240 Report of the Botanical Department or the 



THE PLATTSBURGH EXPERIMENT. 



Conducted bj Pardj Brotliers, Plattsburgh, ]^. Y. Thirteen 

 acres of potatoes were sprayed all over three times and about four- 

 sevenths of the field (including the test rovi^s) were sprayed a 

 fourth time. A strip of six unsprayed rows constituted the check. 

 Bordeaux mixture of the 4-5-50 formula was used. It was made 

 with water pumped by hand from a well about one-fourth mile 

 from the potato field. The sprayer used was a two-horse, six-row 

 "Aroostook " carrying one nozzle per row. Before the experiment 

 was commenced the entire field was treated twice with a strong 

 solution of arsenite of soda in water containing as much lime as 

 could be forced through the nozzles. This was done in an attempt 

 to control flea beetles and leaf hoppers. As might have been ex- 

 pected, the plants were considerably injured, but this does not 

 affect the experiment since the test rows were all treated alike. 

 The plants were somewhat affected by tip bum, but there was no 

 blight. 



The items of expense were as follows : 



210 lbs. copper sulphate @ $6.25 per cwt $13 12 



Lime 1 00 



257 lbs. sal soda @ 1^4 cts 3 22 



20 lbs. arsenate of lead @ 11 cts 2 20 



54 lbs. white arsenic @ 9 cts 4 86 



50 hrs. labor for man @ 15 cts 7 50 



40 hrs. labor for team @ 20 cts 8 00 



Wear on sprayer 8 00 



Total $47 90 



Expense of spraying one acre four times, $4.68. 



The test rows (var. Rose of Erin) yielded as follows : 



Two sprayed rows, 224 lbs.= 69 bu. per acre. 



Two check rows, 199 lbs.= 61.3 bu. per aero. 



Gain from spraying, 7.Y bu. per acre. 



The low yields were due, largely, to the severe drought and 

 early frost. With potatoes at 75 cts. per bushel spraying ap- 

 parently resulted in a net profit of $1.09 per acre. 



