SPECIAL REPORT FOR YEAR I912. 45 



The apple spraying experiments of the past season were the 

 third of the series. A brief resume of the results of the two 

 preceding years was included in this report for iQii. Weather 

 conditions for 191 1 were such that very little scab developed, 

 therefore the experiments for that year were duplicated for 

 1912 with much more satisfactory results. On account of the 

 more severe outbreak of scab these results regarding certain 

 features of the experiments were quite clear cut and conclusive. 



The most important lesson to be drawn from the work of the 

 present year is with regard to the value of the appHcation of 

 the spray made first at the time the flower buds are showing 

 pink. It is not recommended to omit the later sprayings, but 

 where they were made last season and the first spraying omitted 

 the work was probably done at a loss. Where all three appli- 

 cations were made almost perfect results were obtained. In 

 other words last season the appHcation of the spray made just 

 as the blossoms zvere showing pink zvas several times more 

 effective than the other tzvo taken together. 



Lime-sulphur applied at the proper time effectually controlled 

 scab and was very free from leaf injun,- and produced only a 

 small amount of russeted fruit. Bordeaux mixture, under like 

 conditions controlled scab better than did lime-sulphur but upon 

 the very susceptible Ben Davis produced so much russeting of 

 the fruit that this more than off-set the beneficial effects. 



Four pounds of arsenate of lead to fifty gallons of water 

 plainly was of considerable fungicidal value. In fact the results 

 were fully as good as on adjoining plots where two pounds 

 of lead arsenate to fifty gallons of lime-sulphur were used. The 

 heavy application of lead arsenate did result in considerable leaf 

 injury, however. Arsenate of zinc and dry arsenate of lead 

 were used with entire success with regards effect on foliage 

 and fruit, and controlled insect pests, including codling moth, 

 as effectually as did the ordinary lead arsenate paste. 



POTATO SCAB. 



The work on potato scab is being continued. Recently 

 specimens of a new form of scab called "powder}^ scab" have 

 been received from an adjoining County of Canada. This like 

 the blackleg and potato canker or wart disease were probably 



