State-of-the-art and Problems of Walnut Propagation Methods

Abstract

At present budding and grafting are the most widely used approaches in the production of grafted walnut trees. Poor callus formation in walnut makes it difficult to propagate. Walnut propagation by cuttings is a method difficult to be realized. The presence of high concentration of phenolic compounds in its tissue and their oxidation, is the major reason of using micropropagation as a suitable method. The most commonly used technique is patch budding. Other used methods are bench grafting and hot callus. In the last years hot callus as a technique has been successfully used for propagation of walnut cultivars, but the height of the trees is not enough at the end of the season. A new walnut propagation method is called epicotyl grafting. All the methods of walnut propagation are discussed in the present paper.