Abstract Cassava mosaic disease (CMD) is transmitted by infectious whiteflies and infected planting material. We investigate a deliberately reduced two-state host–vector model, derive its reproduction threshold and equilibria, and formulate robust transmission suppression under interval uncertainty. Positive invariance and global disease-free stability for R₀ ≤ 1 are established analytically. Independently recomputed synthetic experiments examine subcritical, critical and supercritical trajectories, equilibrium branches and nine constrained control-allocation scenarios. For the illustrative baseline, R₀ = 2 and the endemic equilibrium is (0.5625, 0.4286). Worst-case control allocations enforce R꜀ ≤ 0.95 under prescribed upper transmission bounds; optimal allocations depend strongly on relative effort weights. These results concern a stylised model rather than calibrated field dynamics. Infected-cutting introduction, heterogeneous whitefly ecology and empirical validation remain outside its scope. Stochastic dynamics and Koopman forecasting are identified as future research rather than completed results