Sampling procedures for spittlebug adults in pastures of Brachiaria decumbens.
A sampling study of spittlebug adults in pastures of Brachiaria decumbens was conduced to find an appropriate number of sweep-net sweeps/sample. Considering the relative variation (SE/X) X 100, and the total number of sweeps in the sampling, 10 sweeps/sample were found to be better than 5,20 our 40. The number of samples required for a particular level of relative variation at population densities>16 spittlebug adults/10 sweeps remained the same, whereas at densities<16, the number increased inversely. A regression model to convert relative estimates obtained by sweep-net method to the absolute estimate was presented. Considering the degree of precision and the time spent in sampling, the sweep-net method was superior to cage method. The distribution pattern of numbers of spittlebug adults in samples of 10 sweep-net sweeps, generally fitted the poisson series. A sequential plan presented here would reduce the sampling time over the conventional (fixed sample numbers) sampling.
Main Authors: | , , |
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Other Authors: | |
Format: | Artigo de periódico biblioteca |
Language: | English eng |
Published: |
1997-02-28
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Subjects: | Spittlebugs, Pasture, Amostragem, Brachiaria Decumbens, Cigarrinha das Pastagens, Deois Flavopicta, Pastagem, Zulia Entreriana, Cercopidae, sampling, |
Online Access: | http://www.alice.cnptia.embrapa.br/alice/handle/doc/319774 |
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Summary: | A sampling study of spittlebug adults in pastures of Brachiaria decumbens was conduced to find an appropriate number of sweep-net sweeps/sample. Considering the relative variation (SE/X) X 100, and the total number of sweeps in the sampling, 10 sweeps/sample were found to be better than 5,20 our 40. The number of samples required for a particular level of relative variation at population densities>16 spittlebug adults/10 sweeps remained the same, whereas at densities<16, the number increased inversely. A regression model to convert relative estimates obtained by sweep-net method to the absolute estimate was presented. Considering the degree of precision and the time spent in sampling, the sweep-net method was superior to cage method. The distribution pattern of numbers of spittlebug adults in samples of 10 sweep-net sweeps, generally fitted the poisson series. A sequential plan presented here would reduce the sampling time over the conventional (fixed sample numbers) sampling. |
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