194 Report of the Botanical Department of the 



growers are using it, also, as a fungicide on the foliage of pears, 

 plums, currants and gooseberries. 



With the rise in popularity of lime-sulphur as an orchard spray 

 there has arisen the question as to its value in the potato field ; that 

 is to say, How does it compare with bordeaux as a spray for pota- 

 toes ? For orchardists who also grow potatoes it would be conven- 

 ient to use in the potato field the same spray mixture that they 

 use in their orchards. Besides, when used at a dilution of 1 to 40, 

 lime-sulphur is somewhat cheaper than bordeaux. 



Some potato growers have already used lime-sulphur extensively 

 during the past two or three years and a few have experimented 

 with it more or less ; but, as yet, few, if any, carefully conducted 

 experiments with lime-sulphur on potatoes have been reported. 

 Clinton states^ that, in Connecticut, in a season when there was 

 but little blight, commercial lime-sulphur did not prolong the life 

 of the vines or give increased yield while bordeaux mixture did 

 both. In the Vermont experiment conducted by Jones and Gid- 

 dings^ the self-boiled lime-sulphur (Scott's mixture) was used in- 

 stead of the concentrated lime-sulphur solution with which we are 

 dealing here. 



Lead benzoate was included in the experiment because a manu- 

 facturer of this substance claims that it possesses marked fungi- 

 cidal properties. 



PLAN OF THE EXPERIMENT. 



Including an outside row and a row which fell in a dead-furrow 

 (Row 13) there were 22 rows of potatoes in the experiment. The 

 rows were 412 x 3 ft., 35.24 rows being required to make an acre. 

 Adjoining the experiment field on the west was another potato 

 field which made an outside row on that side unnecessary. 



Rows 2, 6, 10, 15 and 19 were sprayed with bordeaux. 



Rows 3, 7, 11, 16 and 20 were sprayed with lead benzoate. 



Rows 4, 8, 12, 17 and 21 were sprayed with lime-sulphur. 



Rows, 1, 5, 9, 14 and 18 were used for checks. 



1 Clinton, G. P. Report of the Station Botanist 1909-1910. Conn. Sta. 

 Rpt. 1909-1910, Part 10:743. 1911. 



2 Jones, L. R., and Giddings, N. J. Vt. Sta, Bui. 142:112-114. 1909. 



