49 



In seven out of the nine years, those potatoes which were sprayed 

 with Paris green and water surpassed those which were sprayed with 

 Paris g"reen and plaster, in yield of crop per acre. It is also quite notice- 

 .able that in each of the nine years the untreated potatoes g"ave decidedly 

 the lowest yield of tubers per acre. The Bug Death, which has only 

 been tested in our trial grounds for the past three years, is manufac- 

 tured at St. Stephen, X.B., and has been used to a limited extent 

 throughout Ontario during the last two or three years. The potato 

 tops on which Bug Death was applied were more vigorous in growth 

 and greener in appearance throughout each of the seasons than those 

 on which the other applications were made. In this respect, the Bug 

 Death exerted an influence about equal to a combination of Paris green 

 and Bordeaux mixture in each of the past two years. The usual 

 prices of these insecticides, when bought in quantity, are about as fol- 

 lows ! Paris green, 20 cents ; Bug Death, 7 cents ; and Potato Bug 

 Finish, i 2-3 cents per pound. The cost, therefore, for the material 

 used in the experiments conducted in 1902, 1903, and 1904, was about 

 as follows : Paris green and water, 60 cents ; Paris green and plaster, 

 88 1-2 cents; Bug Death, §6.72; and Potato Bug Finish, §1.00 per 

 acre. 



Treatment of Potatoes to Destroy the Scab. An experiment 

 was again conducted in 1904 by immersing scabby potatoes in a solu- 

 tion of corrosive sublimate for one and a half hours, after which they 

 were spread out to dry ; they were then cut and planted in the usual 

 way. The treatment was made with each of two varieties. Both the 

 treated and untreated potatoes were planted at the same time and in the 

 usual manner. The corrosive sublimate solution was made by dissolv- 

 ing corrosive sublimate in hot water in the proportion of 2^ ozs. of the 

 former and two gallons of the latter. The solution was allowed to 

 stand twelve hours, after which it was diluted with 13 gallons of water. 

 As the corrosive sublimate is very poisonous, the material itself should 

 be looked after very carefully and no potatoes which have been treated 

 should be left unplanted. As none of the potatoes had more than one- 

 half of one per cent, of scab in the crop of 1904, the results of this ex- 

 periment do not furnish much information for this season. Taking the 

 average of four years' results, the potatoes which were treated with 

 corrosive sublimate gave about 7 bushels per acre more than those on 

 which the corrosive sublimate was not used. This treatment has been 

 used with good satisfaction in some places where there is usually a con- 

 siderable amount of scabby potatoes. 



Planting Different Sized Pieces at Different Distances 

 Apart in the Rows. ,For three years in succession, an experiment has 

 been conducted by planting one, one and a half, and two ounce pieces 

 of potatoes. The potatoes of each of these sizes were planted twelve, 

 eighteen, and twenty-four inches apart in the row. The average re- 

 sults show that the yield per acre increased in the order of the increase 



4 Bull. "° 



