RESUMO: Este trabalho teve como objetivo avaliar a importância da análise de variância (ANOVA) geral preliminar na interpretação dos dados de experimentos fatoriais sob nulidade total. Para isso, avaliou-se as taxas de erro tipo I familiar (FWER acumulada) do teste F para os componentes do desdobramento da ANOVA fatorial e da ANOVA fatorial on ranks, em comparação à FWER para o efeito global de tratamentos. Além disso, avaliou-se a FWER do teste de Tukey sob nulidade total para experimentos fatoriais na presença ou ausência da proteção da ANOVA preliminar (teste F global). O estudo foi conduzido a partir da simulação de dados de 2000 experimentos, separados em quatro cenários representativos da pesquisa agrícola. Tanto para a ANOVA fatorial paramétrica, quanto para a ANOVA fatorial não-paramétrica, as FWER ultrapassaram significativamente o nível nominal de 5%, mesmo sob nulidade total. Enquanto os testes que controlam a FWER total nos fatoriais não estiverem sendo utilizados, a ANOVA fatorial não deve ser realizada sem que o teste F da ANOVA preliminar acuse um efeito significativo. O mesmo, evidentemente, não se aplica aos testes que não são de comparações múltiplas, como Bonferroni, Dunn-Sidak e outros, que não precisam proteção da ANOVA. A mesma recomendação se aplica à ANOVA fatorial on ranks.

ABSTRACT: This research evaluated the importance of a preliminary general analysis of variance (ANOVA) in the interpretation of data from factorial experiments under total nullity. For this, we evaluated the familywise type I error rate (accumulated FWER) of the F test for the unfolding of factorial ANOVA and factorial ANOVA on ranks, which were compared with the FWER for the global effect of treatments. In addition, we evaluated the FWER of the Tukey’s test under total nullity for factorial experiments in the presence or absence of preliminary ANOVA protection (omnibus F test). The study was conducted by simulating data from 2,000 experiments, which were separated into four representative agricultural research scenarios. For both the parametric factorial ANOVA and the non-parametric factorial ANOVA, the FWER significantly exceeded the nominal level of 5%, even under total nullity. While the tests that control the total FWER in the factorials are not being used, the factorial ANOVA should not be performed without the preliminary ANOVA F test showing a significant effect. This, of course, does not apply to tests that are not multiple comparisons, such as Bonferroni, Dunn-Sidak and others, which do not need ANOVA protection. The same recommendation applies to the factorial ANOVA on ranks.

ABSTRACT. Experimental statistics are a key element for innovation in the agricultural sector. Commonly used statistical methods in experimentation are relatively simple, reliable, and widely used. However, the many problems in the quality of statistical analyses reported in the agricultural science literature highlight a need for continuing discussion on and updating of this topic. This article reviews critical points about classic linear models procedures commonly used in agricultural statistics, frequent procedures in publications in the agricultural sciences. Due to the evolution of statistical science some common recommendations from the past should no longer be followed. ABSTRACT sector simple reliable However topic sciences followed

ABSTRACT One of the methods most used in obtaining undisturbed soil samples is the volumetric ring method. Undeformed samples are used, for example, in the evaluation of soil physical properties, such as soil bulk density and porosity. However, there is a diversity of volumetric rings used in the research, which makes it difficult to compare results obtained in these studies. Thus, the objective of this investigation was to compare the values of soil bulk density, microporosity and total porosity, determined from sampling with volume volumetric rings of 100 and 272 cm³, and establish the correlation between them, verifying if the comparison is valid. Soil samples were taken in 25 cultivation sites in Hapludox, which differed in the tillage, culture and/or management system, in the municipality of Rio Paranaíba, MG, at different depths. Data were submitted to Pearson correlation analysis. The correlation between the volumetric rings for all variables was significant, described by the correlation equations y=0.3788+0.7054*x (R=0.68), y=0.1342+0.6582*x (R=0.62), and y=0.1107+0.6071*x (R=0.67), for the variables density, total porosity and microporosity, respectively. It is concluded that it is possible to compare values for the variables determined from the sampling with the two volumetric rings tested.

