DUSTING AND SPRAYING EXPERIMENTS OF 1918 AND 1919. 27 



Applications. Four applications were made as follows: 



1st. Just before blossoms opened. 



2nd. Just after the petals had fallen. 



3rd. Two weeks after second. 



4th. About one month before fruit was ripe. 



The 90-10 mixture was used for the first three applications and sul- 

 phur only for the fourth. 



RESULTS 



The dusting materials caused no injury at any time on the Japanese 

 varieties. The trees of the native and European varieties were also free 

 from injury. 



EXPERIMENTS IN 1919 

 A COMPARATIVE TEST OF ARSENICALS ON PLUMS 



An orchard of plums on the College grounds at East Lansing, which 

 contains blocks of Lombard, Shropshire Damson, and Moore's Arctic, 

 was used for a comparative test of several arsenates. There were five 

 rows of trees in this experiment and each row constituted a plot and 

 contained trees of each of the varieties. A different arsenate was used 

 on ea-ch row. Check trees of each variety were left unsprayed. 



Materials. The arsenates used are listed below: 



1st. Corona dry lead arsenate, 1*4 Ibs. in 50 gal. 



2nd. Corona calcium arsenate, 1 Ib. in 50 gal. (lime added). 



3rd. Dow magnesium arsenate, 114 Ibs. in 50 gal. 



4th. NuRexfonn lead arsenate, 1% Ibs. in 50 gal. 



5th. Rex calcium arsenate, 1 Ib. in 50 gal. (lime added). 



They were all used in combination with lime-sulphur diluted at the 

 rate of 1 to 40. 



Applications. Three applications were made as follows: 

 1st. Just before the blossoms opened. 

 2nd. Soon after the petals had fallen. 

 3rd. Two weeks after second. 



All spraying was done with a spray gun. 



RESULTS. 



There was considerable foliage injury in all plots especially after the 

 third application, but most of this was lime-sulphur injury as the 

 temperature was quite high at that time. There was some injury which 

 probably was arsenical injury but it was not severe and was not con- 

 fined to any one plot. The foliage of the unsprayed trees was in ex- 

 cellent condition. Lombard seemed more susceptible to injury by spray- 

 ing materials than the other varieties. 



DUSTING AND SPRAYING CHERRIES AND PLUMS AT GRAND RAPIDS 



On the farm of Mr. J. C. Maynarc}, near Grand Rapids, comparative 

 tests were made with sulphur dust, lime-sulphur solution and bordeaux 



