EXPERIMENT STATION REPORTS. 151 



than Paris greeu, its adhesive qualities make it far more valuable as 

 while a dashing raiu might wash the last trace of Paris green from the 

 foliage, it will have very little effect upon the spray of arsenate of lead 

 which has had time to dry on. The fact that arsenate of lead when 

 properly made can be used at considerable strength upon even the most 

 tender foliage, which would be serionslj^ injured when sprayed with 

 Paris green at greatly reduced strengths, makes it a much safer remedy 

 than Paris green or, in fact, any of the other arsenicals. The reports 

 that have been made from time to time by the station, upon the results 

 obtained with arsenate of lead as a substitute for Paris green upon 

 potatoes as well as fruit trees, have led to its coming into quite general 

 use for spraying purposes and, during the present year, tons will be re- 

 quired to supply the demand where ])Ounds answered a few years ago. 



For a number of years the manufacturers were not able to furnish 

 it in a form which could be readily mixed with water but they have 

 now so changed and improved their formulas that it is little if any more 

 work to prepare it than is required with Paris green. 



The results obtained Avith the lime-sulphur mixtures were not different 

 from those secured in previous years. Where the applications were 

 thoroughly nmde nearly as good results were secured with the com- 

 mercial mixtures as with th? home-made of the usual strength, although 

 the former did not seem as lasting in its effects, when used against the 

 San Jose scale. The price, of course, is considerably higher than that of 

 the home-made mixture but, when a small quantity only is desired and 

 especially if one does not have a kettle or outfit for cooking it, many will 

 prefer to purchase it already prepared. When a large amount of spray- 

 ing is to be done, at the present price of sulphur which is about two 

 dollars per one hundred pounds, the cost of making fifty gallons, using 

 the regular formula of fifteen pounds of sulphur and the same amount 

 of lime in fifty gallons, will be but little more than three-fourths of a 

 cent per gallon for material ; while at the low^est price quoted, the 

 commercial brands cannot be purchased for less than one and one-half 

 cents per gallon, diluted to contain the same amount of sulphur as in 

 the home-made mixture, so that the economy of the latter can be readily 

 seen. 



Many have objected to the use of the home-made mixtures because 

 when prepared after the usual formula they must be used at once and 

 many persons have trouble with their use through the clogging of the 

 nozzles. After considerable experimenting, Mr. Wilken was able to 

 make a concentrated solution Avhich closely resembled the commercial 

 brands and, as it had no sediment, it was ecjually free from objections 

 on account of clogging and could be kept as well, or even better, than 

 the more highly concentrated, commercial solutions. As was explained 

 in the report of the station, it contained only one-half the quantity of 

 lime used in the regular formula and, by a little extra boiling, could be 

 so concentrated that there would be 120 pounds of sulphur in fifty gal- 

 lons of the solution. 



Considerable attention was also given to the use of calcium bromide 

 and calcium sulphide as summer sprays for the control of the scab and 

 other fungous diseases of fruit trees but further experiments are de- 

 sired before positive conclusions can be reached. 



Cultural Experiments at South Haven. Next to spraying and the use 



