Author
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Fisher, James |
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Submitted to: Conference of the North West Center for Small Fruit Research
Publication Type: Abstract Only Publication Acceptance Date: 11/1/2002 Publication Date: 12/1/2002 Citation: Fisher, J.R. 2002. Temperature effects on the life stages of populations of grape phylloxera (daktulosphaira vitifoliae) that are from different grape growing regions of the pacific nw.. Conference of the North West Center for Small Fruit Research. Interpretive Summary: Grape phylloxera is a recent pest threatening to destroy over 27,000 acres of self-rooted winegrapes in the Pacific Northwest region of the USA. Some vineyards have coexisted with this pest for over 15 years while others have been devastated in less than 5 years. We conducted this study to determine if life processes of populations of phylloxera from four different areas in nthe Pacific Northwest, USA, would show differences in survival, developmen and reproduction when reared at myriad of constant temperatures. Individual differences were observed among the four populations for development, survival and reproduction, but no trends were observed for any one population. However, the numbers for each parameter followed a general trend among temperatures. The results from this study and others support the hypothesis that localized differences in 'virulence' of infestations from vineyard to vineyard over an appellation may be a function, in part, of localized temperature differences caused by such factors as soil type, aspect, slope, pruning, ground cover, and plant spacing Technical Abstract: Grape phylloxera is a recent pest threatening to destroy over 25,000 acres of self-rooted winegrapes in the Pacific Northwest region of the USA. Some vineyards have coexisted with this pest for over 15 years while others have been devastated in less than 5 years. We conducted this study to determine if life processes of populations of phylloxera from four different areas in nthe Pacific Northwest, USA, would show differences in survival, developmen and reproduction when reared at myriad of constant temperatures (3 - 36 degrees C at 3 degree intervals). Individual differences were observed among the four populations for development, survival and reproduction, but no trends were observed for any one population. However, the numbers for each parameter followed a general trend among temperatures. The optimum temperature range for maximum response for all parameters was between 24 degrees C and 27 degrees C. Upper and lower temperature thresholds were, respectively, less than 6 degrees C and more than 33 degrees C. The results from this study and others support the hypothesis that localized differences in 'virulence' of infestations from vineyard to vineyard over an appellation may be a function, in part, of localized temperature differences caused by such factors as soil type, aspect, slope, pruning, ground cover, and plant spacing |
