336 Plums and Plum Culture 



Pacific coast region. The sunburn is described by 

 Tourney as occurring in Arizona. Speaking of what 

 he calls curl-leaf, Hedrick says: "Beginning in mid- 

 summer, the leaves begin to curl conduplicately with- 

 out withering, but shriveling somewhat. As the sea- 

 son advances the leaves become a yellowish brown and 

 many of them drop. It affects practically all the Italian 

 Prune trees, there being but rarely a tree that escapes. 

 As far as I can learn, all other varieties are exempt. 

 In some orchards the trees are almost wholly stripped 

 of their foliage." 



Although definite experiments in the treatment of 

 this disease, or these diseases, do not seem to have 

 been made, the practical treatment of them is very 

 strongly hinted at in the foregoing paragraphs. Treat- 

 ment must be preventive rather than remedial. 

 Measures likely to prevent the appearance of sunburn 

 or curl-leaf are proper cultivation, keeping the soil in 

 good mechanical texture, aeration of the soil, proper 

 drainage, proper irrigation, and the preservation of 

 vigorous, healthy foliage by timely spraying. 



Single-tree disease. — This malady I have observed 

 in nearly every orchard I ever visited. With unimpor- 

 tant exceptions it is always caused by the hired man. 

 It seems to be quite impossible to prevent his ravages. 

 There are times when it seems to be his chief aim in 

 life to drive the plow or cultivator in such a manner as 

 to insure the effective skinning of the trees by the 

 single-tree. 



There seems to be no satisfactory preventive of 

 this trouble, unless the owner is able to plow and culti- 

 vate his own orchard with a well-trained team. Short 

 single-trees, with leather sheaths at the ends of the 

 tugs, will reduce the damage to some extent. Har- 

 nesses which do away with hames and single-tree are 

 highly recommended, and are doubtless very useful. 



