AND OTHER INJURIOUS INSECTS OF I907 AND I908. I27 



EXPERIMENT No. 15— CARBOLIC ACID EMULSION. 



Carbolic acid emulsion at the rate of one part of emulsion to thirty 

 parts of water, was used on cauliflower plants both on Station grounds 

 and at a truck garden. The stock solution was made as follows: 



One lb. of hard soap dissolved in 1 gal. of water; 1 pt. crude carbolic 

 acid added, and churned with a force pump until thoroly emulsified. 



Fifty plants in the experimental garden were treated with carbolic 

 emulsion. These plants were set ^lay 17th, and the first treatment made 

 May 18th. The first three treatments were made at intervals of five days. 

 and the remainder at intervals of a week. Eight treatments were made, 

 the last treatment was made July 5th. The emulsion was applied with a 

 garden sprinkling can, with the perforated cap removed. Counts on this 

 plat made July 26th were as follows: 



Head.s ^^jl*!i,^f Missing 



Treated 1 13 36 



Check 6 18 26 



Ten rows of caulifiower, 37 plants to the row. were treated with the 

 emulsion. This was in the same proportion as above — 1-30. The plants 

 were set ]\Iay 21st and treated eight times, beginning the 23rd of 'Slay, and 

 the last treatment was made July 5th. The first three treatments were at 

 intervals of five days, and the remainder at weekly intervals. Counts made 

 August 5th were as follows: 



Heads "^^ll^f Missing 



Treated 250 82 38 



Check 267 69 34 



EXPERIMENT NO. 16— HELLEBORE DECOCTION. 



A decoction of white hellebore was used with considcralile success in 

 the experimental garden in 1907. This decoction was made by steeping 

 2 ounces of hellebore in 1 quart of water for an hour, then diluting it with 

 water to make 1 gallon of the decoction. It was applied with a garden 

 sprinkling can the same way as the carbolic acid and lime mixture. 



Fifty cauliflower plants in our experimental garden were treated with 

 this decoction, and fifty more plants left untreated for checks. The mixture 

 was applied eight times, beginning the 18th of IMay, and the last treatment 

 made July the 5th. The first three treatments were made at intervals of five 

 days, the remainder at weekly intervals. Counts made July 26th showed 

 the following results: 



Plants 



Plants 



Heads Witliout V"", 

 Heads ^^*^" 



Treated Plants 29 18 3 



Check Plants 10 14 26 



These rows were situated in a patch which was badly infested -witli 

 cabbage maggot this year, and the striking difference between treated and 

 check rows clearly shows the direct benefit obtained by the use of the helle- 

 bore decoction. 



White hellebore costs from 20c to 25c per pound at retail, so that the 

 cost of making the decoction itself is comparatively small. At 20c a pound 

 enough of the mixture can be made to treat 1.000 plants at a cost of only 50c. 