RESUMEN Uno de los métodos más utilizados para obtener muestras de suelo inalterado es el método de anillo volumétrico. Las muestras inalteradas se utilizan, por ejemplo, en la evaluación de las propiedades físicas del suelo, como la densidad y la porosidad. Sin embargo, existe una diversidad de anillos volumétricos utilizados en investigación, lo que dificulta la comparación de los resultados obtenidos en estos estudios. Así, el objetivo de esta investigación fue comparar los valores de densidad, microporosidad y porosidad total, determinados a partir de muestreos con anillos volumétricos con un volumen de 100 y 272 cm³, y establecer la correlación entre ellos, verificando si la comparación es válida. Se tomaron muestras de suelo en 25 sitios de cultivo en Hapludox, los cuales se diferenciaron en el sistema de labranza, cultivo y / o manejo, en el municipio de Rio Paranaíba, MG, a diferentes profundidades. Los datos obtenidos se sometieron al análisis de correlación de Pearson. La correlación entre los anillos volumétricos para todas las variables fue significativa, descrita por las ecuaciones de correlación y = 0.3788 + 0.7054 * x (R = 0.68), y = 0.1342 + 0.6582 * x (R = 0.62) e y = 0.1107 + 0.6071 * x (R = 0,67), para las variables densidad, porosidad total y microporosidad, respectivamente. Se concluye que la comparación de valores de las variables determinadas a partir del muestreo con los dos anillos volumétricos ensayados es válida.

Abstract SPEED Stat is a new spreadsheet program for univariate statistical analyses, focused on the dominant profile of agricultural experimentation. The program can perform analysis of variance; tests for normality, homoscedasticity, additivity, outliers; complex contrasts; multiple comparison tests; Scott-Knott's grouping analysis; regression analysis; and others. It has available at speedstatsoftware.wordpress.com.

RESUMO Este trabalho foi realizado com o objetivo de avaliar os efeitos do revestimento com extrato de própolis de diferentes fontes botânicas sobre as características físico-químicas de banana ‘Prata’ (Musa sapientum L.), armazenada à temperatura ambiente. Bananas ‘Prata’ foram selecionadas e submetidas à cinco tratamentos pós-colheita, sendo quatro formas de revestimento por imersão em extrato de própolis de diferentes fontes botânicas com concentração de 2,5% (m/v) (“extrato aquoso de própolis do tipo silvestre”, “extrato hidroalcoólico de própolis do tipo silvestre”, “extrato hidroalcoólico de própolis do tipo verde alecrim e “extrato hidroalcoólico de própolis do tipo vermelho ”) e um controle (sem revestimento). As variáveis avaliadas foram perda de massa, firmeza da polpa, sólidos solúveis (SS), acidez titulável (AT), relação entre sólidos solúveis e acidez titulável (SS/AT) e potencial hidrogeniônico (pH), realizadas em intervalos de 3 dias por 12 dias de armazenamento. Realizou-se a análise sensorial das bananas aos 3 e 6 dias de armazenamento, avaliadas por 55 provadores não treinados através do teste de aceitação. Ao final de 12 dias de armazenamento, os revestimentos de extrato de própolis “verde” e “aquoso” reduziram a perda de massa em banana ‘Prata’, quando comparados ao tratamento pós-colheita “controle”. Neste mesmo período, não foi observado diferenças entre os tratamentos pós-colheita na firmeza da polpa dos frutos. Verificou-se a ocorrência de menores valores de AT e maiores valores de pH em todos os tratamentos pós-colheita no decorrer do amadurecimento dos frutos. O teor de SS aumentou ao final do período de armazenamento, que consequentemente, contribuiu para elevar a relação de SS/AT nos tratamentos pós-colheita, sendo mais significativo no tratamento pós-colheita “vermelho”. Sensorialmente, as bananas ‘Prata’ não apresentaram diferenças significativas entre os tratamentos pós-colheita com e sem revestimento de extrato de própolis, apresentando características sensoriais similares até o 6º dia de armazenamento.

