ABSTRACT This study aimed to evaluate the use of the product of thermal efficiency and photosynthetically active radiation (TEP) to model the growth of tomato seedlings across different growing seasons. The work was conducted in a completely randomized design with four replicates in two seasons (summer/autumn and winter/spring). Height, diameter, the Dickson’s Quality Index (DQI), and total plant mass (TPM) were measured at 15, 20, 25, 30, 35 and 40 days after sowing (DAS). The logistic model was fitted for each measured variable as a function of TEP, and the partial derivatives of the fitted function estimated the critical points. The results demonstrated that the logistic function effectively explained the nonlinear relationships of seedling growth. The fit quality parameters showed high fitted coefficients of determination and low values for the standard error of fit, residual standard deviation, and intrinsic and parametric nonlinearity. It was possible to characterize the growth process of tomato seedlings in both growth periods investigated. The logistic model fitted for the studied variables as a function of TEP becomes an accurate model capable of describing growth aspects of tomato seedlings, such as growth estimation, growth speed, and growth rate, essential parameters for decision-making in tomato cultivation. (TEP summer/autumn summerautumn summer autumn winter/spring. winterspring winter/spring . winter spring winter/spring) Height diameter Dicksons Dickson s DQI, DQI , (DQI) TPM (TPM 15 20 25 30 3 4 DAS. DAS (DAS) points deviation nonlinearity investigated estimation speed rate decisionmaking decision making cultivation (DQI 1 2 (DAS

ABSTRACT The flaxseed is little explored under Brazilian cultivation conditions, generating a gap in information about the appropriate management of the crop, in the country. Hence, the objective was to find the appropriate dose of nitrogen for the development of the variables: technical length, yield length, main stem diameter, number of grains per pod, plant grain yield, and plant dry mass of two flaxseed varieties, brown and golden, in places with subtropical and tropical climate in Brazil. The treatments consisted of a two-factor 2 x 6 experiment, consisting of two flax varieties (brown and golden) and six nitrogen doses (0; 30; 60; 90; 120 and 150 kg ha-1), in randomized blocks with four repetitions and three different environments: Santa Maria and Frederico Westphalen, in the state of Rio Grande do Sul, and Viçosa, in the state of Minas Gerais. The brown variety obtained greater technical and yield length compared to the golden variety, on the other hand, the golden variety showed a higher number of grains per capsule and higher plant grain yield compared to the brown variety, in the three environments. The plant dry mass increased linearly and proportionally to the increase in nitrogen doses in Santa Maria and Frederico Westphalen environments. Therefore, flaxseed responds differently to nitrogen supplementation according to the cultivation environment, showing wide variability. The different doses of nitrogen influenced the variables analyzed and the varieties of flaxseed differently, depending on the environment. conditions crop country Hence diameter pod Brazil twofactor factor experiment 0 (0 30 60 90 12 15 ha1, ha1 ha 1 , ha-1) environments Sul Viçosa Gerais hand Therefore environment variability ( 3 9 ha-1 ha-

RESUMO Uma das formas de otimizar a avaliação do experimento e obter elevada precisão dos resultados é com o uso de quantidade adequada de mensurações para cada variável observada no experimento. Neste sentido, o objetivo deste estudo foi estimar coeficiente de repetibilidade e o número de mensurações necessárias para análise de caracteres de produção de abobrinha, pepino, pimenta biquinho e ervilha. Os experimentos foram realizados no Departamento de Fitotecnia da Universidade Federal de Santa Maria. Para abobrinha e pepino avaliaram-se as variáveis número, massa e comprimento de frutos, maior e menor diâmetro dos frutos. Para ervilha avaliou-se o número, massa e comprimento de vagens, número e massa de grãos, e para pimenta biquinho avaliou-se número, massa, maior diâmetro e o comprimento dos frutos. O coeficiente de repetibilidade (r) foi estimado pelo método dos componentes principais usando a matriz de correlação e a matriz de covariâncias. Determinou-se ainda, o número de mensurações para cada variável com base nos coeficientes de determinação de 0.80, 0.85, 0.90, 0.95 e 1.00. O coeficiente de repetibilidade estimado obteve as maiores estimativas com o uso da matriz de covariâncias, variando de 0,67 a 0,84 para abobrinha, de 0,66 a 0,97 para pepino, de 0,47 a 0,70 para ervilha e de 0,57 a 0,71 para pimenta biquinho. Para avaliar a massa de frutos em abobrinha, pepino, ervilha e pimenta biquinho, são necessárias, respectivamente 7, 4, 8 e 8 mensurações para um coeficiente de determinação de 95%.

