica proporcionou maior acúmulo de massa seca da parte aérea da aveia-preta e maior extração de nutrientes. Os nutrientes determinados no solo foram diretamente proporcionais aos acúmulos de massa secas e nutrientes determinados na parte aérea da aveia-preta.

This work aimed to quantify the content and accumulation of macronutrients (N, P and K) in the dry biomass of oats-black (Avena strigosa Schreb) and in soil (P and K), recycled by the oats-black after the waste left in the soil by successive fertilizations organic and mineral carried out in maize. The experiment was conducted at the Experimental Field of Coimbra, located in the city of Coimbra / MG from the Department of Plant Science (DFT) of the Federal University of Viçosa (UFV). The planting of oats-black was conducted in the agricultural year 2003/2004. The treatments were: no fertilization, mineral fertilization at 150 kg ha-1 of 8-28-16 formulation with the addition of 50 kg ha-1 N topdressing (AM1); mineral fertilization at 300 kg ha-1 of 8-28-16 formulation with the addition of 100 kg ha-1 N topdressing (AM2) and organic manure (AO) with 40 m3 ha-1 of compost. These treatments were applied sequentially in corn cultivation for a period of eighteen. The treatments were arranged in a randomized block design with four replications. Was determined the accumulation of dry mass of aerial part, content and accumulation of N, P and K in shoots of oats-black, P and K content in soil, base saturation and CTC. The treatment with organic fertilization provided higher accumulation of dry matter of aerial part of oats-black and nutrient uptake. The nutrients determined in the soil were directly proportional to the accumulation of dry mass and specific nutrients in shoots of oats-black.

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