FORMULATION OF A MODEL TO RELATE NEMATODE POPULATIONS WITH EXPOSURE TIMES TO A RANGE OF TEMPERATURES

To assess the efficacy of a method of control against a target pathogen, information is required on the relationship among pathogen mortality as affected by rate x exposure time.
To predict the performance of soil solarization against nematodes a model linking nematode survival x temperature x exposure time is desirable.
Considering that log pathogen survival x exposure time at a constant temperature relationship is linear and can be represented by the equation y = a – bx and that Brown and Melling (1971) found that during the heat sterilization the variation of bacteria population can be represented by the equation log P_i – log P_o = – Δtk/2.30258 the model P_t = P_o 10^{-Δt/(q + mt)} can be used to calculate the nematode population after a heat treatment.
In this equation P_t = the nematode population after Δt exposure time in hours; P_o = nematode population before the heat treatment; Δt = is the exposure time, above t_t (defined as the threshold exposure time x temperature below which the organisms are not killed), (t_l – t_o); m and q are the angular coefficient and the know term, respectively of the straight line that represents the function = f(T); T is the temperature in °C at which the nematode population was exposed.

International Symposium on Chemical and Non-Chemical Soil and Substrate Disinfectation

N. Sasanelli, N. Greco

Control, solarization, mathematical model, temperature, exposure time

https://doi.org/10.17660/ActaHortic.2000.532.15