ABSTRACT One of the ways to optimize the evaluation of the experiment and obtain high precision of the results is with the use of an adequate number of measurements for each variable observed in the experiment. In this sense, the objective of this study was to estimate the repeatability coefficient and the number of measurements necessary for the analysis of characters of production of zucchini, cucumber, pout pepper and pea. In the experiments carried out with zucchini and cucumber the variables number of fruits, fruit mass, fruit length, largest fruit diameter and smallest fruit diameter were evaluated. For pea the number, length and mass of pods, number and mass of grains per pod and for pout pepper number and mass of fruits, largest fruit diameter and length were evaluated. The repeatability coefficient (r) was estimated by the principal component method using the correlation matrix and the covariance matrix. The number of measurements for each variable was also determined based on the coefficients of determination of 0.80, 0.85, 0.90, 0.95 and 1.00. The estimated repeatability coefficient obtained the highest estimates using the covariance matrix, ranging from 0.67 to 0.84 for zucchini, from 0.66 to 0.97 for cucumber, from 0.47 to 0.70 for pea and from 0.57 to 0.71 for pout pepper. To evaluate the fruit mass in zucchini, cucumber, pea and pout pepper, are exactly, respectively, 7, 4, 8 and 8 measurements for a coefficient of determination of 95%.

RESUMO: O objetivo deste trabalho foi avaliar as relações entre os caracteres biométricos de mudas de tomate com os caracteres de produção obtidos ao final do ciclo da cultura, para determinar como a qualidade das mudas interfere na produtividade do tomate. O experimento foi conduzido em duas épocas de cultivo, em delineamento inteiramente casualizado, com quatro repetições e a unidade experimental composta por cinco plantas. Os tratamentos foram constituídos por mudas com diferentes idades, diferenciadas pelos dias após a semeadura (DAS): (15, 20, 25, 30, 35 e 40 DAS). Após cada avaliação das mudas, eram transplantadas para o local de produção definitivo, sendo avaliadas até o final do ciclo. Avaliaram-se os caracteres biométricos das mudas e os caracteres da produção de frutos. Análise de correlação de Pearson e componentes principais (PCA) foram realizados para determinar as relações entre os caracteres, análise de trilha para determinar os efeitos diretos e indiretos e análise de correlações canônicas entre os grupos de caracteres. Em todas as análises realizadas, foi identificada correlação fraca entre os caracteres biométricos das mudas (que avaliam a qualidade) com os caracteres da produção de frutos de tomate em cultivo em substrato.

ABSTRACT: This study evaluated the relationships between the biometric characters of tomato seedlings with the production characters obtained at the end of the crop cycle, to determine how the quality of seedlings interferes with tomato productivity. An experiment was carried out in two growing seasons, in a completely randomized design, with four replications and the experimental unit consisting of five plants. The treatments consisted of seedlings with different ages, differentiated by the days after sowing (DAS): (15, 20, 25, 30, 35, and 40 DAS). After each evaluation of the seedlings, they were transplanted to the definitive production site, being evaluated until the end of the cycle. Biometric characters of seedlings and characters of fruit production were evaluated. Pearson correlation analysis and principal components (PCA) were performed to determine the relationships between the characters, path analysis to determine the direct and indirect effects, and analysis of canonical correlations between the groups of characters. In all analyses performed, weak correlation between the biometric characters of the seedlings (which evaluate the quality) with the characters of tomato fruit production in substrate cultivation was identified.