Persistent Link:
http://hdl.handle.net/10150/211111
Title:
Whitefly Growth Regulators: A Field Sampling Protocal for Nymphs
Author:
Diehl, J. W.; Naranjo, S. E.; Ellsworth, P. C.
Issue Date:
Mar-1997
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Cotton: A College of Agriculture Report
Abstract:
We developed a sampling protocol for nymphs of the sweetpotato whitefly for timing the application of insect growth regulators. These plans require counting the number of large, visible nymphs within a 3.88 cm² leaf disk on the fifth main stem node leaf down from the terminal. Use of insect growth regulators for whitefly control is recommended when whitefly densities from 30 plants average 0.5 - 1.0 large nymphs per disk and 3 - 5 adults per leaf. We evaluated these sampling and decision- making plans within a large -scale field experiment. Precision was adequate for densities of 1.0 large nymph per leaf and greater, but sample sizes greater than 30 are needed for lower densities. The ability of samplers to detect and categorize nymphal instars and sampler-to-sampler variation in this ability were significant sources of variation. A binomial (presence/absence) sampling plan may diminish sampler-sampler variation while increasing efficiency and accuracy of decision- making.
Keywords:
Agriculture -- Arizona; Cotton -- Arizona; Cotton -- Insect investigations
Series/Report no.:
370108; Series P-108

Full metadata record

DC FieldValue Language
dc.titleWhitefly Growth Regulators: A Field Sampling Protocal for Nymphs-
dc.contributor.authorDiehl, J. W.en_US
dc.contributor.authorNaranjo, S. E.en_US
dc.contributor.authorEllsworth, P. C.en_US
dc.date.issued1997-03-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalCotton: A College of Agriculture Reporten_US
dc.description.abstractWe developed a sampling protocol for nymphs of the sweetpotato whitefly for timing the application of insect growth regulators. These plans require counting the number of large, visible nymphs within a 3.88 cm² leaf disk on the fifth main stem node leaf down from the terminal. Use of insect growth regulators for whitefly control is recommended when whitefly densities from 30 plants average 0.5 - 1.0 large nymphs per disk and 3 - 5 adults per leaf. We evaluated these sampling and decision- making plans within a large -scale field experiment. Precision was adequate for densities of 1.0 large nymph per leaf and greater, but sample sizes greater than 30 are needed for lower densities. The ability of samplers to detect and categorize nymphal instars and sampler-to-sampler variation in this ability were significant sources of variation. A binomial (presence/absence) sampling plan may diminish sampler-sampler variation while increasing efficiency and accuracy of decision- making.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectCotton -- Arizonaen_US
dc.subjectCotton -- Insect investigationsen_US
dc.identifier.urihttp://hdl.handle.net/10150/211111-
dc.relation.ispartofseries370108en_US
dc.relation.ispartofseriesSeries P-108en_US
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