106 The Spraying of Plants. 



the use of the combination rapidly gained favor. One of the 

 conclusions reached was that " London purple (Paris green and 

 white arsenic have not yet been tried) can be used at least eight 

 or ten times as strong without injury to foliage if applied in 

 common Bordeaux mixture instead of water." Later experi- 

 ments have shown that Paris green can be applied in the same 

 manner with greater safety than when pure water is used. 



Although the smuts of grain are not best treated by spraying, 

 still these diseases are sufficiently connected with the subject in 

 hand to allow the mention of some work done by Kellerman 

 and Swingle. 1 In 1889 the work was mainly verifying the 

 methods proposed by Professor Jensen, of Copenhagen, Den- 

 mark, for the treatment of the various grain smuts. The 

 following year fifty-one methods for treating the stinking smut 

 of wheat were tried. " Of all the treatments tested, the Jensen, 

 or hot-water method, is probably the best for general use, 

 although in our experiments it did not prevent all the smut" 

 (see Part II. under OATS). 



Halsted published a report in 1889 which proved to be the 

 beginning of an important series. 2 This first publication con- 

 tained notes on diseases of the potato, grape, cranberry, cucum- 

 ber, sweet potato, and lilac, those of the cranberry having 

 already been mentioned in Bulletin 64 of the station. The 

 reader is referred to later reports by the same investigator for 

 the descriptions and methods of treatment of a great many dis- 

 eases of plants cultivated out of doors, and also of those grown 

 under glass. The reports are especially rich in the accounts of 

 diseases affecting greenhouse plants, and those commonly grown 

 by florists. 



During 1890, Maynard continued his work on the combina- 

 tions of insecticides and fungicides. 3 He used the ammoniacal 

 carbonate of copper together with Paris green. The foliage 

 was in all cases seriously injured, and the fungicide appeared to 

 lose its- value when used in this manner. Later experiments 

 have generally agreed with this result, and such a combi- 

 nation has not been used in common practice. Kerosene had 



1 Kansas Agric. Exp. Sta. 1889, Oct. Bull. 8, and 1890, Aug. Bull. 12. 



2 Ann. Sept. IT. J. Agric. Exp. Sta. 1889, 221-239. 



Mass. Hatch Agric. Exp. Sta. 1891, Jan. Bull. 11, 18. 



