Jozef Májsky 
A death knell of the chestnut tree ?

20 years ago already experts pointed out to the fact that Czechoslovakia is the only country in Europe where nuts of the chestnut tree Castanea sativa get ripe because the dangerous fungal disease Cryphonectria (Endothia) parasitica has not attacked the said territory. In 1983 to 1990 58 trees of Castanea sativa in various localities were proclaimed a protected nature reserve. After 1989 original owners and gourmets started to show interest in the said trees and, mainly diseases, but also knocking the nuts off contributed to a rapid worsening of the health state of the trees. Fungal diseases e.g. C. parasitica, Valsa (Cytospora) intermedia and Marssonia castagnei caused their drying up and dieback. Against the most dangerous fungus C. parasitica a method of a biological control has been developed in France lying in the application of hypovirulent tribes of this fungus. This method will be used for the rescue of Castanea sativa in Slovakia.