May 6, 1918 Canker of Poplars and Willows 339 



How serious this disease may be when it attacks poplar cuttings in 

 the propagating beds is shown by the following data^ from the Fort Hays 

 Experiment Station nurseries situated at Hays, Kans. In 191 5 two 

 different plots containing about 10,000 Carolina poplar cuttings' each 

 were planted. On one of these plots situated on level creek-bottom 

 land about 95 per cent of the cuttings started to grow. "When the larger 

 ones were about 10 inches tall, they began to turn yellow, quit growing, 

 and gradually died until there was less than i per cent alive at the close 

 of the season, and these were only i to 2 feet high. The second block 

 of cuttings was located about 20 rods from the other block. These 

 cuttings started nearly as well as those in block i, but gradually died 

 in the same manner until only about 40 per cent were alive at the end of 

 the season. Most of the plants in this second bed grew about 3 feet 

 high, a few were 4 to 5 feet tall, and many were only i to 2 feet in height. 

 Specimens of the diseased cuttings from these two plots examined by 

 the writer had the typical red spore horns of Cytospora chrysosperma 

 which had entered at the exposed cut ends of the cuttings and had 

 finally killed them. 



The remedy for this loss in cuttings is to change the system of propaga- 

 tion for those species of poplar which are susceptible to the disease. The 

 writer has seen the following method of propagating the Carolina and 

 Lombardy poplars used with good success in the dry regions of New 

 Mexico. The small branches or twigs which have been selected for 

 propagating purposes, instead of being cut into 6- or 8-inch pieces, are 

 placed entire in the bottom of a trench 2 to 4 inches deep. They are 

 then entirely covered with sand, kept damp by frequent v/atering, but 

 well drained; and in due season the dormant buds along the twigs 

 grow and send up shoots, while an abundance of roots develop along 

 the buried twig. Propagating stock thus handled does not present any 

 exposed surface to be infected by the fungus. 



DISTRIBUTION OF THE FUNGUS 



Cytospora chrysosperma is rather widely distributed in certain sections 

 of the United States, especially in the Southwestern States. It ranges 

 from Texas and Kansas northward to Montana and westward to Cali- 

 fornia. It has been found in nine States — Arizona, Colorado, Kansas, 

 Montana, Nevada, New Mexico, North Dakota, South Dakota, and Texas; 

 and also in Mexico. The fungus is widely distributed in Europe, having 

 been reported from Germany, Austria, Switzerland, Italy, France, and 

 Sv/eden. 



' The above data were obtained through the kindness of Mr. J. W. Preston, formerly in charge of the 

 Fort Hays Experiment Station. 



