ABSTRACT In aquaponic systems, the residual water from the cultivation of fish is not enough to meet the nutritional demands of plants. The main objective of this study was to investigate how to adjust a nutritive solution for the cultivation of lettuce (Lactuca sativa L.) in aquaponics, based on hydroponics. The treatments included six separate crops of lettuce in an aquaponic system, while the hydroponic system served as the control. In each treatment, three blocks were used to quantify the parameters of ‘head’ diameter, number and dry weight of leaves, shoot dry weight, root dry weight, total dry weight, and the concentration and accumulation of nutrients in the total dry weight of the lettuce plants. The lower nutrient supply led to the occurrence of the lowest total dry weight in the C2 leaf crops when compared to that of the other crops of aquaponics, which had adequate time for system maturation. The system maturation and the use of a balanced solution in the C5 and C6 crops allowed the head diameter of the aquaponics plants to be equal to those of the hydroponics plants. In the aquaponic system, N and Fe were the most limiting macronutrient and micronutrient, respectively. To produce lettuce in an aquaponic system, it is necessary to ‘ripen’ the crop water for at least 30 days, and supplement micronutrients in the form of mineral fertiliser.

RESUMO No sistema de aquaponia, a água residual do cultivo dos peixes não é suficiente para suprir toda a demanda nutricional das plantas. O objetivo principal deste estudo foi investigar como ajustar uma solução nutritiva para o cultivo de alface (Lactuca sativa L.) em aquaponia, tendo como base à hidroponia. Os tratamentos foram seis culturas distintas de alface em sistemas de aquoponia e tendo como controle o sistema de hidroponia. Foram utilizados três blocos em cada tratamento para quantificar os parâmetros: diâmetro da “cabeça”, número de folhas e massa seca das folhas, massa seca da parte aérea, massa seca da raiz e massa seca total e a concentração e acúmulo de nutrientes na massa seca total de plantas de alface. O menor aporte de nutrientes, fez com que o peso seco total das folhas do cultivo C2 fossem menor quando comparadas às demais safras da aquaponia, que possuíam um adequado tempo de maturação do sistema. A maturação do sistema e o uso da solução balanceada nos cultivos C5 e C6 permitiram que o diâmetro da cabeça das plantas da aquaponia fosse igual ao da hidroponia. No sistema de aquaponia, o N foi o macronutriente mais exigido e o Fe dentre os micronutrientes. Para a produção de alface em sistema aquopônico, é necessário a maturação da água das culturas no mínimo 30 dias, juntamente com a suplementação de micronutrientes na forma de fertilizante mineral.

ABSTRACT. In Brazil, although there is a growing demand for physalis in the food industries, information on the nutritional management of the crop is still incipient. This study aimed to evaluate the biomass production and accumulation of nutrients in the shoots and fruit of physalis in two cultivation sites. Two field experiments were conducted, one where the soil was Typic Quartzipsamment in the municipality of Diamantina and the other where the soil was Rhodic Hapludox in the municipality of São João Evangelista, Minas Gerais State, Brazil. The experiments were conducted in a randomized complete block design with four replicates. The treatments were the evaluation period. Samples were collected every 15 days the day of planting of the seedlings in the field for a period of 240 days. Dry matter and nutrient accumulation in shoot and fruit were evaluated. The biomass production and nutrient accumulation were higher in the edaphoclimatic conditions at São João Evangelista compared to the conditions at Diamantina. Macronutrient accumulation was in the following order: N > K > Ca > S > Mg > P in shoot and N > K > P > S > Ca > Mg in fruit. Micronutrient accumulation in shoot and fruit was in the following order: Fe > Mn > Zn > B > Cu.

