ORCHARD SPRAYING ^EXPERIMENTS. 69 



We are furthermore of the opinion that when weather con- 

 ditions are right for the production of spray injury, no spray 

 material now known can be relied upon to counteract or avoid 

 it ; and this will be especially true when said conditions produce 

 injury on unsprayed fruit, as in the past season. Indeed it is 

 highly probable that the fruit injury obtained this year (if we 

 disregard the one kind that was undoubtedly caused by the 

 arsenical), was due to the application of a spray, irrespective of 

 its composition. In other words, under the unusual conditions 

 at spraying time, the addition of moisture may have increased 

 the degree of injury which the natural agents alone were capable 

 of inflicting. Future experiments may prove that satisfactory 

 fungicidal effects may be secured with greater dilutions at re- 

 duced risk of injury. 



Effectiveness of Lead Arsenate. 



This point has already been fully discussed. The results cor- 

 roborate those of experimenters previously mentioned regarding 

 the entire efficiency with lime-sulphur sprays, irrespective of the 

 chemical changes occurring when used together. The check 

 plots indicate that insects destructive to fruit were not especially 

 numerous. Codling moth, as previously noted, was perfectly 

 controlled. 



"Sulfocide" and Calyx Injury. 



The fact that calyx injury was found on neither check nor 

 bordeaux plots, together with the very severe injury of similar 

 nature on Plot 7 inclines us to the belief that this was the result 

 of a chemical change whereby the arsenic was set free in some 

 form capable of causing the results. The injuries already de- 

 scribed and more particularly those on Plot 7 bear a very strik- 

 ing resemblance to descriptions of a similar injury noted by Tay- 

 lor at the Missouri Fruit Station on apples sprayed in a rainy 

 season with bordeaux and Paris green. Between the second 

 and third applications "apples were noted in the Paris green plot 

 with blackened areas about their blossom ends. These black- 

 ened areas increased in size and became more conspicuous as 

 the apples grew. By picking time some of the areas now shriv- 

 eled had extended about the blossom end until it covered over a 

 third of the surface of the fruit. In some cases the burned tis- 