ABSTRACT In the present work were evaluated the effects of propolis coatings of various botanical sources on quality traits of bananas cv. Prata (Musa sapientum L.) stored at room temperature. ´Prata´ bananas were selected and submitted to five postharvest treatments: four coatings applied by immersion in propolis extracts at a concentration of 2.5% (w/v) and a control (without coating). Propolis extracts were applied as 1) a wild type aqueous propolis extract, 2) a wild type hydroalcoholic propolis extract, 3) a rosemary green type hydroalcoholic propolis extract and 4) a red type hydroalcoholic propolis extract. The bananas were evaluated at three-day intervals along 12 days for fresh weight losses, flesh firmness, soluble solids (SS), titratable acidity (TA), the ratio SS/TA and pH. Sensory analyses were performed after three and six days of storage by 55 not trained panelists designed for acceptability. At the end of the twelve-day storage period, bananas coated either with the rosemary green hydroalcoholic extract or with the aqueous extract presented lower fresh weight losses in comparison to the bananas of the control treatment. No differences were determined in relation to flesh firmness and along the storage period TA values decreased and pH values increased in bananas of all treatments. SS contents increased towards the end of the storage period that, consequently, contributed to increases in the SS/TA ratio. The most significant increase in SS/TA ratio was determined in bananas coated with the red type hydroalcoholic extract. Taste panelists did not detect significant differences amongst coated and not coated cv. Prata bananas up to six days of storage.

ABSTRACT Experimental statistical procedures used in almost all scientific papers are fundamental for clearer interpretation of the results of experiments conducted in agrarian sciences. However, incorrect use of these procedures can lead the researcher to incorrect or incomplete conclusions. Therefore, the aim of this study was to evaluate the characteristics of the experiments and quality of the use of statistical procedures in soil science in order to promote better use of statistical procedures. For that purpose, 200 articles, published between 2010 and 2014, involving only experimentation and studies by sampling in the soil areas of fertility, chemistry, physics, biology, use and management were randomly selected. A questionnaire containing 28 questions was used to assess the characteristics of the experiments, the statistical procedures used, and the quality of selection and use of these procedures. Most of the articles evaluated presented data from studies conducted under field conditions and 27 % of all papers involved studies by sampling. Most studies did not mention testing to verify normality and homoscedasticity, and most used the Tukey test for mean comparisons. Among studies with a factorial structure of the treatments, many had ignored this structure, and data were compared assuming the absence of factorial structure, or the decomposition of interaction was performed without showing or mentioning the significance of the interaction. Almost none of the papers that had split-block factorial designs considered the factorial structure, or they considered it as a split-plot design. Among the articles that performed regression analysis, only a few of them tested non-polynomial fit models, and none reported verification of the lack of fit in the regressions. The articles evaluated thus reflected poor generalization and, in some cases, wrong generalization in experimental design and selection of procedures for statistical analysis.

A escolha da cultivar de cenoura deve ser planejada cuidadosamente pelo agricultor para o sucesso da exploração da cultura. O potencial produtivo da cultivar pode influenciar a demanda de nutrientes e deve ser conhecido para estabelecer o plano de fertilização. Objetivou-se, com este trabalho, avaliar o efeito de cultivares sobre a produtividade de cenoura, o teor e as quantidades alocadas de nutrientes em folhas e raízes. Foram implantados três experimentos em duas épocas de cultivo em Rio Paranaíba, MG. Na primeira época, caracterizada como verão típico, foram semeadas 10 cultivares de verão. Na segunda, evidenciada como verão-inverno (transição), instalaram-se dois experimentos, um com cultivares de verão; e outro, de inverno. Os tratamentos consistiram das cultivares de cenoura, distribuídos em blocos casualizados, com quatro repetições. Quantificaram-se a matéria fresca e a seca de raízes e folhas. Com base na matéria fresca de raízes, calculou-se a produtividade. Determinou-se o teor de nutrientes em folhas e raízes por ocasião da colheita. Calcularam-se, com bases nesses teores e na produção de matéria seca de raízes e folhas, a absorção e exportação de nutrientes. A maior média de produtividades total e comercial ocorreu no cultivo em condições de verão. A extração de N e K para a maioria das cultivares nos três experimentos superou as quantidades aplicadas via fertilizantes. Assim, houve contribuição dos nutrientes no solo para obter as produtividades alcançadas. Entretanto, para o P, a quantidade absorvida foi consideravelmente menor que a aplicada. Isso implicou que o solo teve sua fertilidade aumentada em P, após o cultivo. A época de cultivo e as cultivares influenciaram a produtividade, os teores de nutrientes nas folhas e raízes, a extração e a exportação de nutrientes pela cultura da cenoura.

