Diseases effects on sustainability and evolution of chestnut ecosystem in Italy

The two most destructive diseases of chestnut (Castanea sativa Miller) are chestnut blight and ink diseases which are spreading in Italy and through other European countries. These constrain factors play an important role in the evolution of chestnut stands and orchards, affecting their management. Predominance of hypovirulence was observed in the majority of European chestnut stands and orchards. Healing cankers arising from the action of hypovirulent strains of Cryphonectria parasitica were detected in the stands investigated. Factors involved in the natural spread and predominance of the hypovirulent strains are cited. New lines of the parasite spread, but the damages produced are undetectable for the effect of the natural mixed inoculum, which could buffer any variations in the genome lines. Management of chestnut stands and orchards and the spread of hypovirulent strains enhances the natural biological control of the disease. Ink disease attacks produce severe damage in chestnut stands and orchards and influence their evolution Treatments with integrated organic fertilisers have produced the re-growth of symptomatic chestnut trees.