THE SO-CALLED TOBACCO WIREWOEM IN VIRGINIA. 27 



found in the check row of 30 plants. The number .of plants treated was not large 

 enough to make this test of much value. 



In the second experiment kerosene was mixed with sand and a small amount 

 sprinkled around 100 tobacco plants. One hundred plants in an adjoining row were 

 used as a check. A light rain fell a few hours after the sand was applied. On June 

 18, eight days after treatment, the plants were examined. Sixteen were found 

 injured in the treated row and 22 in the untreated row. 



KAINIT. 



In one experiment kainit was mixed with the soil in the hill before planting. Too 

 large a quantity of the kainit was used in the test, as a considerable number of plants 

 failed to grow. One hundred tobacco plants were put out in soil mixed with the 

 kainit, and 100 plants in an adjoining row were left for a check. A number of infested 

 plants were found where the kainit had been used, the substance evidently not being 

 of much value as a preventive, as the worms often enter the plant at the "bud" or 

 whorl of terminal leaves. 



TURPENTINE. 



In certain sections of Tennessee and Kentucky turpentine is said to have been used 

 as a repellent for Crambus larvae and cutworms. Before planting, the roots of the 

 tobacco plants are dipped in water in which a small quantity of turpentine has been 

 stirred . 



A test on 1 acre of tobacco was made by Mr. Charles Armistead, of Clarksville, Tenn., 

 and the field kept under observation by the writer. Entirely negative results were 

 obtained. The following are details of the experiment: The tobacco was on weedy 

 land containing an abundance of white top (Erigeron annum) and plantain. The 

 first planting was entirely destroyed. When the tobacco was replanted turpentine 

 was used at the rate of 1 teaspoonful to 1 gallon of water, the roots of the plants being- 

 dipped in the mixture. On June 27, two weeks after planting, the tobacco was 

 examined. Worms were still very numerous. Over 80 per cent of the plants had 

 been entirely destroyed, in both treated and check plats. There seemed no apparent 

 difference in infestation and damage between the treated tobacco and that on which 

 no turpentine had been applied. 



CALCIUM CYANAMID. 



Calcium cyanamid (lime nitrogen) is said to have a repellent or poisonous effect 

 upon insects, and on the suggestion of Mr. E. H. Mathewson, Crop Technologist of the 

 Bureau of Plant Industry, Mr. B. G. Anderson, superintendent of the Tobacco Experi- 

 ment Station at Appomattox, Va., and the writer made a test of the material during 

 1 911, using the calcium cyanamid at the rate of 300 pounds per acre. The land selected 

 had not been cultivated for several years. There was a rank growth of buckhorn 

 plantain, oxeye daisy, and stickweed, and Crambus larvae were exceedingly numer- 

 ous, making conditions ideal for the test. The plat, containing one-twentieth of an 

 acre, was divided into series of two rows each. The calcium cyanamid was used on 

 two rows and the next two rows were kept as a check. On the treated rows com- 

 mercial fertilizer at the following rate per acre was used : 



Pounds. 



Calcium cyanamid 300 



Acid phosphate , 600 



Sulphate of potash 100 



On the check rows the fertilizer used (rate per acre) was as follows: 



Pounds. 



16 per cent blood 300 



Acid phosphate 600 



Sulphate of potash , 100 



