A qualidade e o preço de hortaliças são importantes fatores que interferem diretamente na aceitação comercial e intenção de compra por parte dos consumidores. Diante do exposto, objetivou-se avaliar a qualidade e o preço de três principais hortaliças (batata, cebola e cenoura) comercializadas no município de Chapadinha (MA) em supermercados, sacolões e feiras livres. Assim, realizou-se a coleta destas hortaliças para análise de qualidade (determinação da massa fresca, comprimento, diâmetro longitudinal, teor de sólidos solúveis e relação xilema/ floema) e de seus preços (R$ kg -1 ) em janeiro de 2016. Os caracteres de qualidade foram estudados através de estatística descritiva e os preços foram analisados pela aplicação do teste F e pela teoria do consumidor. As hortaliças apresentaram diferenças de qualidade para os diferentes segmentos de mercado, sendo que a feira livre é a melhor opção para compra de cebola e batata, enquanto, que a cenoura apresentou melhor padrão no segmento sacolão. Porém, quando considerado o critério de preço, o consumidor tenderá a escolher o supermercado para compra de cebola, ao passo que para batata e cenoura, o segmento sacolão apresentou-se como mais vantajoso economicamente. Portanto, considerando critérios de qualidade e de preço destas hortaliças, o segmento sacolão constitui a melhor opção para a compra destes produtos.Palavras-chave: cenoura, cebola, batata, supermercado, sacolão, feira livre.Analysis of the quality and price of vegetable marketed in retail market of Chapadinha/MA, Brazil. The quality and price of vegetables are important factors that directly interfere in the commercial acceptance and intention to buy by the consumers. Considering the above, the objective of this work was to evaluate the quality and price of three main vegetables (potatoes, onions and carrots) marketed in the municipality of Chapadinha (MA) in supermarkets, greengrocers and free fairs. Vegetables were collected and assessed for quality (determination of fresh mass, length, longitudinal diameter, soluble solids content (ºBrix) and xylem / phloem ratio) and their prices (R$ kg -1 ) in January 2016. Quality parameters were studied through descriptive statistics and prices were compared by F test and the consumer theory. Vegetables showed quality differences according to the market segments. Free fair was the better option for onion and potato purchase, while the carrot had better standard in the greengrocers. However, when considered the price criterion, it was clear that the consumer will tend to choose the supermarket to buy onion, while for potato and carrot the greengrocers was more economically advantageous. Therefore, considering quality and price criteria, the greengrocers seems to be the best choice to buy theses vegetables.

AbstractThe prediction of seed longevity (P50) is traditionally performed by the use of the Probit model. However, due to the fact that the survival data are of binary origin (0,1), the fit of the model can be compromised by the non-normality of the residues. Consequently, this leads to prediction losses, despite the data being partially smoothed by Probit and Logit models. A possibility to reduce the effect of non-normality of the data would be to apply the principles of the central limit theorem, which states that non-normal residues tend to be normal as the n sample is increased. The Logit and Probit models differ in their normal and logistic distribution. Therefore, we developed a new estimation procedure by using a small increase of the n sample and tested it in the Probit and Logit functions to improve the prediction of P50. The results showed that the calculation of P50 by increasing the n samples from 4 to 6 replicates improved the index of correctness of the prediction. The Logit model presented better performance when compared with the Probit model, indicating that the estimation of P50 is more adequate when the adjustment of the data is performed by the Logit function.

The identification of superior genotypes in plant breeding programs is not a quick and simple task and requires breeders to become aware of more suitable and efficient tools for evaluating crop performance. Univariate analyses are often too narrow for the scope of plant breeding because it lacks consideration of relations between variables. Therefore, the objective of this study was to select castor bean hybrids based on principal component analysis (PCA). Trials were conducted in 2017 with 31 hybrids in a randomized block design with 4 replications. The following variables were used to evaluate crop performance: plant height (PH), insertion height of the primary raceme (HPR), number of stem nodes (NN), number of racemes (NR), number of seeds (NS), stem diameter (SD), number of fruits (NF), 100-seed weight (S100) and seed oil content (SOC). The first three principal components (PCs) explained approximately 75.01 % of all the variability in the dataset. PC 1, 2 and 3 were particularly related to productivity (NS, NR, S100 and NF), plant size (SD, HPR and PH) and oil production (SOC), respectively. Hybrids 14 and 23 were the most suitable for grain production in commercial scale due to short-height, which favors mechanical harvesting. Commercial hybrid 26 showed high SOC, medium grain yield and medium-height.