Farmers must carefully choose the cultivar to be grown for a successful carrot crop. The yield potential of the cultivar may influence nutrient demand and should be known to plan for fertilization application. The aim of this study was to evaluate the cultivar effect on carrot yield and on the nutrient content and quantities allocated to leaves and roots. Three experiments were set up in two crop seasons in Rio Paranaíba, MG, Brazil. In the first season, typical summer, 10 summer cultivars were sown. In the second season, summer-winter (transition), two experiments were set up, one with summer cultivars and the other with winter cultivars. The treatments consisted of the carrot cultivars distributed in randomized blocks with four replications. Fresh and dry matter of the roots and leaves was quantified. Yield was calculated based on fresh matter of the roots. The nutrient content in leaves and roots was determined at the time of harvest. These contents and the dry matter production of roots and leaves were used to calculate nutrient uptake and export. The greatest average for total and commercial yield occurred in the crop under summer conditions. Extraction of N and K for most of the cultivars in the three experiments went beyond the amounts applied through fertilizers. Thus, there was contribution of nutrients from the soil to obtain the yields observed. However, the amount of P taken up was considerably less than that applied. This implies that soil P fertility will increase after cropping. The crop season and the cultivars influenced yield, nutrient content in the leaves and roots, and extraction and export of nutrients by the carrot crop.

No Brasil, as espécies Pinus elliottii e Terminalia ivorensis vêm sendo indicadas para reflorestamento. No entanto, pouco se sabe sobre as características ecológicas destas florestas, o ciclo de nutrientes e suas conseqüências sobre a produtividade e sustentabilidade sob condições tropicais. Visando melhor compreender a dinâmica do C nestes ecossistemas, objetivou-se neste trabalho avaliar a atividade microbiana do solo, serapilheira e da mistura solo + serapilheira em povoamentos florestais de P. elliottii e T. ivorensis. Amostras de solos e serapilheira foram incubadas e a atividade microbiana avaliada por meio da evolução de CO2. Ao final da incubação, a respiração acumulada foi superior para a serapilheira de T. ivorensis. Os demais substratos com serapilheira não diferiram entre si, mas diferiram do solo sob T. ivorensis, que, por sua vez, diferiu do solo sob P. elliottii. Nas condições testadas, a incorporação de solo à serapilheira, bem como a incorporação alternada de solo de um povoamento à serapilheira de outro, não promoveu aumentos significativos na respiração da serapilheira, mostrando que as características químicas da própria serapilheira alteram mais fortemente sua velocidade de degradação que as características químicas e microbianas do solo onde é incorporada.

In Brazil, the species Pinus elliottii and Terminalia ivorensis are being recommended for reforestation. However, little is known about the ecological characteristics of such forests, the nutrient cycle and possible consequences on yields and sustainability under tropical conditions. For a better understanding of the C dynamic in these ecosystems, this study aimed to evaluate the microbial activity of soil, litter, and the mixture of soil + litter in forest stands of P. elliottii and T. ivorensis. Samples of soil, litter and mixture were incubated and the microbial activity was evaluated on the basis of CO2 released. At the end of incubation, the accumulated respiration was significantly higher in litter of T. ivorensis. The other substrates with litter did not differ from each other, but differed from the soil under T. ivorensis, which in turn differed from soil under P. elliottii. In the tested conditions, the soil incorporation to litter, as well as the alternate incorporation of soil from one forest with the litter of another did not cause a significant increase in litter respiration. This indicates that the influence of the chemical characteristics of the litter itself on degradation speed is stronger than the chemical and microbiological characteristics of the soil where it is incorporated.