72 



FUXGI AXD FUXGICJDES 



entirely diseased in the course of two seasons, or at 

 most^ three. 



^*The limbs first attacked are badly diseased the 

 second year^ their entire growth^ shoots and foliage^ 

 being much dwarfed and of a sickly green^ tinged with 

 yellow or reddish-brown. In course of two or three sea- 

 sons the entire growth of the tree assumes this appear- 

 ance, and is then a sufficient warrant for the common 

 name, such trees especially, when massed in orchards, 

 being distinguishable at some distance by their yellow 

 or reddish-brown appearance, which is in marked con- 

 trast with the beautiful dark green of healthy foliage. 



" Trees not infrequently die outright the second 

 year of attack, but ordinarily they languish for a num- 

 ber of years, dying gradually from the extremities down- 

 ward. Often such trees are barren after the first year, 

 or they may bear another crop of premature peaches, 

 which are, however^ of small size and very inferior 

 flayor.^^ 



An orchard ruined by yellows is represented in 

 Plate YII, while in Fig. 37 is shown a tuft of diseased 

 twigs. 



Treatment. — Xo remedy for this disease is known. 

 The only successful treatment yet found is that of 

 promptly digging out and burning all affected trees. 

 In several States this is made compulsory by s^Dccial 

 laws, and in Michigan^ at least, it has proven qnite a 

 satisfactory method of stamping out the disease. 



Literature. — A very elaborate report upon the 

 peach yellows^ prepared by Dr. Erwin F. Smith, was 

 published in 1888, as Bulletin Jfo. 9 of the Botanical 

 Division of the United States Department of Agricul- 

 ture. A short summary of the same results was also 

 published in the Department Eeport for the same year 

 (pp. 393-398). Since then Dr. Smith has published 

 various reports of ^^rogress in the 23ub]ications of the 



