VINEYARD SPRAYING AGAINST ROSE-CHAFER. 



59 



made to control the rose-chafer by the same means and more or less 

 experimentation along this line has taken place. 



Cage experiments with arsenical poisons against the beetles seemed 

 to indicate that a. large amount of arsenic was necessary to kill them. 

 At a date previous to the general use of arsenate of lead heavy appli- 

 cations of arsenicals in some instances resulted in serious injury to 

 the foliage of grapevines. This injury was caused by heavy appli- 

 cations of London purple, Paris green, and arsenite of lime, which 

 are some of the more caustic forms of arsenicals. With the placing 

 upon the market of reliable and properly-made brands of arsenate of 

 lead, however, an arsenical is now available which can be used in 

 large amounts without injury to the foliage of the vine. Hence there 

 is now practically no danger of injury by arsenical burning, and in 

 addition to this the arsenate of lead has a much greater adhesive 

 quality than the other arsenicals previously mentioned, thus render- 

 ing its poisoning effect of longer duration. 



In the field experiments against this pest during the past season, 

 arsenate of lead was used in combination with Bordeaux mixture and 

 in most instances at a strength of 5 pounds of arsenate of lead to 50 

 gallons of the spray liquid. 



Experiments were undertaken in three vineyards covering 4 acres 

 of grapevines on the farm of Page Bros., at North East, Pa., 4 acres 

 on a vineyard owned by the Prospect Park Fruit Farms Co., and 3 

 acres on the farm of Mr. C. F. Hirt. Since this pest breeds outside 

 the vineyards it is well-nigh impossible to predict, beforehand, either 

 the extent of the infestation or the portions of the vineyard most 

 likely to be infested, although the latter condition may be deter- 

 mined to some extent by close observations of local conditions over 

 several seasons, and since it is desirable that the first feeding of 

 the invading beetles shall be upon poisoned blossom-buds and foliage 

 this necessitates the application of the first spray on or about the time 

 the first beetles appear. Thus at the time of selecting a vineyard for 

 experimental work the extent of infestation likely to occur during the 

 season is quite problematical. The only thing to be done is to select 

 vineyards reputed to suffer annually from invasions by this pest. In 

 two of the experiments, those in the vineyard of Page Bros, and of 

 Mr. C. F. Hirt, the first application was made before the grape 

 blossom-buds had opened and before the beetles appeared. 



The plat arrangement in the Page vineyard was as follows : 



Rows. 



Bordeaux mixture. 



Arsenate 

 of lead. 



Molasses. 



Water. 



8 



Lime, 3 pounds 



Pounds. 

 5 

 5 



1 gallon 



1 gallon 



50 gallons. 



12 



Lime, 3 pounds; copper sulphate, 3 pounds 



Check 



50 gallons. 



4 





16 



Lime, 3 pounds; copper sulphate, 3 pounds 



5 



None 



50 gallons. 







