Population Studies of the Potato Leafhopper, Empoasca Fabae (Harris), on Alfalfa, Medicago Sativa L.

Population Studies of the Potato Leafhopper, Empoasca Fabae (Harris), on Alfalfa, Medicago Sativa L. PDF Author: Donald Edward Simonet
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Languages : en
Pages : 206

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Population Studies of the Potato Leafhopper, Empoasca Fabae (Harris), on Alfalfa, Medicago Sativa L.

Population Studies of the Potato Leafhopper, Empoasca Fabae (Harris), on Alfalfa, Medicago Sativa L. PDF Author: Donald Edward Simonet
Publisher:
ISBN:
Category :
Languages : en
Pages : 206

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Economic Thresholds for Potato Leafhopper (Empoasca Fabae [Harris]) on Glandular-haired Varieties of Alfalfa)Medicago Sativa L.).

Economic Thresholds for Potato Leafhopper (Empoasca Fabae [Harris]) on Glandular-haired Varieties of Alfalfa)Medicago Sativa L.). PDF Author: Lindsay N. Gibson
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ISBN:
Category : Empoasca fabae
Languages : en
Pages : 172

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The Effects of Potato Leafhopper, Empoasca Fabae (Harris), (Homoptera: Cicadellidae) Density on Yield and Quality of Alfalfa, Medicago Sativa L.

The Effects of Potato Leafhopper, Empoasca Fabae (Harris), (Homoptera: Cicadellidae) Density on Yield and Quality of Alfalfa, Medicago Sativa L. PDF Author: Dhanraj Samaroo
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ISBN:
Category :
Languages : en
Pages : 170

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The Chemical Mechanism for Defense of Glandular-haired Alfalfa, Medicago Sativa L., Against the Potato Leafhopper, Empoasca Fabae (Harris)

The Chemical Mechanism for Defense of Glandular-haired Alfalfa, Medicago Sativa L., Against the Potato Leafhopper, Empoasca Fabae (Harris) PDF Author: Christopher M. Ranger
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ISBN:
Category : Alfalfa
Languages : en
Pages : 412

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Nonvolatile and volatile compounds from glandular-haired alfalfa genotype, Medicago sativa cv. 'G98A', were identified and bioassayed for their ability to affect preference behavior of the potato leafhopper, Empoasca fabae (Harris). Two-choice bioassays of nonvolatile trichome compounds determined leafhoppers preferred to settle on crude nonglandular trichome extracts from susceptible M. sativa cv. 'Ranger' over glandular trichome extracts from G98A. A nonpolar solvent, such as ethanol, was most effective in extracting biologically-active compounds. Trichome extracts from G98A also exhibited dose-dependent deterrency, such that an increase in extract concentration corresponded with increased leafhopper avoidance. Mass spectral analysis determined a homologous series of nonvolatile fatty acid amides C n H 2n+1 NO (n = 19-23) were major components of glandular trichome extracts from G98A, but were absent in trichome extracts from Ranger and the less resistant M. sativa cv. 'G98C'. When crude G98A trichome extracts were fractionated and bioassayed, a fraction of intermediate polarity exhibited strong, dose-dependent deterrency. However, by limiting contact with the deterrent fraction to only the leafhoppers stylets, it was determined that contact with nonstylet appendages was necessary for activity. Fatty acid amides were major components of the active fraction, and trace components were C12:0 through C18:0, and C18:1, free fatty acids. Activity slightly declined following removal of the free fatty acids. Purified fatty acid amides continued to deter leafhopper settling, and supplementation with authentic C 12:0-C18:0, and C18:1 free fatty acids resulted in increased activity. But, the free fatty acids alone were not deterrent. Mass spectral studies identified the major series of homologous fatty acid amides from G98A as N -(3-methylbutyl)amides of C14:0 through C18:0 fatty acids, and minor components as a homologous series of N-(methylpropyl)amides of C14:0 through C18:0 fatty acids. N -(3-methylbutyl)amide of linoleic acid (C18:2) was also present in trace amounts, as were C12:0 through C18:0, and C18:1, free fatty acids. A mixture of synthetic N -(3-methylbutyl)amides of C14:0-C18:0 did not exhibit dose-dependent deterrency, nor did a mixture of N -(methylpropyl)amides of C14:0-C18:0. In contrast, when tested singly, N -(3-methylbutyl)amide of linoleic acid (C18:2) exhibited dose-dependent settling deterrency. To assess the role of volatiles in leafhopper resistance, stem, leaf, and whole plant volatiles were collected using vacuum steam distillation and head-space analysis from G98A and Ranger: 1-Octen-3-ol, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate were the most predominant compounds in steam distillates from both plant selections, and (Z)-3-hexenyl acetate was a major component in head-space samples. No volatiles were unique to either G98A or Ranger, but (Z)-3-hexenyl acetate and 1-octen-3-ol were frequently collected in lower amounts from G98A compared to Ranger. In two-choice bioassays, potato leafhoppers oriented towards leaf steam distillates and head-space samples from Ranger over G98A. However, leafhoppers were not attracted to synthetic (Z)-3-hexenyl acetate or 1-octen-3-ol when tested singly against a solvent control.

