RESUMO: Varronia curassavica é uma espécie medicinal nativa no Brasil e sua propriedade anti-inflamatória é atribuída aos compostos α-humuleno e β-cariofileno. O objetivo foi estudar a variabilidade de população de V. curassavica. Foram coletadas folhas de 40 indivíduos de população natural, sendo estas transferidas para frascos de vidro (2 mL). Os voláteis foram extraídos e analisados por headspace estático, associado à cromatografia gasosa, acoplada à espectrometria de massas (HS-CG-EM). Detectou-se 17 compostos: monoterpenos (1,6% - 68%) e sesquiterpenos (25,7% - 79,0%), incluindo o α-humuleno e o β-cariofileno. A análise multivariada foi realizada para estimar a dissimilaridade dos indivíduos, a qual separou quatro grupos. O grupo I foi caracterizado pela presença do α-pineno, os grupos II e IV do β-cariofileno e o grupo III do β-pineno. O teor do α-humuleno apresentou pequenas variações, enquanto o do β-cariofileno contribuiu mais para a variabilidade da população. É o primeiro relato de análise da composição química de compostos voláteis de V. curassavica utilizando a técnica HS-GC-MS.

ABSTRACT: Varronia curassavica is a medicinal species native to Brazil; its anti-inflammatory properties are attributed to α-humulene and β-caryophyllene. This study to investigated the population variability of V. curassavica. Leaves were collected from 40 individuals of a natural population and transferred to glass flasks (2 mL). The volatiles were extracted and analyzed using static headspace gas chromatography coupled with mass spectrometry (HS-GC-MS). A total of 17 compounds were detected: monoterpenes (1.6% - 68%) and sesquiterpenes (25.7% - 79.0%), including α-humulene and β-caryophyllene. Multivariate analysis was performed to estimate the dissimilarity of individuals separated the compounds into four groups. Group I was characterized by the content of α-pinene, groups II and IV by β-caryophyllene, and group III by β-pinene. The abundance of α-humulene showed small variations; while β-caryophyllene showed larger variations that contributed to the population variability. This is the first report on the chemical composition analysis of volatile compounds in V. curassavica using the HS-GC-MS technique.

RESUMO: Nos últimos anos, tem aumentado o interesse crescente pelo uso de resíduos orgânicos na agricultura. Dessa forma, objetivou-se com este estudo avaliar o biochar e a casca do pequi (Caryocar brasiliense Cambess) nas propriedades químicas do solo e na produção e nutrição de plantas de feijoeiro. O experimento foi realizado em vasos com solo (4 dm3 ~ 5,44 kg), em delineamento experimental inteiramente casualizado, em esquema fatorial 4 x 3 + 2, com quatro repetições. Os tratamentos foram quatro doses de biochar (0,0, 2,5, 5,0, 7,5 e 10,0 % v/v), três tamanhos de partículas diferentes (G1, <0,5 mm; G2, 0,5-1,0 mm e G3, 1,0-2,0 mm) e dois tratamentos controle, um sem e outro com adição de corretivo da acidez do solo. O biochar de casca do pequi atuou como corretivo da acidez do solo e como fonte de potássio para as plantas. Entretanto, em doses mais elevadas de biochar, houve uma diminuição na produção das plantas de feijão devido aos desequilíbrios nutricionais.

ABSTRACT: In recent years there has been a growing interest in the use of organic waste in agriculture. In this way, was aimed with this study to evaluate the biochar from pequi shell (Caryocar brasiliense Cambess) on the soil chemical properties and on the production and nutrition of common bean plants. The experiment was carried out in pots with soil (4 dm3 ~ 5,44 kg), in a completely randomized experimental design, 4 x 3 + 2 factorial scheme, with four replications. The treatments were four doses of biochar (0.0, 2.5, 5.0, 7.5 and 10.0 % v/v), three different particle size (G1, <0.5 mm; G2, 0.5-1,0 mm and G3, 1.0-2.0 mm) and two control treatments, one without and another with addition of soil corrective acidity. The biochar from pequi shell acted as a corrective of soil acidity and as a source of potassium for the plants. However, in higher doses of biochar there was a decrease in bean plants production due to nutritional imbalances.

