Bulletin Volume 183-189 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...A grafted tree of this character can not develop into a good tree unless it can form roots on the scion portion above the union. It is inadvisable on general principles to plant any trees affected by a contagious disease like crown-gall, and particularly so with varieties that do not root well from the scion. Trees of the following varieties are more likely to overcome a mild attack of crown-gall, as they are better able to root from the scion: Ben Davis, Wolf River, Northern Spy, Grimes, Gano, Northwestern Greening, Missouri, Wealthy, Walbridge, Fameuse, and Salome. The following statement made by Wickson (77) fully meets the views of the writer and applies to hairy-root as well as to crown-gall: If the diseased growth is so extensive during the early period of the life of the tree as to stunt the development of the root system, no favorable results can be expected during the later period of development of such a tree. It is fortunate that nursery trees are generally dug and sold at a period when the stunting effect, of these diseases is most marked. The same statement might be made of many poorly rooted trees which have not formed a perfect union between scion and root piece in the root graft and as a result have a defective root system, irrespective of these diseases. These constitute a considerable loss to the nurseryman where poorly fitted root grafts are used. These statements apply to both hard and soft crown-gall and to all of the forms of hairy-root found in the nursery. The results of the investigation indicate very clearly that apple trees are able to resist the effects of these forms of disease in the orchard, and their importance has been greatly overrated. It must not be understood, however, that trees diseased with even the milder forms of cr...