Author
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Pinkerton, John |
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BRISTOW, PETE - WASHINGTON STATE UNIV |
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Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 9/9/2005 Publication Date: 11/1/2005 Citation: Pinkerton, J.N., Bristow, P. 2005. Soil solarization: a component in managing raspberry root rot. Methyl Bromide Alternatives and Emissions Research Conference Proceedings. 114. Interpretive Summary: Soil solarization is a process that employs solar radiation to heat soil under a transparent plastic film to temperatures that are detrimental to soilborne pathogens. The objective of this research was to evaluate solarization alone, fungicides alone (Ridomil Gold and Alliette), and solarization combined with fungicides to control raspberry root rot caused by Phytophthora fragariae pv. rubi. Field experiments were established in Pierce and Whatcom counties, Washington. Plots were solarized from late July through late September 2003 and planted with root rot susceptible cultivars Malahat and Qualicum in May 2004. In late fall 2004, there were more canes per hill and canes lengths and weights were greater in solarized plots compared to the nonsolarized plots. The fungicides-solarization combination produced no better plant growth than solarization alone. In June 2005, stands were more vigorous in solarized plots and those plots receiving fungicide applications than in the nonsolarized plots. Laboratory studies were conducted to determine the lethal temperature dose for P. fragariae pv.rubi. Colony growth ceased at 29º C and exposure to 29º for 192 hours was lethal. Over 200 cumulative hours of temperatures above 29º were recorded at 30 cm soil depth in solarized plots at both locations. Data suggest that soil solarization is a viable management option for controlling root rot caused by P. fragariae pv. rubi and climatic conditions in all raspberry production areas in the Pacific Northwest are suitable for effective solarization Technical Abstract: Soil solarization is a process that employs solar radiation to heat soil under a transparent plastic film to temperatures that are detrimental to soilborne pathogens. The objective of this research was to evaluate solarization alone, fungicides alone (Ridomil Gold and Alliette), and solarization combined with fungicides to control raspberry root rot caused by Phytophthora fragariae pv. rubi. Field experiments were established in Pierce and Whatcom counties, Washington. Plots were solarized from late July through late September 2003 and planted with root rot susceptible cultivars Malahat and Qualicum in May 2004. In late fall 2004, there were more canes per hill and canes lengths and weights were greater in solarized plots compared to the nonsolarized plots. The fungicides-solarization combination produced no better plant growth than solarization alone. In June 2005, stands were more vigorous in solarized plots and those plots receiving fungicide applications than in the nonsolarized plots. Laboratory studies were conducted to determine the lethal temperature dose for P. fragariae pv.rubi. Colony growth ceased at 29º C and exposure to 29º for 192 hours was lethal. Over 200 cumulative hours of temperatures above 29º were recorded at 30 cm soil depth in solarized plots at both locations. Data suggest that soil solarization is a viable management option for controlling root rot caused by P. fragariae pv. rubi and climatic conditions in all raspberry production areas in the Pacific Northwest are suitable for effective solarization. |
