RESUMO: Os objetivos deste trabalho foram ajustar os modelos Gompertz e Logístico para as massas de matéria fresca e seca de folhas, e as massas de matéria fresca e seca de parte aérea de três cultivares de alface e indicar o modelo que melhor descreve o crescimento no outono-inverno. As cultivares de alface Gloriosa, Pira Verde e Stella, foram avaliadas no outono-inverno de 2016 e outono-inverno de 2017, em cultivo sem solo em ambiente protegido. Após o transplante, a cada sete dias, foram pesadas as massas de matéria fresca e seca de folhas e as massas de matéria fresca e seca de parte aérea. Essas variáveis dependentes foram ajustadas em função da soma térmica acumulada. Foram estimados os parâmetros dos modelos Gompertz e Logístico, verificados os pressupostos dos modelos, calculados os indicadores de qualidade do ajuste e os pontos críticos e quantificadas as medidas de curvatura intrínseca e de parametrização. Os modelos Logístico e Gompertz apresentam ajuste satisfatório para as massas de matéria fresca e seca de folhas e para as massas de matéria fresca e seca de parte aérea, para as cultivares de alface Gloriosa, Pira Verde e Stella, no outono-inverno. O modelo Logístico é o que melhor descreve o crescimento das cultivares de alface.

ABSTRACT: The objectives of this study were to fit the Gompertz and Logistic models for the fresh and dry matter of leaves and the fresh and dry matter of shoots of three lettuce cultivars and indicate the best model to describe their growth in autumn-winter. The lettuce cultivars Gloriosa, Pira Verde, and Stella were evaluated in the autumn-winter of 2016 and 2017, in soilless in a protected environment. After transplantation, the fresh and dry matter of leaves and shoots were weighed every seven days. These dependent variables were fit using the accumulated thermal sum. The parameters of the Gompertz and Logistic models were estimated, the assumptions of the models were verified, the indicators of fit quality and critical points were calculated and the parametric and intrinsic curvature measures quantified. The Logistic and Gompertz models presented a satisfactory adjustment for the fresh and dry matter of leaves and the fresh and dry matter of shoots, for the lettuce cultivars Gloriosa, Pira Verde and Stella, in autumn-winter. The Logistic model best describes the growth of the lettuce cultivars.

O objetivo deste trabalho foi determinar a dimensão da amostra (número de plantas) para estimar a média de caracteres de centeio, avaliados no período de colheita dos grãos. Foram conduzidos oito ensaios de uniformidade (experimentos em branco). Cinco com a cultivar ‘BRS Progresso’ e três com a cultivar ‘Temprano’. No estágio de maturação dos grãos, foram recolhidas, aleatoriamente, 780 plantas (total dos oito ensaios) e avaliados 17 caracteres em cada planta. Foram calculadas estatísticas descritivas e determinou-se a dimensão da amostra para estimar a média, para as amplitudes do intervalo de confiança de 95% (ACI95%) de 5 (maior precisão), 10, 15, 20, 25 e 30% (menor precisão) da média - por reamostragem com reposição. Há variabilidade da dimensão da amostra entre caracteres, cultivares e épocas de sementeira. A dimensão da amostra para a cultivar ‘BRS Progresso’ é menor que para a cultivar ‘Temprano’. Para a estimação da média, para todos os caracteres e épocas de sementeira, com ACI95% máxima de 15, 20, 25 e 30%, são necessárias 352, 197, 127 e 87 plantas da cultivar ‘BRS Progresso’ e 609, 341, 227 e 154 plantas da cultivar ‘Temprano’, respectivamente.

The objective of this work was to determine the sample size (number of plants) to estimate of the mean rye traits, evaluated in the grain harvest period. Eight uniformity trials (blank experiments) were conducted. Five with the cultivar ‘BRS Progresso’ and three with the cultivar ‘Temprano’. At the stage of grain maturation 780 plants (total of eight trials) were randomly collected and 17 traits were evaluated in each plant. Descriptive statistics were calculated and the sample size to estimate the mean at amplitudes of the confidence interval of 95% (ACI95%) 5 (greater precision), 10, 15, 20, 25, and 30% (lower precision) of the mean - was determined by resampling with replacement. There is variability of sample size between traits, cultivars, and sowing dates. The sample size for the cultivar ‘BRS Progresso’ is lower than for the cultivar ‘Temprano’. For the mean estimate, for all traits and sowing dates, with ACI95% maximum of 15, 20, 25, and 30% of the mean, 352, 197, 127, and 87 plants of ‘BRS Progresso’ cultivar and 609, 341, 227, and 154 plants of the ‘Temprano’ cultivar are required, respectively.

