68 FUXGI AXD rU^v-GICIDES 



ant just beneath the outer skin, riucl it pushes out 

 through the skin numerous ^•spore-sacs.** each contain- 

 ing a half dozen or more spores. These spores are sup- 

 posed to spread the disease to other peach leayes, but as 

 stated above, yery little is known of the life-history of 

 this fungus. 



Treatment. — Xo practical remedy for this disease 

 has yer been found. The removal and burning of dis- 

 eased leaves, vrhether on the tree or ground, is commonly 

 recommended ; and spraying the trtes early in spring, 

 before the leaves expand, with some of tiie fungicides, 

 has been suggested. The latter method is worthy of 

 trial. 



Literature. — The peach leaf-curl i? very frequently 

 mentioned in our horticultural literature, but few im- 

 portant articles concerning it have been published. The 

 best popular discussion that has come to my notice is in 

 Professor Lamson-Scribner's excellent little volume on 

 the Fungus Diseases of the Grape and Other Plants '' 

 (pp. 126-131). 



The Peach Yellows 



The peculiar affection of peach trees called the 

 ^\yellows,*' has been known to occur in America for at 

 least a century, and during that time it has ravaged 

 many of the fairest orchards of the country. Although 

 most commonly affecting peaches, it also occurs in nec- 

 tarines, almonds and apricots. 



Xo disease of fruits has proved so difficult to investi- 

 gate as this. Until very recently there were numberless 

 theories as to its cause, but the investigations of Dr. 

 Erwin P. Smith, to whom we are indebted for much of 

 the positive knowledge now possessed concerning it, 

 indicate that it is a germ disease, due, probably, to some 

 obscure bacterium-like organism. 