RESUMO Intoxicação por dispersão das gotas de glifosato em mudas de café são comuns, além do problema da deriva, há relatos da passagem desse herbicida para planta não alvo via rizosfera. A hidroponia possibilita comparar a translocação do glifosato absorvido pelas folhagens ou raízes e evita a interação do solo que poderia dificultar a obtenção de conclusões mais precisas quando absorvido pela raiz. Assim, a toxidade de subdoses de glifosato no crescimento inicial de plantas de café em hidroponia foi avaliada aplicando-se quatro subdoses em dois locais distintos (solução e folha). Cinquenta dias após a aplicação do herbicida, a porcentagem de intoxicação e o crescimento das mudas de café foram avaliados. A partir da subdose de 115,2 g·ha-1 de glifosato observaram-se reduções da altura; comprimento radicular; número de folhas; massa seca da folha, raiz, radicular e total; área foliar; razão de massa foliar, sendo os dois primeiros parâmetros observados somente na aplicação foliar e os demais via foliar e solução. A relação parte aérea/sistema radicular aumentaram com o incremento das subdoses do herbicida quando aplicado nas folhas e a razão de área foliar e área foliar específica aumentaram em ambas as vias de aplicação. Subdoses de glifosato aplicadas em plantas jovens de café, em condições hidropônicas, prejudicam o seu crescimento sendo mais acentuados com o aumento das doses e quando o herbicida é absorvido pelas folhas em relação à absorção radicular.

ABSTRACT Intoxication by dispersion of glyphosate droplets in coffee seedlings is common and, in addition to the problem of drift, there are reports of contamination of this herbicide to a nontarget plant via the rhizosphere. Hydroponics allows the comparison of the translocation of the glyphosate absorbed by the foliage or the roots and avoids the interaction with the soil, which could hamper the achievement of more accurate conclusions when it is absorbed by the root. Thus, the toxicity of glyphosate sublethal dosages in the initial growth of coffee plants in hydroponics was evaluated by applying four sublethal dosages in two different locations (solution and leaf). Fifty days after the application of the herbicide, the intoxication percentage and the growth of the coffee seedlings were evaluated. From the reduced dose of 115.2 g·ha-1 of glyphosate, height reductions, root length; number of leaves, dry mass of leaf, roots and total, leaf area, and leaf mass ratio were observed. The first two parameters were observed only in leaf application and the others via leaf and solution. The aerial part–root ratio system had an increase in herbicide sublethal dosages when applied to leaves and the ratio of leaf area and specific leaf area increased in both applications. Sublethal dosages of glyphosate applied to young coffee plants under hydroponic conditions impair their growth, and it is more accentuated with increasing doses and when the leaves, instead of the roots, absorb the herbicide.

Resumo: O objetivo deste trabalho foi avaliar o desempenho produtivo e os teores de nutrientes foliares em cultivares de amoreira-preta (Rubus sp.), em resposta ao aumento na adubação potássica. O experimento foi realizado em solo com pH 5,2 e 22 mg dm-3 de K, no quarto e no quinto ano de produção das cultivares Brazos, Guarani, BRS Tupy e BRS Xavante, cultivadas no estado de Minas Gerais, Brasil. As doses de K2O testadas foram distribuídas em arranjo fatorial 4x4, que consistiu em quatro doses de K2O por planta (10, 20, 30 e 40 g) e nas quatro cultivares de amoreira-preta, distribuídas em quatro delineamentos de blocos ao acaso. Foram avaliados a produtividade considerada de máxima eficiência econômica (MEE), a formação de hastes novas e o nível crítico de nutrientes foliares. A fertilização com K recomendada para o cultivo da amoreira-preta, nas condições brasileiras, não é suficiente para manter os teores de nutrientes nas folhas em nível adequado. A adubação com 20 g por planta por ano de K2O, o dobro da recomendada, favorece produtividade de MEE compatível com o desempenho produtivo das cultivares. Os teores de nutrientes foliares devem ser avaliados para recomendação da fertilização adequada para o pomar alcançar seu potencial máximo de rendimento.

Abstract: The objective of this work was to evaluate the yield performance and foliar nutrient contents of blackberry (Rubus sp.) cultivars in response to the increase in potassium fertilization. The experiment was carried out in a soil with pH 5.2 and 22 mg dm-3 K content in the fourth and fifth years of production of the Brazos, Guarani, BRS Tupy, and BRS Xavante cultivars, grown in the state of Minas Gerais, Brazil. The tested K2O rates were distributed in a 4x4 factorial arrangement, which consisted of four rates of K2O per plant (10, 20, 30, and 40 g) and of the four blackberry cultivars, distributed in four randomized complete block designs. The maximum economic efficiency (MEE) yield, the formation of primocanes, and the critical level of foliar nutrients were evaluated. The K fertilization recommended for blackberry cultivation in Brazilian conditions is not sufficient to maintain foliar nutrient contents at an adequate level. Fertilization with 20 g per plant per year of K2O, twice the recommended amount, favors the MEE yield, compatible with the yield performance of the cultivars. Foliar nutrient contents should be evaluated to recommend the proper fertilization for the orchard to reach its maximum yield potential.

