Relationship between sampling intensity and precision for estimating damage to maize caused by rodents
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Date
2007
Journal Title
Journal ISSN
Volume Title
Publisher
Blackwell Publishing and IOZ/CAS
Abstract
In this study we aimed to determine the relationship between sampling intensity and precision for estimating rodent
damage. We used the systematic row sampling technique to provide data to achieve precision and accuracy in
estimations of rodent damage in maize fields at the planting and seedling stages. The actual rodent damage to maize
in 15 fields, each 0.5 ha in size, in Morogoro, Tanzania, was established at the seedling stage. These data were used
to simulate the sampling intensities that would provide precision and accuracy. The variations between estimates
were plotted against the sampling intervals. The results of this study show that the relationship between average
standardized variances and sampling intervals is linear. The heterogeneous distribution of damage in some plots
caused variations in the accuracy of the estimates between plots, but a sampling interval of five rows consistently
produced estimates with a variance of less than 10%. We provide a standard curve that will allow a decision to be
made on the sampling intensity as a function of required precision using the systematic row sampling technique in
maize fields.
Description
Keywords
Sampling interval, Simulation, Standard curve, Systematic row sampling, Rodents