Research at the Salinas USDA office has helped follow the origins of the disease that caused the Great Famine in Ireland, all the way back to its roots in Mexico.
Though the Irish strain has since died out, the disease still persists in the Salinas Valley in tomato crops.
Its still a problem today, said Frank Martin, a Salinas native and plant pathologist at the USDA. It hasnt gone away.
Potato late blight and tomato blight are caused by the same organism: a fungus-like, single-celled microbe called Phytophthera infestans. The organism thrives in wet environments and produces long-lived spores that travel in the wind. It causes potatoes to turn black, wilts leaves and infects the stems.
Europe remained free from potato blight for three centuries after the Spanish introduced potatoes in the 1400s. Then, in 1845, the organism showed up suddenly in Belgium. It spread rapidly through mainland Europe and then to the United Kingdom and Ireland. The resulting Great Famine was especially devastating in Ireland because its population was so dependent on potatoes. One million people died and another million emigrated.