Cultivation Populations of American chestnut were devastated by the mid-20th century by chestnut blight, Cryphonectria parasitica, syn. Endothia parasitica; Chinese chestnut and Japanese chestnut are relatively immune. Devastation was such that American chestnuts are no longer commercially viable. The European chestnut is also susceptible and has been attacked by blight since 1938 and production is consequently decreasing.