Blackspot Canker. 97 



should be made. For these applications 6-4-50 Bordeaux mixture is 

 advised. Of the two applications, the first should immediately follow 

 the gathering of the fruit. This is necessary in order that the work 

 may be done before rainy weather sets in. The second application 

 should be made two to three weeks later, depending upon weather con- 

 ditions — if heavy rains occur the spraying should be done within two 

 weeks, otherwise the work may be delayed one to two weeks later. All 

 spraying done to control anthracnose must be done thoroughly in order 

 to get the desired results. 



Owing to the fact that even following the application of double 

 strength Bordeaux (12-8-50) mixture, as is recommended for use in 

 Western Washington, much of the active principles in the spray are 

 rendered worthless by being removed from the tree early during the 

 season by heavy showers or during long rainy periods. In order to meet 

 this Situation the writer prepared a mixture known as Bordeaux- 

 petroleum emulsion, spraying the trees twice before the heavy rains 

 began. Although only four trees, all badly infested with the disease, 

 as shown by the presence of a large number of cankers from which spores 

 were being discharged, three of which were sprayed with the mixture, 

 good results in the control of the disease were secured as well as dis- 

 covering that the petroleum contained in the mixture had a toxic effect, 

 the leaves being much darker and healthier than those on the unsprayed 

 tree or those which had only received coatings of Bordeaux mixture and 

 standing in the same part of the orchard. 



SIg. 4 