Seed longevity is characterized as the time for which seed remains viable during storage. Seed longevity can be estimated by a Probit model that determines the period in which 50% of seeds have lost viability (P 50 ). The transformed data are binary and when they are not normally distributed, it is necessary to modify the Probit model or apply other functions to estimate longevity. This work aimed studied the use of the Logit, Cauchy, and Cauchy-Santos-Sartori-Faria (Cauchy-SSF) functions to estimate the longevity of soybean seed [Glycine max (L.) Merr.] and compared Probit longevity models for the ordinary least squares (OLS) adjustment method and the generalized linear model (GLM). Ten seed lots were used to estimate water content, germination, and longevity. The P 50 data were transformed via the Probit, Logit, Cauchy, and Cauchy-SSF functions to estimate the coefficients of determination, the Akaike information criterion, deviance, dispersion, and the regression residuals. The effect on the results was observed, depending on the link function. The Cauchy-SSF function as part of the OLS method estimated longevity in eight seed lots within the interval of interest (II), and the Cauchy function as part of the GLM estimated longevity in nine seed lots. The Cauchy, Cauchy-SSF, and Logit models were capable of estimating the longevity of soybean seeds (P 50 ) slightly better than the Probit model. We suggest the Cauchy-SSF function for the OLS method and the Cauchy function for the GLM method to estimate soybean seed longevity when the data are not normally distributed. core Ideas• The Cauchy, Cauchy-Santos-Sartori-Faria Cauchy-SSF, and Logit functions estimated longevity in soybean seeds more robustly than the Probit function. • The ordinary least squares method combined with the Cauchy-SSF function is as good as the generalized linear model method with the Cauchy function. • The selection of the function changes the estimated time when 50% of seeds have lost viability, emphasizing the importance of the correct choice.Abbreviations: Cauchy-SSF, Cauchy-Santos-Sartori-Faria; GLM, generalized linear model; II, interval of interest; OLS, ordinary least squares; P 50, period in which 50% of seeds have lost viability, σ, standard deviation. bIoMetrY, ModeLInG, And stAtIstIcsPublished in Agron.

Tomato (Solanum lycopersicum L.) is a crop whose cultivation is of great importance in economic and social aspects. However, the development of efficient and low-cost technologies is essential for the growth of agricultural activity in the region. Among the most studied technologies, the production of quality seedlings in organic substrates is highlighted. In this context, the objective was to evaluate the development of tomato seedlings produced with organic substrates, using the decomposed stem of babassu palm and goat manure, using the multidimensional technique with the help of canonical functions associated with growth analysis. The treatments consisted of 25%, 50% and 75% sand aggregates, 25% to 50% sand addition, 25% to 50% sand and commercial substrate, established in a completely randomized design with 28 treatments and four replications in a 7 × 4 factorial scheme, the first factor consisting of seven substrates and the second of four evaluation periods (7, 14, 21, 28 days after emergence). Were analyzed shoot length and main root length; dry mass of the aerial part and of the root system and leaf area. These variables were analyzed through multidimensional analysis with the help of canonical functions and growth analysis. In general, the substrates consisting of goat manure and sand were superior to the substrates consisting of the decomposed palm tree stem and the commercial substrate. The alternative substrate formed by the mixture of goat manure, in the proportion of 25% of sterilized sand + 75% goat manure, constitutes the best option for the production of tomato seedlings.

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The use of seeds with high physiological quality allows rapid growth and establishment of seedlings in the field to be obtained. Therefore, the accuracy of the information obtained during the determination of the physiological quality of seeds is of great importance. The objective was to use generalized linear models, investigating which link function (Probit, Logit and Complementary log-log) is suitable to predict T50 and uniformity during germination of soybean and corn seeds. To perform the experiments, we used seeds from five commercial hybrids and/or cultivars of corn and soybean. The germination speed was calculated by counting the germinated seeds and the results were expressed in the form of proportions. Germination uniformity was calculated by the difference in the times required for germination. The best model was selected according to the criteria of the test of Deviance, AIC and BIC. The Logit model showed accurate results for most cultivars. The evaluation of germination in the form of proportions considering the assumption of binomial response is satisfactory, and the choice of the link function is dependent on the characteristics of each lot and/or species evaluated. The use of this methodology makes it possible to estimate any germination time and uniformity.

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