Estimation of optimum experimental plot size for taro culture

ABSTRACT: Taro is a tropical tuberous vegetable that produces cormels of high nutritional and energetic value. In recent years, its cultivation has expanded, creating the need for more research. However, the experimental plot size interferes directly with the precision of the experiment.Literature describes several methods for establishing the optimum experimental plot size. The objective of the current research was to estimate the optimal experimental plot size for taro culture, utilizing the Modified Maximum Curvature Method. The field experiment was conducted in the vegetable garden of the Departamentode Fitotecnia of Universidade Federal de Viçosa, from September 2011 to June 2012, with Japanese taro. Twenty-two rows with 20 plants each were planted, at 1.0×0.3 m spacing, considering the 20 central rows with 18 plants each as useful area, totaling 360 plants. Each plant corresponded to a basic unit (BU). Once the possible clusters were made, 23 different plot sizes were formed. At harvest, the fresh mass characteristics of large, medium, and marketable cormels were evaluated. The optimum plot sizes were: 8.77 BU for marketable cormels; 14.75 BU for large cormels, and 13.37 BU for medium cormels. Among the plot sizes estimated in this study, the aim was to improve precision of experiments performed with taro, plots formed by 15 BU that corresponded to a 4.5 m2 area are recommended.摘要：芋头（taro）是一种热带块根类蔬菜，其结出的球茎具有极高的营养与能量价值。近年来其种植规模持续扩张，相关研究需求日益增长。然而，试验小区面积直接影响试验的精准度。现有文献已提出多种确定最优试验小区面积的方法。本研究旨在采用改进最大曲率法（Modified Maximum Curvature Method），估算芋头栽培的最优试验小区面积。本田间试验于2011年9月至2012年6月在维索萨联邦大学植物技术系（Departamentode Fitotecnia, Universidade Federal de Viçosa）的蔬菜试验园开展，供试材料为日本芋头。试验设置22行，每行20株，株行距为1.0×0.3 m；以中间20行、每行18株作为有效试验面积，总计360株供试植株。每株植株作为1个基本单元（basic unit, BU）。通过聚类组合后，共得到23种不同规格的试验小区面积。收获期测定了大、中、商品级球茎的鲜重性状。本研究得到的最优试验小区面积分别为：商品级球茎8.77个基本单元，大球茎14.75个基本单元，中球茎13.37个基本单元。综合本研究估算的各小区面积，为提升芋头试验的精准度，推荐采用由15个基本单元组成、对应面积为4.5 m²的试验小区。