ABSTRACT. Leaf area is one of the most commonly used physiological parameters in plant growth analysis because it facilitates the interpretation of factors associated with yield. The different leaf formats related to soybean genotypes can influence the quality of the model fit for the estimation of leaf area. Direct leaf area measurement is difficult and inaccurate, requires expensive equipment, and is labor intensive. This study developed methodologies to estimate soybean leaf area using neural networks and considering different leaf shapes. A field experiment was carried out from February to July 2017. Data were collected from thirty-six cultivars separated into three groups according to the leaf shape. Multilayer perceptrons were developed using 300 leaves per group, of which 70% were used for training and 30% for validation. The most important morphological measures were also tested with Garson’s method. The artificial neural networks were efficient in estimating the soybean leaf area, with coefficients of determination close to 0.90. The left leaflet width and right leaflet length are sufficient to estimate the leaf area. Network 4, trained with leaves from all groups, was the most general and suitable for the prediction of soybean leaf area.

ABSTRACT: The sampling methods for soil and plant evaluation in integrated production systems need to be refined for their use in experiments. This study purposed a sampling representativeness model to evaluate soil carbon and physiological parameters of marandu palisadegrass intercropped with double rows of eucalyptus in a silvopastoral system in southeastern Brazil. Four transects were delimited within the silvopastoral system and the soil was sampled at 0-5, 5-10, and 10-20 cm depths to evaluate two parameters of soil organic matter: total organic carbon (TOC) and soil microbial carbon (Cmic). We also evaluated three physiological parameters of marandu palisadegrass: stomatal conductance, transpiration rate, and photosynthetic rate. The sampling strategy was evaluated by the Hatheway and Modified Maximum Curvature (MMC) methods. We found that cultivation of the alley with forage grass and double rows of eucalyptus must be considered to ensure sampling representativeness in a silvopastoral system, once TOC and Cmic and physiological parameters showed variation within the integrated production system. The MMC method could be useful to evaluate silvopastoral systems for experiments and characterization of agricultural areas, as 11 soil samples are representative to evaluate Cmic and TOC, and 13 samples are enough to evaluate the physiological parameters in marandu palisadegrass. The Hatheway method could be applied to experiments that need higher accuracy with a reduction in the minimum difference to be detected between the treatments and a consequent increase in the number of samples to be collected.

ABSTRACT. The aim of this study was to obtain information for the genetic improvement of kale through repeatability and phenotypic stabilization studies and to compare methodologies that represent the reliability of the estimated parameters. Thirty-three half-sib progenies were evaluated in a randomized block design with three replicates and six plants per plot. Eight harvests were evaluated in terms of the yield of fresh leaves, number of shoots, number of leaves and average mass of leaves. Then, a phenotypic repeatability and stabilization study was performed, estimating the genetic parameters σ2a, σ²g, σ²e, and the coefficient of environmental variation and repeatability using the frequentist and Bayesian methodologies. To evaluate the reliability of these estimates, intervals were obtained using the frequentist, Bayesian and bootstrap methods. It was verified that the reliable selection of progenies of half-sib of kale can be achieved in four harvests that were realized between 95 and 170 days after planting. It was observed that the frequentist and Bayesian methodologies are better suited to obtain reliable estimates of the genetic parameters evaluated, as the last one provided smaller amplitudes for the obtained intervals. The bootstrap methodologies are not recommended for phenotypic repeatability and stabilization studies in kale.

Resumo: O objetivo deste trabalho foi avaliar o efeito de doses de ácido giberélico (GA3) sobre a extensão da vida pós-colheita em banana 'Maçã' e a aplicabilidade de uso de redes neurais artificiais. Utilizou-se o delineamento inteiramente casualizado, em arranjo de parcelas subdivididas, com cinco doses de GA3, nas parcelas, e tempos de avaliação, nas subparcelas, e quatro repetições, com um buquê de três frutos por unidade amostral. Os frutos, colhidos com a casca totalmente verde, foram imersos por 10 min, à temperatura ambiente, nos seguintes tratamentos: 0 (controle), 25, 50, 75 e 100 mg L-1 de GA3. Os buquês foram armazenados em câmara de refrigeração (20±1oC, com 91% de umidade relativa do ar). As redes neurais artificiais são eficientes, proporcionando estimativas do coeficiente de determinação maiores às obtidas por modelos de regressão linear múltipla. Após 19 dias de armazenamento, a dose de 100 mg L-1 de GA3 é mais favorável à conservação pós-colheita de banana 'Maçã', em todas as características avaliadas ao longo do armazenamento.

Abstract: The objective of this work was to evaluate the effect of gibberellic acid doses on the extent of banana 'Maçã' postharvest life and the applicability of the use of artificial neural networks. A completely randomized design was carried out in a split-plot arrangement, with five doses of GA3 in the plots and evaluation times in the subplots, with four replicates, with a three-fruit bunch by sample unit. Fruit were harvested with totally green peel and were immersed for 10 min, at room temperature, in the following treatments: 0 (control), 25, 50, 75, and 100 mg L-1 GA3. The bunches were stored in a cold chamber (20±1°C, with 91% air relative humidity). Artificial neural networks are effective, providing estimates of the coefficient of determination higher than those obtained by multiple linear regression models. After 19 days of storage, the dose of 100 mg L-1 GA3 is more favorable to banana 'Maçã' postharvest conservation, in all the evaluated traits during storage.

