TABLE 1
Disease Diffusion Parameters
| Parameter | Description | Value | Unit |
|---|---|---|---|
| α | Within-column H to Eu transition rate | 4.2 | Month– 1 |
| β | Across-column H to Eu transition rate | 0.014 | Month– 1 |
| γ | Distance-dependence, power-law parameter | 3 | Unitless |
| c | Probability of transition from Exposed-undetectable (Eu) to Exposed-detectable (Ed)  | ||
| m1 | Minimum of undetectability period | 4 | Month |
| m2 | Maximum of undetectability period | 18 | Month |
| m3 | Mode of virus undetectability period | 12 | Month |
| d | Probability of transition from Exposed-detectable (Ed) to Infective (Im)  | ||
| Ly | Latency period for young vines | 24 | Month |
| Lm | Latency period for mature vines | 48 | Month |
| Lo | Latency period for old vines | 72 | Month |
| f | Probability of transition from Infective-moderate (Im) to Infective-high (Ih) f =Pr(si,j,t + 1 = Ih | si,j,t = Im) = 1 – e –1/Inf | ||
| Inf | Period between state Im and state Ih. | 36 | Month |
| τmax | Period from planting until fruit bearing | 36 | Month |
Sources: The value of parameter value γ is obtained from Cabaleiro and Segura (1997). All other parameters are from Atallah et al. (2015), where values of parameters α and β are obtained from model calibration using data from Charles et al. (2009) with validation using data from Cabaleiro and Segura (2006) and Cabaleiro et al. (2008).