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Show CROWN GALL FOUND !N NURSERY STOCK Young Trees Are More Susceptible Suscepti-ble to Disease Than Older Ones Control Difficult. OBy J. M. MANN, New Mexico 'Agricultural 'Agricul-tural Experiment Station.) Crown gall is a bacterial disease which attacks such plants as the stone fruits, apples, pears, quinces, walnuts, chestnuts, poplars, willows, grapes, raspberries, blackberries, roses, tomato, toma-to, tobacco, beets, hops, carnations etc. The disease is caused by a specific bacterium and produces characteristic galls or knots on the roots of its host. The knot; or enlargement is often just at the crown of the roots, but also occurs on the smaller rnols or in some instances above the ground. The presence of the disease does not ordinarily kill the host rapidly but as the growth of the disease continues it gradually shuts off the wtilef supply of the plant attacked and death eventually follows. Young trees are much more seriously serious-ly injured by the disease than older ones. The greatest spread of the disease takes place in the shipping of infected nursery stock, but the organism causing caus-ing the disease can he scattered by Irrigation waler or tiny way that in-fecled in-fecled soil may be transferred from one field I o anol her. Mechanical injuries occurring at the time of cullivalioit make open wounds Ihrough which the organism attacks the host. The conl rol of the disease is very iliUleult. its Ibe removal of the gall does not insure the eradication of the trouble from the plant affected. Young trees in Ihe nursery are more susceplible to crown gall than older ones, and for this reason the disease can almost always be detected at the time of transplanliug. All diseased trees .should be rejecled. |