O objetivo deste trabalho foi selecionar acessos resistentes à pinta-preta (Alternaria tomatophila) por meio da análise de agrupamento das curvas de progresso da doença em tomateiro (Solanum lycopersicum). Foram avaliados 134 acessos de tomateiro do Banco de Germoplasma de Hortaliças da Universidade Federal de Viçosa (BGH-UFV), no delineamento de blocos ao acaso, além das testemunhas suscetíveis 'Débora' e 'Santa Clara'. As plantas foram inoculadas com uma mistura de conídios de diferentes isolados de Alternaria spp. e avaliadas regularmente quanto à severidade da doença a cada três dias após a inoculação, no total de seis avaliações. Ajustou-se o modelo logístico aos dados de severidade da pinta-preta, e as estimativas obtidas para a incidência final da doença (B1) e a taxa de progresso da doença (B3) foram submetidas à análise de variância multivariada (Manova). As médias dessas estimativas, para cada acesso, foram submetidas à análise de agrupamento. Foram formados 24 grupos distintos com base no agrupamento das curvas de progresso da doença, o que possibilitou identificar os acessos BGH-2143, BGH-2235, BGH-2270 e BGH-2118 de tomateiro como potenciais fontes de resistência à pinta-preta.

The objective of this work was to select accessions resistant to early blight (Alternaria tomatophila) through cluster analysis of the disease progress curves in tomato (Solanum lycopersicum). One hundred and thirty-four tomato accessions from the Banco de Germoplasma de Hortaliças of Universidade Federal de Viçosa (BGH-UFV) were evaluated in a randomized complete block design, as well as the susceptible controls 'Débora' and 'Santa Clara'. The plants were inoculated with a mixture of spores from different Alternaria spp. isolates and evaluated regularly regarding disease severity every three days after inoculation, totalizing six evaluations. The logistic model was adjusted to data on early blight severity, and the estimates obtained for final disease incidence (B1) and rate of disease progression (B3) were subjected to multivariate analysis of variance (Manova). The means of these estimates, for each access, were subjected to cluster analysis. Twenty-four distinct groups were formed based on disease-progress curve clusters, which allowed the identification of the BGH-2143, BGH-2235, BGH-2270, and BGH-2118 accessions as potential sources of resistance to early blight.

Objetivou-se avaliar o potencial de silagens de ramas de diferentes clones de batata-doce para alimentação animal. O trabalho foi realizado na Fazenda Forquilha localizada no Distrito de Batatal, município de Diamantina MG, no período de 23/12/2007 a 23/06/2008. O experimento foi conduzido no esquema de parcelas subdivididas em delineamento de blocos completos casualizados. Foram avaliadas a produtividade de matéria verde e matéria seca das ramas e a composição químico-bromatológica, além do perfil fermentativo de suas silagens, em três idades de colheita (120, 150 e 180 dias), em oito clones de batata doce. A produtividade de matéria seca não variou com a época de colheita das ramas, obtendo-se média de 6,01t ha-1. Os teores de matéria seca nas ramas aumentaram com o ciclo da cultura, verificando-se teores médios de 11,94; 12,16 e 19,62%, aos 120, 150 e 180 dias após o corte, respectivamente. As silagens das ramas de batata-doce apresentaram altos teores protéicos e energéticos e adequado perfil fermentativo, portanto, apresentam potencial para utilização na alimentação animal, independentemente dos clones.

The objective was to evaluate the potential of silage derived from different clones of sweet potato for animal feed. The study was conducted at Forquilha Farm located in Batatal district, MG Diamantina in the period from 23/12/2007 to 23/06/2008. The experiment was conducted in split plot design in a randomized complete block. It was evaluated the green and dry matter yield, the chemical composition and the fermentative profile of silage harvested on three dates (days 120, 150 and 180), of eight clones of sweet potato. The dry matter yield did not vary according to the harvest time of the branches, resulting in an average of 6.01t ha-1. The dry matter content in the stems increased with the growth cycle, and there are average levels of 11.94, 12.16 and 19.62% on days 120, 150 and 180 after cutting, respectively. The raw potato silage showed high protein content and adequate energy fermentation and therefore, potential for use in animal feed, regardless of clones.