Field Susceptibility to Fusicoccum Canker of Almond Cultivars

The disease called "fusicoccum canker" or "fusicoccum", caused by the fungus Phomopsis amygdali Del. (synonym Fusicoccum amygdali Del.), is an important pathogen in almond-growing areas of Spain and other Mediterranean countries. The fungus is propagated mainly by water, so orchards located near the ocean, rivers, or dams, with high relative humidity, are particularly prone to this disease. In almond plots in Mas de Bover, located near the seashore, "fusicoccum canker" is a common and serious problem. In 2008, which had heavy rainfall during May and June (265.6 mm), very favorable conditions for disease development occurred, but cultivars and selections included in IRTA's almond germplasm collection were affected in very different ways. An assessment was carried out of disease incidence, classifying 70 cultivars from Australia, France, Greece, Italy, Portugal, Spain, Tunisia, Ukraine, and the U. S. A. and 36 selections from France, Greece, Iran, Israel, Italy, and Spain on their sensitivity or tolerance to this fungus. All cultivars and selections were placed in five classes according to their infection degrees: very tolerant (11 cultivars and 8 selections), tolerant (16 cultivars and 7 selections), medium (11 cultivars and 8 selections), susceptible (15 cultivars and 4 selections), and very susceptible (17 cultivars and 9 selections).