Biological Studies on the Potato Leafhopper, Empoasca Fabae (Harris), as an Alfalfa Pest

Biological Studies on the Potato Leafhopper, Empoasca Fabae (Harris), as an Alfalfa Pest PDF Author: Costas Alexander Kouskolekas
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ISBN:
Category : Alfalfa
Languages : en
Pages : 236

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Quantification of Loss in Yield for Alfalfa (Medicago Sativa) Infested by the Potato Leafhopper (Empoasca Fabae)

Quantification of Loss in Yield for Alfalfa (Medicago Sativa) Infested by the Potato Leafhopper (Empoasca Fabae) PDF Author: Claudia Lee Womack
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ISBN:
Category : Alfalfa
Languages : en
Pages : 306

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Integrated Pest Management for the Potato Leafhopper (Empoasca Fabae) in Alfalfa

Integrated Pest Management for the Potato Leafhopper (Empoasca Fabae) in Alfalfa PDF Author:
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ISBN:
Category :
Languages : en
Pages : 193

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Alfalfa, Medicago sativa L., is one of the best quality dairy forages and as the principal forage legume in the U.S., is grown on roughly 10 million ha. Potato leafhopper, Empoasca fabae Harris, is its most economically damaging insect in the Midwest and northeast United States. Integrated pest management (IPM) programs for E. fabae in alfalfa consist of sampling and monitoring throughout the season, foliar insecticide treatments when economic thresholds are reached, host plant resistance and the cultural control of early harvest when economic thresholds are reached within a week of a planned harvest. The work presented here gives a thorough review of E. fabae ecology and biology, migration patterns and injury to host plants. A thorough review of available pest management strategies for E. fabae in alfalfa is discussed (chapter 1). An IPM system incorporating host plant resistance and orchardgrass intercroppings as a cultural control is studied with regards to affects on E. fabae abundance and alfalfa yield and forage quality (chapter 2). Alfalfa yield loss response to E. fabae feeding is assessed in order to validate the current economic injury level and economic threshold models for both susceptible and resistant alfalfa varieties (chapter 3). Lastly, soil fertility treatments are considered as a potential cultural control tactic for managing E. fabae in response to farmer observations (chapter 4).

Relationship of Potato Leafhopper, Empoasca Fabae (Harris) (Homoptera: Cicadellidae), Population to Hopperburn, Yield and Quality of Alfalfa in North Carolina

Relationship of Potato Leafhopper, Empoasca Fabae (Harris) (Homoptera: Cicadellidae), Population to Hopperburn, Yield and Quality of Alfalfa in North Carolina PDF Author: Hung-Wen Shen
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ISBN:
Category :
Languages : en
Pages : 226

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Simple-haired Pubescence of Alfalfa (Medicago Sativa Linneaus) as a Resistance Mechanism to the Potato Leafhopper (Empoasca Fabae Harris)

Simple-haired Pubescence of Alfalfa (Medicago Sativa Linneaus) as a Resistance Mechanism to the Potato Leafhopper (Empoasca Fabae Harris) PDF Author: Brian Gerard Christoffel
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ISBN:
Category : Alfalfa
Languages : en
Pages : 60

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Population Dynamics of the Potato Leafhopper, Empoasca Fabae, on Water-stressed Alfalfa

Population Dynamics of the Potato Leafhopper, Empoasca Fabae, on Water-stressed Alfalfa PDF Author: George Davis Hoffman
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ISBN:
Category :
Languages : en
Pages : 410

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