TY - JOUR
T1 - Modeling the Survival of Two Soilborne Pathogens under Dry Structural Solarization
AU - Shlevin, Eli
AU - Saguy, I. Sam
AU - Mahrer, Yitzhak
AU - Katan, Jaacov
PY - 2003/10/1
Y1 - 2003/10/1
N2 - Structural (space) solarization of a closed, empty greenhouse for sanitation involves dry heating to 60°C and higher and low relative humidity (RH), under a fluctuating temperature and RH regime. Survival of inocula of Fusarium oxysporum f. sp. radicis-lycopersici and Sclerotium rolfsii during structural solarization was studied for 4 years (total of 12 experiments) in an attempt to develop a dynamic model for expressing the thermal inactivation of the pathogens. After 20 days of exposure, the populations of F. oxysporum f. sp. radicis-lycopersici and S. rolfsii were reduced by 69 to 95% and by 47.5 to 100%, respectively. The Weibull distribution model was applied to describe pathogen survival. The Weibull rate parameter, b, was found to follow an exponential (for F. oxysporum f. sp. radicis-lycopersici) and the Fermi (for S. rolfsii) functions at constant temperatures. To improve the applicability of the model, fluctuating conditions of both temperature and RH were utilized. The Weibull distribution derivative, expressed as a function of temperature and moisture, was numerically integrated to estimate survival of inocula exposed to structural solarization. Deviations between experimental and calculated values derived from the model were quite small and the coefficient of determination (R2) values ranged from 0.83 to 0.99 in 9 of 12 experiments, indicating that ambient RH data should be considered. Structural solarization for sanitation could be a viable component in integrated pest management programs.
AB - Structural (space) solarization of a closed, empty greenhouse for sanitation involves dry heating to 60°C and higher and low relative humidity (RH), under a fluctuating temperature and RH regime. Survival of inocula of Fusarium oxysporum f. sp. radicis-lycopersici and Sclerotium rolfsii during structural solarization was studied for 4 years (total of 12 experiments) in an attempt to develop a dynamic model for expressing the thermal inactivation of the pathogens. After 20 days of exposure, the populations of F. oxysporum f. sp. radicis-lycopersici and S. rolfsii were reduced by 69 to 95% and by 47.5 to 100%, respectively. The Weibull distribution model was applied to describe pathogen survival. The Weibull rate parameter, b, was found to follow an exponential (for F. oxysporum f. sp. radicis-lycopersici) and the Fermi (for S. rolfsii) functions at constant temperatures. To improve the applicability of the model, fluctuating conditions of both temperature and RH were utilized. The Weibull distribution derivative, expressed as a function of temperature and moisture, was numerically integrated to estimate survival of inocula exposed to structural solarization. Deviations between experimental and calculated values derived from the model were quite small and the coefficient of determination (R2) values ranged from 0.83 to 0.99 in 9 of 12 experiments, indicating that ambient RH data should be considered. Structural solarization for sanitation could be a viable component in integrated pest management programs.
KW - Fluctuating climatic conditions
KW - Greenhouse sanitation
KW - Inoculum eradication
UR - http://www.scopus.com/inward/record.url?scp=0141813615&partnerID=8YFLogxK
U2 - 10.1094/PHYTO.2003.93.10.1247
DO - 10.1094/PHYTO.2003.93.10.1247
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AN - SCOPUS:0141813615
SN - 0031-949X
VL - 93
SP - 1247
EP - 1257
JO - Phytopathology
JF - Phytopathology
IS - 10
ER -