136 Report of the Botanist of the 



SALISBURY experiment NO. I. 



This experiment was made by J. V. Salisbury & Sons, Phelps, 

 N. Y. Ten acres of potatoes were sprayed five times, on the follow- 

 ing dates : — July 24, August 8, 26, September i and 5. One row 

 1223 feet long was left unsprayed. The adjacent row on each side 

 of the unsprayed row was sprayed only once ; namely, in the first 

 spraying. (See diagram on page 138.) 



The spraying was done with a two-horse power sprayer purchased 

 of the Field Force Pump Co., Elmira, N. Y, The list price is $75.00. 

 (Plate XII.) At each passage six rows were sprayed with one 

 Vermorel nozzle per row. The bordeaux used was of the i-to-8 

 formula. Poison, white arsenic,^ was used with the bordeaux only 

 in the first spraying. Paris green was applied to the unsprayed row 

 once, in lime water. The field was about 40 rods from the water 

 supply which was pumped from a well by hand. One man pumped 

 the water and prepared the bordeaux while another did the spraying. 



The unsprayed rows^** began to show the effects of blight 

 (PhytopJithora) about September 5 and by September 9 there was 

 a marked contrast in appearance between the sprayed and unsprayed 

 rows. By September 12 the unsprayed rows could be recognized 

 at a long distance as a brown streak extending clear across the field. 

 At this time the field as a whole was making a fine appearance al- 

 though toward the south end there was a spot of perhaps one- fourth 

 acre in which blight had already become thoroughly established. All 



" Arsenite-of-lime paste was prepared from the white arsenic as follows: 

 10 pounds of white arsenic and 15 pounds of salsoda (common washing 

 soda) were boiled together in 8 gallons of water until dissolved. The result- 

 ing solution was used to slake 20 pounds of quick lime, water being added 

 to make a moist paste. Enough of the paste to contain about one pound 

 of the arsenic was used with 50 gallons of bordeaux. 



"Rows 4, 5 and 6 of the diagram on page 138. Strictly speaking only- 

 Row 5 was an unsprayed row but in this discussion Rows 4 and 6 are also 

 classed as unsprayed rows. The single spraying they received was too early 

 to do them much good. 



