384 Bulletin 74. 



mans. It occurs upon a variety of plants, as raspberries, rose, 

 Marianna plum, pear, apricot and almond ; and Wickson and 

 Woodworth report it upon the grape in California. It is said to 

 be very serious upon the Pacific coast. The galls vary in size 

 from that of a pea to twice as large as a man's fist. German 

 writers consider that the disease is due to mechanical injuries of 

 the roots, but this hypothesis is wholly incompatible with the 

 appearance and the spread of the trouble. No investigator has 

 yet been able to discover any insect, fungus or germ to be uniform- 

 ly associated wi'h the galls. The man in whose orchard I found 

 the galls in Niagara county is convinced that his trees became 

 diseased by growing them in a nursery where infested raspberries 

 were previously grown. The disease is prevalent in our owu 

 raspberry' plantations at Cornell, and we are able to keep it in 

 check only by pulling up and burning all suspected plants. If 

 berries are affected by this trouble, I should advise destroying 

 the plantation and setting another upon non-infested ground. 

 This disease must not be confounded with the root-knot of the 

 peach and other plants in warm climates and in greenhouses, 

 which is the work of a nematode worm.* 



This root-gall has been studied by Professor Woodworth of 

 California, t who giv^es the following advice : "i. In the orchard 

 the knots should be carefully removed and burned as soon as 

 found, and an antiseptic application made to the tree where the 

 knot has been removed. We would recommed Bordeaux mixture 

 for this purpose. Trees so treated should be examined from time 

 to time for at least a 5'ear, and should the knot reappear, it would 

 be best to remove and destroy the whole tree. When a tree is 

 removed, it would be well to delay resetting for a year or two, or 

 to reset with a tree of unsusceptible kind. 2. When setting an 

 orchard, reject all stock affected by the knot. I would prefer to 

 have stock from a nursery known to be entirely free from it. 3. 

 In the nursery, the greatest care should be taken to destroy, by 



* An illustration and account of the nematode upon winter tomatoes, will 

 be found in our Bulletin 43. 



tBull. 99, Cal. Exp. Sta. (Dec. i, 1892). See also E. F. Smith, Jour. My- 

 cology, vii. 93 ; Bull. Torr. Bot. Club, xx. 363. 