RESUMO O uso de micorriza é uma biotecnologia promissora a fim de tornar a cafeicultura sustentável na utilização de adubos. Nesse sentido, foi avaliado o crescimento e teores de fósforo em cafeeiro inoculado com Rhizophagus clarus, Claroideoglomus etunicatum e Dentiscutata heterogama em solo adubado com 0; 0,74; 1,48 e 2,96 g kg-1 de P2O5. O experimento foi delineado em blocos e os tratamentos foram compostos pelo fatorial 4 x 4, com quatro repetições. As mudas micorrizadas foram previamente produzidas e posteriormente transplantadas para vasos, simulando o plantio no campo. As avaliações foram realizadas aos 150 dias após o transplantio. Todas as variáveis analisadas foram influenciadas pela inoculação, porém os efeitos foram dependentes das doses de P. Doses de P maiores que 50% da dose recomendada (0,74 g kg-1 de P2O5) diminuem o benefício da micorriza. Os fungos Rhizophagus clarus e Claroideoglomus etunicatum promovem maior crescimento das plantas de café em relação às plantas não inoculadas, nos solos não esterilizados e com redução do P aplicado.

ABSTRACT The use of mycorrhiza is a promising biotechnology that makes coffee cultivation sustainable in the use of fertilizers. In this sense, plant growth and phosphorus contents were assessed in coffee inoculated with Rhizophagus clarus, Claroideoglomus etunicatum and Dentiscutata heterogama in soil fertilized with 0, 0.74, 1.48 and 2.96 g P2O5 kg-1. The experimental design was a randomized block design in a 4 × 4 factorial scheme with four replications. The mycorrhizal seedlings were previously produced and later transplanted to pots, simulating the field planting. The assessments were performed 150 days after transplanting. All variables were influenced by inoculation, but the effects were dependent on P doses. P doses higher than 50% of the recommended dose (0.74 g P2O5 kg-1) decreased the benefit of mycorrhiza. The fungi Rhizophagus clarus and Claroideoglomus etunicatum promoted a higher growth of coffee plants when compared to non-inoculated plants in non-sterilized soils and with a reduction in the applied P.

ABSTRACT The objective of this work was to evaluate the behavior of Vetiveria zizanioides when grown in tailings from quartzite mining. A greenhouse experiment was conducted in a completely randomized experimental design with four replicates. The treatments consisted of five combinations of organic (OF) and mineral fertilization (MF) and an additional treatment of the tailings without OF or MF (control). The combinations were 0%OF/100%MF, 25%OF/75%MF, 50%OF/50%MF, 75%OF/25%MF, and 100%OF/0% MF. The doses of 100% of MF and OF were 0.025 g N, 0.025 g P2O5, 0.020 g K2O, and 5 g of corral manure per kg of quartzite tailings. V. zizanioides responded to MF at the recommended doses of 0.025 g N, 0.025 g P2O5, and 0.020 g K2O per kg of tailings. It is concluded that quartzite tailings form a favorable habitat for V. zizanioides growth, mainly after being altered by MF.

RESUMO Conduziu-se um experimento em casa de vegetação com o objetivo de avaliar o comportamento de Solanum lycocarpum sob a influência da adubação mineral e orgânica quando cultivada em rejeito da mineração de quartzito visando subsidiar ações voltadas para a recuperação de áreas de exploração de quartzito. Os tratamentos consistiram de cinco combinações de adubação orgânica (AO) e mineral (AM) e um tratamento adicional do rejeito sem AO e AM (Controle). As combinações foram: 0%AO/100%AM; 25%AO/75%AM; 50%AO/50%AM; 75%AO/25%AM; 100%AO/0% AM. As doses que corresponderam ao tratamento de 100% de AM e AO foram de 150 mg de N, 140 mg de P, 150 mg de K e 5 g de esterco de curral por dm3 de rejeito. A Solanum lycocarpum respondeu à adubação mineral e orgânica com as doses recomendadas de 36,0 mg N, 33,6 mg P e 36,0 mg K e 3,8 g de esterco de curral por dm3 de rejeito da mineração de quartzito. O acúmulo de nutrientes na espécie Solanum lycocarpum nas doses recomendadas foi na seguinte ordem na parte aérea: N> K > Ca > P > S > Mg > Mn > B > Fe > Cu > Zn com adubação mineral e orgânica para o máximo crescimento da espécie.

