Cirineu Tolfo Bandeira

Plot size related to numbers of treatments and replications, and experimental precision in dwarf pigeon pea

The aim of this study was to determine the optimum plot size to evaluate the fresh matter of aerial part of dwarf pigeon pea (Cajanus cajan (L.) Millsp), cultivar IAPAR 43 (Aratã), in scenarios formed by combinations of numbers of treatments, number of replications, and precision levels. The fresh matter of aerial part was weighed on basic experimental units of 1 m × 1 m in three uniformity trials with size of 24 m × 12 m (288 m2 in each trial). The soil heterogeneity index of Smith was estimated. Also, the optimum plot size was determined by Hatheway’s method in scenarios formed by combinations of BASIC AREAS Article Plot size related to numbers of treatments and replications, and experimental precision in dwarf pigeon pea Alberto Cargnelutti Filho1*, André Lavezo2, Cláudia Marques de Bem2, Fernanda Carini2, Denison Esequiel Schabarum2, Cirineu Tolfo Bandeira2, Jéssica Andiara Kleinpaul2, Cleiton Antonio Wartha3, Daniela Lixinski Silveira2, Rafael Vieira Pezzini2, Rosana Marzari Thomasi1, Fernanda Martins Simões1, Ismael Mario Márcio Neu2 1.Universidade Federal de Santa Maria Departamento de Fitotecnia Santa Maria (RS), Brazil. 2.Universidade Federal de Santa Maria Programa de Pós-Graduação em Agronomia Santa Maria (RS), Brazil. 3.Universidade Federal de Viçosa Programa de Pós-Graduação em Fitotecnia Viçosa (MG), Brazil. *Corresponding author: alberto.cargnelutti.filho@gmail.com Received: Mar. 15, 2017 – Accepted: May 29, 2017 i treatments (i = 5, 10, 15, and 20), r replications (r = 3, 4, 5, 6, 7 8, 9, and 10), and d precision levels (d = 5%, 10%, 15%, 20%, 25%, and 30%). In experiments designed on randomized block design with 5 to 20 treatments and four replications, plots with 9 m2 were enough to identify significant differences among treatments regarding the fresh matter of aerial part in dwarf pigeon pea at 5% probability of 30% of the experiment overall mean.

Sample size for estimating mean and coefficient of variation in species of crotalarias

The objective of this study was to determine the sample size necessary to estimate the mean and coefficient of variation in four species of crotalarias (C. juncea, C. spectabilis, C. breviflora and C. ochroleuca). An experiment was carried out for each species during the season 2014/15. At harvest, 1,000 pods of each species were randomly collected. In each pod were measured: mass of pod with and without seeds, length, width and height of pods, number and mass of seeds per pod, and mass of hundred seeds. Measures of central tendency, variability and distribution were calculated, and the normality was verified. The sample size necessary to estimate the mean and coefficient of variation with amplitudes of the confidence interval of 95% (ACI95%) of 2%, 4%, ..., 20% was determined by resampling with replacement. The sample size varies among species and characters, being necessary a larger sample size to estimate the mean in relation of the necessary for the coefficient of variation.

Leaf area estimation from linear measurements in different ages of Crotalaria juncea plants

The goal of this study was to estimate the leaf area of Crotalaria juncea according to the linear dimensions of leaves from different ages. Two experiments were conducted with C. juncea cultivar IAC-KR1, in the 2014/2015 sowing seasons. At 59, 82, 102, 129 days after sowing (DAS) of the first and 61, 80, 92, 104 DAS of the second experiment, 500 leaves were collected, totaling 4,000 leaves. In each leaf, the linear dimensions were measured (length, width, length/width ratio and length × width product) and the specific leaf area was determined through Digimizer and Sigma Scan Pro software, after scanning images. Then, 3,200 leaves were randomly separated to generate mathematical models of leaf area (Y) in function of linear dimension (x), and 800 leaves for the models validation. In C. juncea, the leaf areas determined by Digimizer and Sigma Scan Pro software are identical. The estimation models of leaf area as a function of length × width product showed superior adjustments to those obtained based on the evaluation of only one linear dimension. The linear model Ŷ=0.7390x (R2=0.9849) of the real leaf area (Y) as a function of length × width product (x) is adequate to estimate the C. juncea leaf area.