The response to anthracnose and walnut blight in 3 local and 5 recently introduced walnut varieties was studied in a field monitoring. A high level of leaf anthracnose incidence (100%) was reported for the Turkish varieties, in the Bulgarian varieties it was lower (60-80%), in Chandler (30%) and in Fernor – symptoms were completely absent. Regarding the same feature in relation to walnut blight, the American varieties were the most strongly affected – almost 100% of the leaves. As to the fruit – the disease incidence of anthracnose was almost 100% in all varieties with the exception of cv. Perustinski (55%). The affected fruit surface in the American varieties was, however, only 1%. The spread of walnut blight in the fruit was about 70% in the American varieties and it was not registered in the Bulgarian varieties. Recommendations for organic walnut production have been made.
Disease infestation on Bulgarian and introduced walnut varieties in organic plantations