ABSTRACT In order to evaluate the behavior of Solanum lycocarpum, grown in sterile tailings, from mining of quartzite under the influence of mineral and organic fertilization to support actions for the recovery of exploration areas of quartzite, it was conducted an experiment in a greenhouse in a completely randomized design with four replications The treatments consisted of five combinations of mineral (MF) and organic (OF) fertilizer and an additional treatment of the sterile reject without MF and OF (Witness). The combinations were: 0%OF/100%MF; 25%OF/75%MF; 50%OF/50%MF; 75%OF/25%MF; 100%OF/0% MF. Doses of 100% MF and OF were de 150 mg de N, 140 mg de P, 150 mg de K, e 5 g bovine manure per dm3 of sterile. The Solanum lycocarpum responded to mineral fertilization with the recommended doses of 36 mg N, 33,6 mg P e 36 mg K e 3,8 g bovine manure per dm3 of sterile tailings from mining of quartzite. The accumulation of nutrients in the species Solanum lycocarpum at recommended doses in the following order was on the shoot: N> K > Ca > P > S > Mg >Mn> B > Fe > Cu > Zn with fertilization mineral and organic for maximum growth of the of species.

RESUMO Conhecer o tempo ótimo de enraizamento de miniestacas reduz o potencial de doenças e otimiza a utilização da casa de vegetação e de sombra. O objetivo do presente trabalho foi determinar o período de enraizamento das miniestacas de clone híbrido de Eucalyptus urophylla S.T. Blake e Eucalyptus grandis W. Hill ex Maiden na casa de vegetação e de sombra provenientes de minicepas submetidas a diferentes lâminas de irrigação aplicadas em minijardim e com e sem redução foliar da miniestaca. O experimento foi conduzido no viveiro da Empresa Sada Bio-Energia e Agricultura Ltda., Sete Lagoas-MG. O experimento foi instalado em delineamento em blocos casualizados no arranjo fatorial, composto por sete lâminas de irrigação e com e sem redução foliar. Os tratamentos foram definidos de acordo com a leitura diária do tanque Classe A (T1 = 50% da ET0 - frequência única; T2 = 75% da ET0 - duas vezes ao dia; T3 = 100% da ET0 - duas vezes ao dia; T4 = 125% da ET0 - três vezes ao dia; T5 = 150% da ET0 - três vezes ao dia; T6 = 100% da ET0 - frequência única e T7- operacional da empresa - lâmina 10,66 mm dia-1, fertirrigação oito vezes ao dia, durante cinco minutos com uma vazão de 0,8 L h-1). Foram avaliadas nas idades de 10, 20, 30, 40 e 50 dias, as variáveis massa seca da parte aérea, radicular e total. A lâmina de 2,19 mm dia-1 (T2) sem redução foliar apresentou menor tempo de enraizamento. O tratamento sem redução foliar proporcionou minimização do tempo de enraizamento para todas as lâminas de irrigação.

ABSTRACT Knowing the rooting optimum time reduces the potential for diseases and optimizes the use of greenhouse and shade. The aim of this study was to determine rooting period of the hybrid clone of cuttings of Eucalyptus urophylla S.T. Blake and Eucalyptus grandis W. Hill ex Maiden in the greenhouse and shade from different water irrigation level managements applied in minigardens and with two levels of foliar reduction in the minicuttings. The experiment was conducted in the nursery of the Sada Bio Energy and Agriculture Company, Sete Lagoas, Minas Gerais state, Brazil. The experiment was conducted in a randomized block design in factorial arrangement, consisting of seven irrigation management and reduced levels of two leaves (with and without reduction). The treatments were defined according to the daily reading of the Class A tank (T1 = 50% ET0 - single frequency, T2 = 75% ET0 - twice a day, T3 = 100% ET0 - twice a day, T4 = 125% ET0 - three times a day, T5 = 150% ET0 - three times a day, T6 = 100% ET0 - often single-T7 and the company operating Blade - 10.66 mm day-1, eight fertirrigation times a day for five minutes with a flow rate of 0.8 l h-1). They were assessed at ages 10, 20, 30, 40 and 50 days, the variables dry mass of minicuttings, root and total. The water irrigation level 2.19 mm / day-1 (T2) without foliar reduction showed the shortest the rooting time. The treatment without foliar reduction provided the minimizing of rooting time for all irrigation level managements (blades).

