Seed Borne Late Blight of Potato

Fig. 8. Effect of timing of seed piece treatment on emergence of seed pieces 49 days after inoculation with Phytophthora infestans in (A) Oregon and (B) Washington. Seed pieces of potato cultivar Shepody were inoculated with sporangia of P. infestans genotype US-8 in Oregon and US-11 in Washington and then treated with thiophanate methyl + mancozeb (Tops MZ) immediately, 1.5 or 3 days after inoculation.



Image from Plant Health Progress article:
Seed Borne Late Blight of Potato