Uniformity trial size in estimates of plot size in restrict areas

Diogo Vanderlei Schwertner,Alberto Cargnelutti Filho,Alessandro Dal’Col Lúcio

doi:10.5935/1806-6690.20150043

Diogo Vanderlei Schwertner, Alberto Cargnelutti Filho + Show 1 more

Open Access

https://doi.org/10.5935/1806-6690.20150043

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Abstract

The aim of this study was to determine the uniformity trial size when estimating optimum plot size in order to evaluate fresh phytomass in lettuce plants and fruit weight in sweet peppers. Production data, collected in uniformity trial on lettuce in a plastic greenhouse in both summer and winter, lettuce in plastic tunnels in autumn and winter, and sweet pepper in a plastic greenhouse in the summer-autumn and spring-summer seasons, were used to plan different uniformity trial sizes in crop rows. In all the experiments, each plant was evaluated individually and considered as a basic experimental unit. For each size in a uniformity trial, 3,000 resamples, randomly taken with replacement, were used to estimate optimum plot size. Uniformity trial using 27 basic experimental units to evaluate the fresh phytomass of lettuce plants, and with 29 basic experimental units to assess fruit weight in sweet pepper, are sufficient to estimate optimum plot size, with an amplitude of the 95% confidence interval of less than or equal to two basic experimental units.

Highlights

The lettuce (Lactuca sativa) and sweet pepper (Capsicum annuum) are important crops for Brazilian horticulture
To this effect, designing experiments in tunnels and plastic greenhouses by determining plot size is essential for increasing experimental precision (STORCK et al, 2011) and maximising the information obtained from the available experimental area (CARGNELUTTI FILHO et al, 2011a; STORCK; BISOGNIN; OLIVEIRA, 2006)
The fresh phytomass (FP) of the winter lettuce evaluated in the greenhouse varied from 55 to 229 g plant-1, the average being 124.01 g plant-1 with a coefficient of variation (CV) of 31.88%

Summary

Introduction

The lettuce (Lactuca sativa) and sweet pepper (Capsicum annuum) are important crops for Brazilian horticulture. When cultivating vegetables in a protected environment, variability is introduced due to the proximity of the crop rows to the sides of the plastic tunnels (LORENTZ et al, 2005), to intensive management and damage to the crop (LÚCIO et al, 2008), to faults in the irrigation system (CARPES et al, 2008), to leaks and infiltration, to shading by the structure and to the heterogeneity of the soil (LÚCIO et al, 2011) To this effect, designing experiments in tunnels and plastic greenhouses by determining plot size is essential for increasing experimental precision (STORCK et al, 2011) and maximising the information obtained from the available experimental area (CARGNELUTTI FILHO et al, 2011a; STORCK; BISOGNIN; OLIVEIRA, 2006). Uniformity trial are carried out, known as blank trials (with no treatment), in which the whole experimental area is managed uniformly, and the individual production data of each plant is evaluated in order to learn the variability of the area and estimate plot size (STORCK et al, 2011)

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