ABSTRACT The objective of this study was to evaluate the initial growth of Eremanthus incanus (Less.) Less (candeia) in soil with manganese doses. Additionally, it sought to assess manganese concentration, and accumulation in the organs of the plant as well as quantify the appropriate concentration of this element in the soil. The experiment was installed in a greenhouse and used manganese doses of 0, 50, 150 and 450 mg kg-1 soil. The experimental design used randomized blocks with five replications. Stem diameter and plant height; dry matter of root, shoot and total, and concentration and accumulation of manganese in the leaf, stem and root were evaluated. The manganese concentration in the soil was quantified using the Mehlich-1 and DTPA pH 7.3 extractors. A reduction in growth and high manganese concentrations in all parts of the plant were observed. For Melich-1 extraction the appropriate manganese concentration is 15.90 mg kg-1 and for DTPA it is 3.02 mg kg-1. The use of the candeia for phytoremediation is not recommended due to sensitivity to manganese.

RESUMO A composição química tanto quanto o acúmulo de nutrientes em caule, folhas e frutos são informações imprescindíveis para conhecer as exigências nutricionais da cultura do amendoim. Dessa forma, objetivou-se com o presente estudo avaliar a taxa de absorção de macro e micronutrientes, além de identificar as fases críticas de absorção de nutrientes na cultura do amendoim, bem como, realizar a análise de crescimento dessas plantas. Para isso foi montado um experimento em condição de campo no delineamento experimental em blocos ao acaso, com 15 tratamentos e 4 repetições. Cada tratamento correspondeu a uma época de amostragem, realizadas de 10 em 10 dias após o plantio da espécie, até o final do ciclo da cultura, que correspondeu há 160 dias. Foi observado de modo geral nas plantas de amendoim maior taxa de absorção de macro e micronutrientes aos 110 dias após a emergência, período que coincidiu com a maior taxa de crescimento da cultura. Assim, a maior taxa de absorção de nutrientes e a maior taxa de crescimento da cultura ocorreram durante o período reprodutivo, formação dos frutos e enchimento dos grãos.

ABSTRACT The chemical composition and the accumulation of nutrients in stems, leaves and fruits are essential information to meet the nutritional requirements of a peanut crop. Thus, the goals of the present study were to evaluate the rate of absorption of macro- and micronutrients; identify the critical phases of nutrient absorption in the peanut crop; and perform growth analysis of these plants. For this, an experiment under field conditions using randomized blocks with 15 treatments and four repetitions was assembled. Each treatment corresponded to a sampling time, held from 10 days after planting, until the end of the cycle, which corresponded to 160 days. Peanut plants generally showed higher macro- and micronutrient absorption rates at 110 days after emergence, coinciding with the highest growth rate of the crop. Thus, the higher nutrient absorption rate and increased crop growth rate occurred during the reproductive period, formation of fruit and grain filling.

ABSTRACT Soil pollution by heavy metals has increased worldwide and the search for plants that can be used to remediate polluted areas is an interesting alternative. The aim of this study was to evaluate the tolerance of tropical grasses to Ni and its availability for the Mehlich 1, DTPA, and USEPA 3051 and 3052 extraction methods in Ni-contaminated Oxisol. Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs ‘Aruana’ and ‘Tanzania’, Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster ‘Xaraés’ and ‘Marandu’, and Urochloa decumbens (Stapf) R.D. Webster ‘Basilisk’ were grown for 90 d in a Typic Hapludox (Oxisol) after adding 20, 40, and 120 mg Ni kg-1 to the soil. Tropical grasses showed a positive response to the application of Ni doses. The order of decreasing tolerance of tropical grasses to Ni in the soil was: ‘Basilisk’ > ‘Xaraés’ > ‘Marandu’ > ‘Aruana’ > ‘Tanzania’ based on the critical toxicity dose. Nickel concentration and accumulation increased with increasing soil Ni doses in all the tropical grasses. Mehlich 1, DTPA, USEPA 3051, and USEPA 3052 Ni extraction methods in the soil are efficient to diagnose Ni availability in tropical grasses.

