Figure 2.

The dependence of four epidemiological parameters on the within-plant virus titre. r(x) is the probability that a cutting taken from an infected crop plant does not carry the virus (is reversed), p(x) is the probability that an infected cutting is correctly detected as infected, ω(x) is the roguing rate and β(x) is the transmission rate. x_half is the virus titre at which half of the infected cuttings are correctly detected as infected.