Walnut breeding is carried out according to three main criterias: productivity,
product quality of fruits, and tolerance. Productivity is the defining characteristic,
and all the high-yielding forms are to be identified and counted according to it.
High-yielding form of low crop commodity quality of breeding are to be applied for
Nuciferous breeds are in most cases formed of little value forms and their
productivity is low. This is the reason why some of the most important problems of
walnut development are improvement of the quality of existing trees, creation of
new highly productive plantations and their further rational use.
For many years scientists have conducted breeding works trying to create best
varieties of walnut. Our experience of such work still suggests that the most
valuable varieties of nuts are the ones that have the fruits weighing around 10 -16
grams, with a yield of 15-40 kilos per a tree.
Such varieties are considered to be high-quality marketable products, in contrast to
large-fruited varieties with thin shells.
It is also necessary to improve the breed’s frost and adverse environmental
conditions tolerance, pest and disease resistance. This might be achieved if
selecting varieties with late flowering periods, early ripening, and a short growing