SPRAYING WHKKK SEVERAL DISEASES ARE PRESENT. 179 



WINTKK ULIGIIT OF TlIK I'KACH AND OTHER SPOT AND SHOT-HOLE DISEASES, SUCH AS 



Phi/llosticta circumscism berk., Cercospora circnmscissa sacc, etc. 



In the Northwest, on the I'tieitie coa.st, there are several diseases of 

 the peach not generally known throughout the East, and also several 

 other diseases conmion to both sections of the country. These troul)les 

 are generally known as leaf spot or shot-hole diseases. One very 

 widely distri))iited disease is that produced })y CercoNjjora ciraumsclxsa 

 Sacc, but one of the most trou])lesonie diseases of this class that 

 occurs in California and Oregon, is induced by a fungus not yet fully 

 studied, which infests the tender and bearing ])ranches and appears to 

 begin its vegetative activity some time prior to the ])looming of the 

 tree in the spring. On account of the hal)it of the fungus to grow in 

 the dormant or semidormant branches of the tree, the disease is termed 

 by the writer the whiter Might of the peach. It is one of those dis- 

 eases which destroys the most valuable young growth of the tree, i. e., 

 the shoots which are low and suited to the production of the finest 

 fruit. This disease, in common with another quite prevalent on the 

 Pacific coast and which is prol)ably induced hy a Conjnetun^ does 

 most damage in the more humid localities. Both do their more serious 

 work so early, as is also true of p(>a<li leaf curl, that summer spraying 

 would have but little eti'ect toward their control. Both induce o-mu- 

 mosis of the affected branches, as is true of the action of manv fungi, 

 and is a well-marked result of the presence of Coryneitm hyerlnck'd 

 Ond. Winter blight has already been successfully treated with the 

 winter sprays, and it is believed that such spraying is sufficient for its 

 control, provided the work be done thoroughly and repeated each year. 



There is no doubt that the winter treatment of the peach for curl is 

 properly and essentially the first step for the control of any of the 

 above-mentioned diseases. Too much can not be said in favor of this 

 treatment, which disinfects the trees before vegetative growth begins. 

 The striking thoroughness of such disinfection work may be seen 

 from the records given below. 



SOOTY MOLD OP THE PEACH. 



When the Department spraying experiments began in the Rio 

 Bonito orchard, there w^as everywhere present on the trunks, inner 

 limbs, and older bark of the experiment trees a fungous "smut," or 

 "sooty mold,'? giving the bark a black appearance when closely 

 examined. Of the 58 rows included in this block, 35 were sprayed, 

 as before stated, prior to March 10, and 23 left unsprayed for com- 

 parison. On August 10, 5 months after the spraying was completed, 

 all but 4 rows were examined for the presence of sooty mold, with the 

 following result: 



Sprayed rows showing no sooty mold August 10: Nos. 1, 3, 6, 7, 10, 

 12, 13, 15, 16, 18, 19, 21, 22, 25, 27^ 28, 33, 35, 36, 38, 39, 41, 45, 47, 48,.50, 

 51, 54, 56, and 57 — total, 30 rows. 



