3 



The results, as given in tables I and II, and in the text, are expressed in per- 

 centage of scabby apples present in the check and in each sprayed or dusted plot. 

 In interpreting the results of any sprajdng or dusting experiments, the percentage 

 of infection in the check is of primary importance. If this is low, the data are 

 correspondingly of less value, since it cannot be said that the fungicidal treatment 

 was put to a real test. The percentage of infection on the unsprayed trees in the 

 Sabine orchard where some of the spraying experiments were conducted was so 

 low that the results in that orchard are not considered in this report. 



Methods and Materials Used. 



The trees used for these experiments were of the Mcintosh variety. Each orchard 

 was divided in such a way that the check plot was as nearly as possible hke the 

 treated plots in every way except fungicidal treatment received. The check plots 

 received no treatment for scab control, but did receive a calyx application with 

 insecticides only. All check plots were surrounded by or contiguous to the treated 

 plots. In dividing an orchard for a dusting experiment, it is difficult to so locate 

 the check plot that it will not receive some dust as the dust drifts through the 

 orchard. If it were possible to prevent this entirely, the percentage of scabby 

 fruits on the dust checks would probably be larger. 



The f oUoAAing treatments were tested or compared : 



1. Dry Ume-sulfur 3-50 for the pink, calyx and one later application. 



2. Drj'^ hme-sulfur 3-50 with calcium caseinate added for the pink, calyx, and 

 one later apphcation. 



3. Dry lime-sulfur 2-50 for the pink, calyx and one later application. 



4. Dry lime-sulfur 4-50 for the pink, calyx and one later apphcation. 



5. Dry hme-sulfur 3-50 for the prepink, pink, calyx and one later apphcation. 



6. Bordeaux mixture 3-10-50 for the prepink and pink apphcations followed 

 by hquid hme-sulfur 1-50 for the calyx and one later apphcation. 



7. Bordeaux mixture 3-10-50 for the pink apphcation followed by liquid hme- 

 sulfur 1-50 for the calyx and one later application. 



8. Atomic Sulphur for the pink, calyx and one later application. 



9. Liquid hme-sulfur for the pink, calyx and one later apphcation. 



10. Bordeaux mixture 3-10-50 for the pink application foUowed by dry lime- 

 suhur 4-50 for the calyx, and one later apphcation. 



11. Liquid hme-sulfur with lime added for the pink, calyx and one later apph- 

 cation. 



12. Copper dust for the prepink and pink apphcations followed by sulfur dust 

 for the calyx and two later apphcations. 



13. Sulfur dust for the prepink, pink, calyx and two later applications. 



14. Sulfur dust with calcium caseinate added for the prepink, pink, calyx and 

 two later applications. 



In one orchard, the dusting schedule began with the pink instead of the prepink 

 apphcation. 



An examination of Tables I and II will show which treatment each of the thirty- 

 five plots received, including the fungicide and its dilution used at each apphcation, 

 together with the date of each application. 



Rates of Application. 



About four gallons of spray per tree per application were used for trees twelve 

 to fifteen years old. About one and one-half pounds of dust per tree of this size 

 were used at each application. 



Liquid lime-sulfur was used at the rate of one gallon in fifty gallons of water. 

 Dry lime-sulfur was used at the rate of two, three or four pounds in fifty gaUons; 

 this is expressed in abbreviated form in the te.xt as dry lime-sulfur 2-50, 3-50, etc. 

 It was not found necessary to add water to this material before placing it in the 

 spray tank; in fact, to do so resulted in increased lumpiness. A more satisfactory 

 method is to sift this material into the nearly filled spray tank with the agitator 

 running. 



Calcium caseinate spreader (which is sold under various trade names, such as 

 Kayso, Spracein, etc.) was used at the rate of 1 pound in 100 gaUons, or it was 