ABSTRACT The aim of this study was to evaluate the effect of vegetation on soil microbial activity during spontaneous restoration and the effect of remaining eucalypts on the restoration stage of reserve ranges installed in eucalypt plantations. The studied areas were in the following stages: initial restoration stage with and without remaining eucalypts; advanced restoration stage with and without remaining eucalypts. Areas of Cerrado, native forest and commercial eucalypt plantation (Eucalypts) were evaluated for reference. Principal component analysis detected the following groups: 1- Cerrado and areas in initial restoration stage with or without eucalypts and areas in advanced restoration stage without eucalypts; 2- areas in advanced restoration stage with eucalypts; 3- native forest; 4- Eucalypts. The restoration areas are at intermediate stage of recovery, slightly superior to the advanced stage. Basal respiration, organic and microbial soil carbon and microbial and metabolic quotients were more similar to those observed in Cerrado than in eucalypt cultivation areas and little influence of the remaining eucalypts plants was observed.

RESUMO O conhecimento da quantidade de nutrientes acumulados na pitaia auxilia na recomendação de adubação equilibrada, a qual proporciona nutrição adequada e contribui para a máxima expressão do potencial dessa espécie. Objetivou-se avaliar o crescimento, acúmulo de nutrientes e eficiências de absorção, transporte e utilização de P pela pitaia, em função da adubação fosfatada. Utilizou-se o delineamento experimental em blocos casualizados, com cinco doses de P (0 mg dm-3, 20 mg dm-3, 40 mg dm-3, 80 mg dm-3 e 160 mg dm-3) incorporadas ao solo, com quatro repetições, três vasos por parcela e uma estaca por vaso. Foram observadas diferenças no acúmulo de todos os nutrientes na parte aérea e nas raízes da pitaia e nas eficiências de absorção, transporte e utilização de P, em função da adubação fosfatada. O acúmulo de nutrientes pelas raízes da pitaia obedeceu à seguinte ordem: N > K > Ca > S > P > Mg > Fe > Mn > Zn > B ≥ Cu. Na parte aérea, a ordem foi: K > N > Ca > S > Mg > P > Mn > Fe > Zn > B ≥ Cu. O crescimento inicial da pitaia foi máximo com 81 mg dm-3 de P, em Latossolo Vermelho-Amarelo distrófico. A aplicação de 44-67 mg dm-3 de P ao solo promoveu os maiores acúmulos de macro e micronutrientes na pitaia.

ABSTRACT The knowledge about the amount of nutrient uptake in pitaya plants helps the balanced fertilizer recommendation for the crop, providing adequate nutrition and contributing to the maximum expression of this species potential. This research was carried out in order to evaluate the growth, nutrient accumulation and efficiency of absorption, transportation and use of P by pitaya according to phosphorus fertilization. A randomized blocks design was used, with five doses of P (0 mg dm-3, 20 mg dm-3, 40 mg dm-3, 80 mg dm-3 and 160 mg dm-3) incorporated into the soil, with four replications, three pots per plot and one cutting per pot. Differences in the nutrient accumulation of all doses were evident in the pitaya shoots and roots, as well as in the efficiency of absorption, transport and use of P, according to phosphorus fertilization. The nutrient accumulation in the pitaya roots was ranked in the following order: N > K > Ca > S > P > Mg > Fe > Mn > Zn > B ≥ Cu. For the shoots, the order was: K > N > Ca > S > Mg > P > Mn > Fe > Zn > B ≥ Cu. The initial growth of pitaya plants was maximum with 81 mg dm-3 of P, in a Red-Yellow Dystrophic Latosol. The application of 44-67 mg dm3 of P to the soil promoted the highest accumulation of macro and micronutrients in the pitaya.

