Dimensionamento Amostral para Avaliação de Altura e Diâmetro de Plantas de Timbaúva

Abstract

RESUMOO objetivo do estudo foi estimar o tamanho de amostra para avaliar a altura de planta (H), o diâmetro do coleto (D) e a relação altura de planta/diâmetro do coleto (HD) de timbaúva (Enterolobium contortisiliquum) e verificar a variabilidade do tamanho de amostra entre tubetes, doses de fertilizante e idades de avaliação. Foram avaliados dez tratamentos, formados pela combinação de tamanhos de tubetes (110 e 180 cm3 ) e doses de fertilizante (0, 3, 5, 7 e 9 g L -1 de substrato), no delineamento em blocos, com quatro repetições. Em cinco idades foram determinadas H, D e HD. O tamanho de amostra para H, D e HD é dependente da idade de avaliação. Para os tamanhos de tubetes, doses de fertilizante e idades de avaliação, 22 plantas por unidade experimental (bandeja) são suficientes para estimar a média dessas características, para erro de estimação de 10% da média, com grau de confiança de 95%. Palavras-chave:Enterolobium contortisiliquum, número de plantas, amostragem. Sample Size for Height and Diameter Evaluation of Timbauva Plants ABSTRACTThe objective was to estimate the sample size to evaluate height (H), collar diameter (D) and relation height/collar diameter (HD) of timbauva plants (Enterolobium contortisiliquum) and to verify its variability among tubes, dosages of fertilizer and ages of evaluation. Ten treatments were organized in blocks designed with four replication and formed by the combination of sizes of tubes (110 and 180 cm 3 ) and dosages of fertilizer (0, 3, 5, 7 e 9 g L -1 of substrate). The H, D and HD variables were evaluated in five ages. The sample size to evaluate H, D and HD is dependent on age evaluation. For the tubes, dosages of fertilizer and ages of evaluation, 22 plants per experimental unit (pot) are enough to predict the plants variables, with estimation error equal to 10% of estimated average, with a reliable rating of 95%.

Optimal plot size for experimental trials with Opuntia cactus pear

“…The CVe presented a directly proportional relationship to the plot size, as expected, since the greater percentage variation of the evaluated characteristic indicates the need for a larger experimental area to detect a significant difference between the treatments (Cargnelutti Filho et al, 2018).…”

“…The coefficients of experimental variation (CVe) reflect the natural and specific variability in the evaluated characteristic. However, it can be influenced mainly by the soil conditions and the agricultural management of the BEU, which directly influences the experimental accuracy (Cargnelutti Filho et al, 2018). Pimentel-Gomes (2009) classified the experimental accuracy using CVe, so that values lower than 10%, between 10 and 20%, between 20.01 and 30% and greater than 30%, indicate, in this order, high, medium, low and very low experimental accuracy.…”

“…These studies, despite the relevance to the semi-arid region, reveal some disagreements on the experimental arrangement, number of replications and size of the experimental unit used (Queiroz et al, 2015;Silva et al, 2016). Thus, it is necessary to improve the agricultural research with cactus pear in order to obtain information on the number of replications, size and shape of the experimental plots to achieve results that allow detecting significant differences between tested treatments (Cargnelutti Filho, Storck, Lúcio, Toebe, & Alves, 2016;Cargnelutti Filho, Araujo, Gasparin, & Foltz, 2018).…”

“…The ideal size of the experimental plot can be established considering soil heterogeneity index -SHI (Smith, 1938;Cargnelutti Filho et al, 2016), genetic material or studied crop (Sousa, Silva, & Assis, 2016), balance between accuracy and costs (Cargnelutti Filho et al, 2016;Sousa et al, 2016), nature of the experimental material, number of replicates and evaluation methods (Cargnelutti Filho et al, 2018).…”

Optimal size of experimental plots of papaya trees using a modified maximum curvature method

“…Researchers used different methods with crops to minimize experimental error, which may occur because of several factors, such as the choice of design, plot loss, crop cycle, number of treatments, and crop treatments. The determination of plot size in different crops is one way to increase experimental accuracy, allowing for the minimization of time, optimization of resources, and guaranteeing maximum accuracy in an experiment (SILVA et al, 2012;CARGNELUTTI FILHO et al, 2018).…”