/epirice

Simulation Modelling of Rice Crop Diseases Using a Susceptible-Infectious-Removed (SEIR) Model

Primary LanguageRGNU General Public License v3.0GPL-3.0

epirice: Simulation Modelling of Rice Crop Diseases Using a Susceptible-Exposed-Infectious-Removed (SEIR) Model

tic codecov Project Status: Active – The project has reached a stable, usable state and is being actively developed.

A fork of the R cropsim package designed to make using the EPIRICE model for rice diseases easier to use. This version provides easy to use functions to fetch weather data from NASA POWER, via the nasapower package and predict disease severity of five rice diseases using a generic SEIR model (Zadoks 1971) function, SEIR().

The original manuscript, Savary et al. (2012), which details the model and results of its use to model global epidemics of rice diseases was published in Crop Protection detailing global unmanaged disease risk of bacterial blight, brown spot, leaf blast, sheath blight and tungro, which are included in this package.

Quick start

You can easily simulate any of the five diseases for rice grown anywhere in the world from 1983 to near current given internal functionality. Alternatively, you can supply your own weather data for any time period as long as it fits the model’s requirements.

epirice is not yet on CRAN. You can install it this way.

if (!require("remotes"))
  install.packages("remotes")
remotes::install_github("adamshsparks/epirice"
)

Get weather data

First you need to provide weather data for the model. epirice provides the get_wth() function to do this. Using it you can fetch weather data for any place in the world from 1983 to near present by providing the longitude and latitude and dates.

library(epirice)

# Fetch weather for year 2000 wet season at the IRRI Zeigler Experiment Station
 wth <- get_wth(
   lonlat = c(121.25562, 14.6774),
   dates = c("2000-06-30", "2000-12-31")
 )

wth
##        YYYYMMDD DOY    TM    TN    TX  TDEW    RH  RAIN   LAT   LON
##   1: 2000-06-30 182 25.94 29.19 22.97 23.63 87.22 11.36 14.68 121.3
##   2: 2000-07-01 183 25.34 28.31 23.65 23.76 91.07 24.87 14.68 121.3
##   3: 2000-07-02 184 25.99 29.91 23.28 23.40 85.71 17.63 14.68 121.3
##   4: 2000-07-03 185 25.35 27.23 24.00 24.32 94.01 33.52 14.68 121.3
##   5: 2000-07-04 186 25.58 27.35 24.20 24.42 93.28 16.21 14.68 121.3
##  ---                                                               
## 181: 2000-12-27 362 24.27 26.20 22.65 23.06 92.93 26.32 14.68 121.3
## 182: 2000-12-28 363 24.39 26.87 23.16 23.08 92.33  6.67 14.68 121.3
## 183: 2000-12-29 364 24.39 27.46 22.58 22.94 91.57  7.19 14.68 121.3
## 184: 2000-12-30 365 24.96 28.50 22.60 22.67 87.13  2.97 14.68 121.3
## 185: 2000-12-31 366 24.22 28.49 21.26 21.95 87.21  3.04 14.68 121.3

Modelling bacterial blight disease severity

Once you have the weather data, run the model for any of the five rice diseases by providing the emergence or crop establishment date for transplanted rice.

bb <- predict_bacterial_blight(wth, emergence = "2000-07-01")

bb
##      simday      dates  sites latent infectious removed senesced rateinf
##   1:      0 2000-06-30  100.0   0.00        0.0     0.0    0.000    0.00
##   2:      1 2000-07-01  108.7   0.00        0.0     0.0    1.000    0.00
##   3:      2 2000-07-02  118.1   0.00        0.0     0.0    2.087    0.00
##   4:      3 2000-07-03  128.3   0.00        0.0     0.0    3.268    0.00
##   5:      4 2000-07-04  139.3   0.00        0.0     0.0    4.551    0.00
##  ---                                                                    
## 117:    116 2000-10-24 1454.8  27.84      901.1   296.2 2195.459    0.00
## 118:    117 2000-10-25 1463.9  27.84      901.1   296.2 2210.007   25.41
## 119:    118 2000-10-26 1405.3  25.41      887.1   338.1 2266.527   22.32
## 120:    119 2000-10-27 1354.0  47.73      848.3   376.9 2319.390   19.22
## 121:    120 2000-10-28 1309.4  66.95      812.2   413.0 2369.048   16.73
##      rtransfer rgrowth rsenesced diseased severity   lat   lon
##   1:      0.00   9.688     1.000        0     0.00 14.68 121.3
##   2:      0.00  10.500     1.087        0     0.00 14.68 121.3
##   3:      0.00  11.374     1.181        0     0.00 14.68 121.3
##   4:      0.00  12.315     1.283        0     0.00 14.68 121.3
##   5:      0.00  13.326     1.393        0     0.00 14.68 121.3
##  ---                                                          
## 117:      0.00  23.642    14.548     1225    38.97 14.68 121.3
## 118:     27.84  23.374    56.521     1225    38.82 14.68 121.3
## 119:      0.00  23.895    52.863     1251    39.37 14.68 121.3
## 120:      0.00  24.249    49.657     1273    39.82 14.68 121.3
## 121:      0.00  24.489    54.158     1292    40.17 14.68 121.3

Once you have the results you can visualise them.

library(ggplot2)

ggplot(data = bb,
       aes(x = dates,
           y = severity)) +
  labs(y = "Severity",
       x = "Date") +
  geom_line() +
  geom_point() +
  labs(title = "Bacterial blight disease progress over time",
       caption = "Weather data acknowledgement:\nThese data were obtained from the NASA Langley Research Center POWER Project\nfunded through the NASA Earth Science Directorate Applied Science Program.") +
  theme_light()

Meta

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

References

Serge Savary, Andrew Nelson, Laetitia Willocquet, Ireneo Pangga and Jorrel Aunario. Modeling and mapping potential epidemics of rice diseases globally. Crop Protection, Volume 34, 2012, Pages 6-17, ISSN 0261-2194 DOI: 10.1016/j.cropro.2011.11.009.

Jan C. Zadoks. Systems Analysis and the Dynamics of Epidemics. Laboratory of Phytopathology, Agricultural University, Wageningen, The Netherlands; Phytopathology 61:600. DOI: 10.1094/Phyto-61-600.