Optimum Plot Size and Number of Replications in Papaya Field Experiment

Abstract

ABSTRACT-The aim of this study was to estimate the optimum plot size and number of replications in papaya field experiments. Eleven variables were evaluated in four cultivars of papaya with planting in different seasons between 2011 and 2013 in the north of the Espírito Santo state. Analysis were made from blank test applied to 240 selected for planting season and cultivate plants in commercial fields. The determination of optimum plot size was performed by applying the methodologies of modified maximum curvature and maximum curvature of coefficient of variation. The determination of the number of repetitions was taken from the least significant difference in average 20% and 30%. The optimum plot size proved the same by the two methods studied for most evaluations. The optimum size required differs among cultivars, between variables and between planting seasons, with the largest number of plants was required for the variables number of fruits per plant and yield per plant. We conclude that the optimal number of papaya plants planted in the field is six plants per plot using three replications. Index terms: Carica papaya L., experimental precision, experimental planning. TAMANHO ÓTIMO DE PARCELAS E NÚMERO DE REPETIÇÕES EM EXPERIMENTOS DE CAMPO COM MAMOEIRORESUMO-Objetivou-se neste estudo estimar o tamanho ótimo de parcelas e o número de repetições em mamoeiro cultivado a campo. Avaliaram-se onze variáveis em quatro cultivares de mamoeiro com plantio em diferentes estações do ano entre 2011 e 2013 no norte do Espírito Santo. As análises foram feitas a partir de ensaio em branco aplicado em 240 plantas selecionadas, por época de plantio e por cultivar, em lavouras comerciais. A determinação do tamanho ótimo de parcela foi feita aplicando-se as metodologias de máxima curvatura modificado e máxima curvatura do coeficiente de variação. A determinação do número de repetições foi feita a partir da diferença mínima significativa da média de 20% e 30%. O tamanho ótimo da parcela se mostrou o mesmo pelas duas metodologias estudadas para a maioria das avaliações. O tamanho ótimo requerido difere entre as cultivares, entre as variáveis e entre as épocas de plantio, sendo que o maior número de plantas foi requerido para as variáveis número de frutos por planta e produção por planta. Concluiu-se que o número ótimo de plantas em experimentos de mamoeiro plantados a campo é de seis plantas por parcela com uso de três repetições. Termos para indexação: Carica papaya L., precisão experimental, planejamento experimental.

Optimum plot size for experiments with papaya genotypes in field

“…Schmildt et al (2016) suggested 6 plants per plot using 3 replications and a difference of 30% between means (d), similar to the results obtained in this work using 25 to 35 genotypes per block (Table 4). However, for better use of the experimental area, it is recommended to design experiments with four replications and four plants per plot because this will require 16 plants per genotype, while using only 3 replicates of 6 plants per plot it require 18 plants per genotype.…”

“…In papaya, the experimental plot size has been determined for comparing seedlings performance in greenhouses (Lima et al, 2007;Brito et al, 2012;Celanti et al, 2016 a, b) and also for adult plants in the open field (Schmildt et al, 2016), but all these works were performed with blank test, test that evaluates only one genotype at a time.…”

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

“…These results differed from those of SCHMILDT et al (2016), who conducted a field experiment evaluating the THB and Golden varieties of papaya and the F1 of Tainung and Uenf/Caliman 01 hybrids using a similar methodology and reported 6 bu and 4 bu, corresponding to the morpho-agronomic Figure 1 -The relationship between the coefficient of variation (CV) and the optimal plot size (Xbu) in basic units (bu) obtained using the maximum modified curvature method for the morpho-agronomic traits of plants (Carica papaya L.). Silva et al traits and fruit quality.…”

Optimal plot size for experimental trials with Opuntia cactus pear

“…The dimensioning of the plots from the basic unit formation components, CVe, index b, d, t and r, establish similarity between the variables, mainly due to the influence of the CVe and the difference to be detected -d, since it configures a direct relationship between the variability of the data and the size of the plot (Smith, 1938;Hatheway, 1961), a fact supported in several studies (Schmildt et al, 2016;Sousa et al, 2016;Lavezo et al, 2017;Cargnelutti Filho et al, 2018). However, the lower required experimental accuracy -d, implies reduced BEUs.…”

“…The estimation of plot sizes by the statistical proposal of Hatheway (1961) was investigated in several studies (Cargnelutti Filho, Toebe, Burin, Casarotto, & Alves, 2014;Schmildt, Schmildt, Cruz, Cattaneo, & Ferreguetti, 2016;Lavezo et al, 2017; with wide recommendation for the use of smaller plots with a greater number of replications to reach the maximum experimental accuracy and, with this, a greater efficiency in the use of the area. These results reinforce the need to plan smaller and more efficient experiments on accuracy and costs.…”