RESUMO Syngonanthus elegans é uma espécie vegetal em vias de extinção que ocorrem no Cerrado brasileiro, cuja interação com fungos micorrízicos arbusculares (FMA) é deficientemente compreendida. O objetivo deste trabalho foi avaliar a ocorrência de espécies de FMA e colonização micorrízica de S. elegans. Em duas áreas de amostragem denominadas Córrego do Soberbo (Soberbo) e Parque Nacional das Sempre-Vivas (Parque), ambas localizadas em Diamantina-MG, Brasil, uma parcela de 100 x 100 m foi estabelecida e solo da rizosfera e raízes foram coletados de 10 plantas em cada parcela. Além disso, amostragem incluiu três espécimes de cada Loudetiopsis chrysothrix e Xyris sp.. Estruturas típicas de colonização micorrízica foram observadas nas raízes de S. elegans e a colonização medida foi de 75%. Considerando as duas áreas e os três hospedeiros, 26 espécies de FMA foram recuperados, 8 delas identificadas apenas até gênero. Glomus sp. 1, Scutellospora pernambucana, Acaulospora cavernata e Acaulospora mellea foram classificados como dominantes em ambas as áreas. Além dessas, também foram consideradas dominantes Glomus sp. 4 em Soberbo, e Dentiscutata biornata e Gigaspora albida no Parque. Culturas armadilhas revelaram a presença de sete espécies adicionais. Para S. elegans, a riqueza de espécies de FMA foi ligeiramente superior no Parque do que no Soberbo. Diversidade de Simpson e equitabilidade foram ligeiramente maiores no Soberbo para as comunidades de FMA associados com S. elegans. S. elegans é altamente colonizadas por fungos micorrízicos arbusculares e associada a uma grande variedade de espécies de FMA em condições de campo, sugerindo que essa associação é importante para o estabelecimento e sobrevivência desta espécie ameaçada. Algumas espécies observadas podem ser novas para a ciência.

ABSTRACT Syngonanthus elegans is an endangered plant species occurring in the Brazilian Cerrado whose interaction with arbuscular mycorrhizal fungi (AMF) is poorly understood. The aim of this work was to evaluate the occurrence of AMF species and mycorrhizal colonization of S. elegans in two sampling areas named "Soberbo" stream (Soberbo) and "Parque Nacional das Sempre-Vivas" (Park), both found in Diamantina-MG, Brazil. In each area, one plot (100 x 100 m) was established, and roots and soil samples near the roots were collected from 10 plants in each plot. Further sampling included three specimens each of Loudetiopsis chrysothrix and Xyris sp.. Typical mycorrhizal colonization structures were observed in S. elegans roots, and colonization was measured at 75%. Considering both sites and all three hosts, 26 AMF species were recovered, 8 of which were identified only at the genus level. Glomus sp. 1, Scutellospora pernambucana, Acaulospora cavernata and Acaulospora mellea were classified as dominant in both areas. Other species were also considered dominant, including Glomus sp. 4 in Soberbo and Dentiscutata biornata and Gigaspora albida in Park. Trap cultures revealed the presence of seven additional species. For S. elegans, AMF species richness was slightly higher in Park than in Soberbo. Simpson diversity and evenness were slightly higher in Soberbo for S. elegans-associated AMF communities. Overall, S. elegans is highly colonized by arbuscular mycorrhizal fungi and is associated with a wide range of AMF species in the field, suggesting that this association is important for the establishment and survival of this threatened species. Some of the observed species may be new to science.

RESUMO: Insetos considerados pragas são fatores limitantes à expansão da eucaliptocultura no Brasil. Os pulgões da espécie Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) podem ser pragas-chave em diversas culturas, pois afetam negativamente o crescimento, o desenvolvimento e a sobrevivência das plantas. Este trabalho relata o primeiro registro de ocorrência de M. persicae em mudas de Eucalyptus urophylla conduzidas em casa de vegetação no município de Diamantina, MG, Brasil. Essa constatação sugere a implantação de um programa de manejo integrado para tal afídeo, a fim de evitar que ele se torne praga para a cultura do eucalipto.

ABSTRACT: Insect pests are limiting factors to the expansion of Eucalyptus spp. plantations in Brazil. Aphids of the species Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) are a key pests in different crops and may negatively affect the growth, development and survival of plants. This paper reports the first record of M. persicae in seedlings of Eucalyptus urophylla grown in a greenhouse in Diamantina, Minas Gerais state, Brazil. This finding suggests the implementation of an integrated management program for this aphid, in order to prevent it from becoming a pest in Eucalyptus .