TREATMENT OF CABBAGE PLANTS, ETC. 833 



years the insect was so scarce that very little harm was done to 

 ■ the plants by it, consequently the experiments failed to show any- 

 thing. 



In the spring of 1908, tests of various substances and devices 

 were made on the grounds of Mr. Howard C. Yale at Mount 

 Carmel, where the crop had been troubled each season for several 

 years by the maggot. The tests were made on thirteen rows 

 of plants, each row containing about one hundred and thirty-five 

 plants. The rows extended in a northerly and southerly direction, 

 and at the north end the ground was four or five feet higher than 

 at the opposite end of the field. 



Rows I and 2 were set April i8th, and the plants dipped in 

 lead arsenate (one pound in two gallons of water), Jersey Wake- 

 field in Row I and Henderson's Summer in Row 2. Rows 3 to 

 8 were set about a week later, and Rows 9 to 12 still later, with 

 untreated plants of these varieties. 



On May 14th, Rows 3 and 4 were treated with carbon disul- 

 phide. A hole at least an inch deep was made near each plant 

 and from one-third to one-half a teaspoonful of the volatile 

 liquid was injected from an oil can and covered up. 



Row 5 was left as a check. 



Row 6. On May 4th tarred paper disks were placed around 

 a portion (about one hundred) of the plants, beginning at the 

 north end of the row. These disks were a year old and had 

 become dry and stiff, and consequently did not fit as well around 

 the stem nor as close to the ground as when fresh. On May 6th, 

 placed fresh disks on the remaining plants in Row 6 and on the 

 plants in Row 7. These disks were cut with a knife from a 

 single-ply tarred paper.' 



Row 8, beginning at the north end, seventy-four plants were 

 treated May 6th with the lime-carbolic mixture, made by slaking 

 fresh quicklime, and one quart of the thick cream added to one 

 gallon of water. To this was added about one teaspoonful of 

 crude carbolic acid, as used by Professor J. B. Smith* of New 

 Jersey. The mixture was then sprayed upon the soil around 

 each plant in a circle six to eight inches in diameter. 



On May i6th, all of the plants in Rows 8 and 9 were sprayed 

 with the lime-carbolic mixture. Used eight ounces of lime to one 



* Bulletin 200, New Jersey Agr. Expt. Station, p. 18, 1907. 



