THE IKRIGATION AGE. 



825 



SPRAYING FOR PEACH FRUIT SPOT. 



A. B. CORDLBY AND C. C. GATE. 



The disease which is known by Oregon peach growers 

 most commonly as "peach fruit spot" and also as "fungus," 

 "shot-hole fungus," "peach spot" and "brown spot," has been 

 in evidence for many years, during the past few of which it 

 has occasionally caused no little loss. In some instances the 

 crop has been so spotted that it could not be disposed of on 

 the open market, and many tons of otherwise luscious fruit 

 have been forced to the canneries Or evaporators. Still more 

 unfortunate is the fact that often a portion of the infested 

 fruit is worthless and is left to decay on the trees and in the 

 orchard, thereby harboring and spreading the disease so that 

 year by year it may secure a firmer and surer hold upon each 

 succeeding crop. 



Under date of August 2, 1906, M. A. L. Kitchen, man- 

 ager of the Ashland Fruit and Produce Association, for- 

 warded to us a box of badly infested Hales Early peaches 

 with the accompanying statement : "Many of our peaches this 

 year are affected with a disease which causes spots on them 

 much resembling scale." Later so many similar reports were 

 received from most of the peach growing sections of the state 

 that we decided to undertake a study of the disease and of 

 the best methods of controlling it. 



The spraying experiments which were begun in the spring 

 of 1907, were conducted the first season in co-operation with 

 Mr. Benton Bowers, who contributed the use of his orchard 

 near Ashland. During the two succeeding seasons the work 

 has been continued in co-operation with Mr. Albert Joy, who 

 purchased the orchard of Mr. Bowers. To both Mr. Bowers 

 and Mr. Joy we desire to express our hearty appreciation for 

 the many courtesies extended. 



The orchard in which the work was done consists of about 



as had been produced having been "spotted" and of but little 

 value. 



The object of the experiments was to compare the effi- 

 ciency of Bordeaux mixture and lime-sulphur in controlling 

 the disease; and to determine the number of applications 

 necessary and the best times at which they should be applied. 

 During the first season's work the lime-sulphur was used only 

 for the first application before the buds started in spring, but 

 during all the later experiments it has been tested as well for 

 the summer applications. 



Fig. II. The So-called "Culls" from Sprayed Trees Could Have Been 

 Marketed as Second Grade Fruit. 



Work in 1907. 



The first application in 190 T was made between February 

 27th and March 4th, just as the first buds were swelling. A 



Fig. I. Much of the Fruit from the Unsprayed Trees Was Practically Worthless. 



twelve acres of fifteen-year-old trees, mostly Muir, with some 

 Albertas and Crawfords'. It is well located, with a gentle 

 slope to the northeast, and the soil which is deep and of the 

 decomposed granite type is considered excellent for peaches. 

 Nevertheless the trees had generally been neglected, very little, 

 if any, spraying had ever been done and we were told that 

 the orchard had never produced a profitable crop such fruit 



block of about two acres was sprayed with Bordeaux mixture 

 and the remainder with Phoenix lime-sulphur solution. Later 

 the two acre block, which comprised thirteen rows across the 

 north end of the orchard, was subdivided into plots for the 

 purpose of determining the relative efficiency of several differ- 

 ent methods of treatment. 



In the following table, which is intended to show the treat- 



