Publications by authors named "Ann E MacGuidwin"

Models were developed to quantify the impact of to the early season growth and yield of soybean in field and greenhouse environments and to estimate yield loss because of . in Wisconsin. There was a negative linear relationship between initial nematode population densities () and shoot and total plant weight at V2 and yield, pod number, seed number, and seed mass at harvest in the field.

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induce necrotic lesions, the hallmark symptom for the genus, soon after infection. The objective of our study was to characterize and quantify gender differences in lesion development. Independent experiments were conducted for three hosts; pea ( L.

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is a common and important agricultural pest in Wisconsin, a USA state with a diverse agriculture. We compared populations from around the state to each other and to data published for populations around the world to gain insight on the variability of features important for identification of this cosmopolitan species. Thirteen isolates from samples collected in soybean fields in ten Wisconsin counties were established in monoxenic cultures.

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In a search for an entomopathogenic nematode to control cranberry insect pests, three Oscheius populations (Rhabditidae) were recovered through the Galleria-bait method from one sample taken in a wild cranberry marsh in Jackson County, Wisconsin, USA. Morphological studies with light microscopy and scanning electron microscopy, as well as molecular analyses of the near-full-length small subunit rDNA gene, D2/D3 expansion segments of the large subunit rDNA gene, internal transcribed spacer, and mitochondrial cytochrome oxidase subunit 1 (CoxI) genes revealed this as Oscheius onirici, a species recently described from a karst cave soil of central Italy. The species belongs to the dolichura-group and is characterized by its DNA sequences; hermaphroditic reproduction; and males not found.

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The lesion nematode Pratylenchus penetrans is a common pest of corn in the north-central United States. There are relatively few studies documenting the impact of Pratylenchus spp. on grain yield even though they are recognized as pests of corn and the target of commercial seed treatments.

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For this report, we examined the toxic effects of three plant-derived isothiocyanate compounds on second-stage juveniles (J2) of Heterodera glycines. We found significant differences among compounds in the concentration required to affect nematodes, according to mortality and behavioral measurements. The concentrations required to affect behavior were significantly lower than those required for mortality.

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Background: Soybean cyst nematode (Heterodera glycines, SCN) is the most economically damaging pathogen of soybean (Glycine max) in the U.S. The Rhg1 locus is repeatedly observed as the quantitative trait locus with the greatest impact on SCN resistance.

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Field experiments were conducted for three consecutive years to study the effects of low populations of Verticillium dahliae and Pratylenchus penetrans on leaf gas exchange of Russet Burbank potato. Treatments were P. penetrans, V.

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