Calculate daily infection values — calc

This function calculates the daily infection values for Cercospora beticola on sugar beet. Functions were adapted from Wolf and Verreet (2005) and Wolf et al (2001)

Usage

calc_DIV(date_time, Tm, RH, rain, dat)

Arguments

date_time: POSIX_ct, date time the weather recording was taken
Tm: numeric, temperature, in Celsius' at time increment in date_time
RH: numeric, relative humidity (%) at time increment in date_time
rain: numeric, volume of rain in millimetres recorded between time recordings
dat: data.frame, containing column names "times","temp","rh","rain" with each of the respective arguments for input. provided as a convenience

Value

data.table, with probability of infection for each day, between 0 and 1 Undertaken with two methods by Wolf and Verreet (2005)

References

Wolf, P. F. J., and J. A. Verreet. “Factors Affecting the Onset of Cercospora Leaf Spot Epidemics in Sugar Beet and Establishment of Disease-Monitoring Thresholds.” Phytopathology® 95, no. 3 (March 2005): 269–74. https://doi.org/10.1094/PHYTO-95-0269.

Wolf, P. F. J., M. Heindl, and J. A. Verreet. “Influence of Sugar Beet Leaf Mass Development on Predisposition of the Crop to Cercospora Beticola (Sacc.).” Journal of Plant Diseases and Protection 108, no. 6 (2001): 578–92.

Examples

date_t <- Sys.time() + seq(0, 179 * 60 * 10, (60 * 10))
Tm <- rnorm(180,20,10)
RH <- runif(180,min = 40,90)
rain <- rbinom(180,1,0.1) * runif(180,0.1,20)

DIV1 <- calc_DIV(
date_time = date_t,
Tm = Tm,
RH = RH,
rain = rain
)