RESUMO: O objetivo deste trabalho foi verificar a influência do tamanho da unidade experimental básica (UEB) na estimativa do tamanho ótimo de parcela, para a avaliação da massa de matéria verde de crotalária juncea (Crotalaria juncea L.), pelo método da máxima curvatura modificado. Avaliou-se a massa de matéria verde de crotalária juncea, no florescimento da cultura, em ensaios de uniformidade conduzidos em duas épocas de semeadura. Em cada época foram avaliadas 4.608 UEB de 0,5×0,5m (0,25m2) e formaram-se 36 planos de UEB com tamanhos entre 0,25 e 16m2. Em cada época, para cada plano de UEB, com os dados de massa de matéria verde, estimou-se o tamanho ótimo de parcela, pelo método da máxima curvatura modificado. A estimativa do tamanho ótimo de parcela depende do tamanho da unidade experimental básica. É indicado avaliar a massa de matéria verde em UEB de menor tamanho possível, para serem usadas na estimação do tamanho ótimo de parcela.

ABSTRACT: This study aimed to verify the influence of the basic experimental unit (BEU) size in the estimation of the optimum plot size to evaluate the fresh matter of sunn hemp (Crotalaria juncea L.) using the modified maximum curvature method. The fresh matter of sunn hemp was evaluated in uniformity trials in two sowing season in flowering. In each sowing season, 4,608 BEUs of 0.5×0.5m (0.25m2) were evaluated and 36 BEU plans were formed with sizes from 0.25 to 16m2. In each evaluation period for each BEU plan, using fresh matter data, optimum plot size was estimated through the modified maximum curvature method. Estimation of the optimum plot size depends on the BEU size. Assessing fresh matter in BEUs that are as small as possible is recommended in order to use it to estimate the optimum plot size.

ABSTRACT The objectives of this work were to determine the optimum plot size and number of repetitions to evaluate the fresh matter weight of vetch (Vicia sativa L.) in sowing densities. Fortyeight uniformity trials of 6 m × 6 m were conducted. Sixteen trials were evaluated in each sowing density (40, 60, and 80 kg∙ha−1). Each trial was divided into 36 basic experimental units (BEU) of 1 m × 1 m, totaling 1,728 BEU. In each BEU, the fresh matter was weighed. The optimum plot size was determined by the method of maximum curvature of the coefficient of variation model. The means were compared among sowing densities by the Scott-Knott’s test. The number of repetitions — for experiments with completely randomized and randomized block designs, in scenarios of i treatments (i = 3, 4, …, 50) and d minimal differences between treatments means being detected as significant with 5% probability by Tukey’s test, expressed in percentage of the experiment average (d = 10%, 11%, …, 20%), was determined by iterative process until convergence. The optimum plot size to evaluate the fresh matter weight of vetch is 4.52 m2 at the 3 sowing densities. Four repetitions, to evaluate up to 50 treatments, in completely randomized and randomized block designs, are enough to identify as significant, at 5% probability by Tukey’s test, differences between treatment means of 29.15% of the experiment average.

Abstract Phyllochron and leaf appearance rate are both important parameters in the production efficiency of agricultural crops. The objectives of this study were to determine the phyllochron and leaf appearance rate in 4 oat cultivars (Avena sativa L.) in 3 sowing dates and verify the variability of phyllochron and leaf appearance rate among cultivars and sowing dates. The experimental design was the completely randomized with 12 treatments and 20 repetitions. Treatments were formed by the combination of 4 cultivars (URS Charrua, URS Taura, URS Estampa, and URS Corona) and 3 sowing dates in 2014 (April 28, May 28, and July 14). In each plant (repetition) of each treatment, the number of expanded leaves (NEL) was counted 3 times per week from the first leaf emission until flowering. For each plant, cultivar, and sowing date, linear regression was adjusted between NEL and accumulated thermal time (ATT) and between NEL and number of days after emergence (DAE). Phyllochron was determined by the inverse of the angular coefficient of the linear regression between the NEL and ATT. The leaf appearance rate was determined by the inverse of the angular coefficient of the linear regression between NEL and DAE. In oat, there is variability of phyllochron and leaf appearance rate among cultivars and sowing dates. Phyllochron oscillates between 95.88 and 117.70 °C day∙leaf−1 and leaf appearance rate, between 6.41 and 9.65 days∙leaf−1. The oat cropping management in function of phyllochron and leaf appearance rate is dependent on cultivars and sowing dates.