The first symptoms of the disease appear at the end of springtime and increase through the crop cycle as the temperature increases, the presence of rain or high humidity. The symptoms the apple show are superficial necrotic spots. The affected fruits can’t be marketed anymore and the leaves may drop off prematurely.
According to agroberichtenbuitenland.nl, the Alternaria fungus causes problems in other apple producing areas of Europe and the world as well; Italy, the US and Australia are among these. The Alternaria also affects other plant species, especially some horticultural crops and other fruit trees, with notable damage to varieties of mandarins from the Spanish Levante.
