95 



ll has not yet completed its work. During- midwinter 

 anotlK r crop of spores is produced and scattered. These 

 gain h)dguieut in the cracks and crevices of the bark 

 and in the forks of twigs and at the growing |K>iiits, 

 ready to germinate and penetrate the tissues of the bark 

 as spring opens up. 



Treaimoit. — The most effective method of controlling 

 this disease is to cut out all the knots as soon as they 

 appear and burn th(Mn. This work should be supple- 

 mented by s]3raying with Bordeaux ( four p<^)unds of cop- 

 per sulphate and live ]K)unds of fresh lime to fifty gallons 

 of water). Four applications are necessary, two for the 

 winter crop of spores and two for the summer croj). The 

 first shculd be made about two weeks before the buds be- 

 gin to ()]); n, and the s(M-ond immediately before they 

 o]«'!!. The thir.l ai)i>lication shimld be made about the 

 middle of May at the time the summer crop of spores is 

 produced, followed in about two weeks with the fourth. 



All wild cherry and plum trees should be carefully 

 watche<l, as they are frecjuently badly attacked, and 

 affected i>arts nuist be cut away and burned. 



THE CROWN GALL. ( Derulrophagiis gJobosus.) 



This is a dark, rough, abruptly protruding tumor 

 growing most commonlv from the crown of the tree, and 

 varying in size from that of a pea to that of the fist, or 

 larger — the latter usually on old and long infested trees. 

 A badly affected tree is likely to show signs of starva- 

 tion, its growth ceasing and its foliage having a sickly 

 yellow look. Young trees often perish from this disease, 

 which is certainly contagious in some forms and perhaps 

 in all, and even large orchard trees may die and finally 

 break off at the base of the trunk. 



Although much the most common abo>e tlu^ crown, just 

 below the surface of the ground, this gall frecpiently 

 grows on the larger roots, and is sometimes seen exposed 

 on the trunk. Appearing at first as a simple lump or 

 tubercle, it may so extend its growth as to girdle the 

 trunk with its large wart-like excresences. Young galls 

 while still fresh have at first the color of the roots from 

 Avhich they grow, but later darken from the accumula- 

 tion of dead bark on their surfaces. They are at first, 

 while very small, softer than the healthy tissue of the 

 root, but harden with age, and their inner structure be- 



