The Cabbage; Root Maggot. 555 



belief that this fertilizer would do much to control the injury from the mag- 

 gots, but it should never be applied close to the plants, but broadcasted. 



Thus there is no experimental evidence from which can be drawn definite 

 conclusions in regard to the action of this fertilizer on the maggots. How- 

 ever, as Mr. Whitehead said in 1892, it has been found valuable, for if it fails 

 to act remedially, it at least stimulates the plant's growth and thus helps it 

 along out of the way of the maggots. Asa killing agent against the maggots, 

 we believe it has no value unless used so strong as to kill the plant also. 



Muriate or Sulphate of Potash. 



In 1887, the editor of " The Rural New Yorker " suggested that Mr. Hen- 

 derson try the muriate on the maggots. In 188S, Mr. G. H. Howard advised 

 that to each plant be applied a gill of a solution made by putting one spoon- 

 ful of the muriate in a quart of water. However, he made the same proviso 

 as to its effectiveness as mentioned above in discussing ashes. In a pamphlet 

 on the " Cauliflower," Mr. Brill says (as quoted from Crozier on " The Cauli- 

 flower") that the muriate is a remedy for the maggots. He dissolved i 

 tablespoonful in a gallon of water and applied one gill of this to the roots of 

 each plant, repeating the application as occasion required. He well says : 

 " Care and judgment must be used not to overdo the matter, thereby killing 

 the plant as well as the maggots. Experiment a little at first." Mr. Brill 

 wrote us in August as follows : " While my experiments with the Muriate 

 of Potash to kill the root maggot was in the first instance a success, yet it 

 does not always have the desired effect. I presume much depends upon the 

 conditions of the worms and the plant when applied." Thus there is noth- 

 ing definite in the evidence either for or against the effectiveness of the 

 muriate on the maggots. We have no faith in the killing or preventive prop- 

 erties of either the muriate or the sulphate of potash unless used so strong 

 as to injure the plant also. 



Kainit. 



This fertilizer was first used against the root maggots at least 7 or 8 years 

 ago. One of its first advocates was Mr. Brill ; his pamphlet on the ' * Cauli- 

 flower " is doubtless the source of the few recommendations which the sub- 

 stance received until within about 4 years. In 1890, Prof. J. B. Smith had 

 his attention turned to kainit as a possible insecticide, and he performed the 

 following experiment with it on the pest under discussion : "A number of 

 cabbage maggots placed on the soil (in a tin can) impregnated with the solu- 

 tion, died within 12 hours." (These were very unnatural conditions.) No 

 further experiments seem to have since been carried on with this substance 

 against the Cabbage Root Maggot. 



Last year Prof. Smith had some of his correspondents experiment with 

 kainit on the Onion Maggot (An. Rept. for 1893. p. 441). He says: "The 

 entire fields were gone over, row by row, and all plants that showed signs of 

 infection were taken out bodily and afterwards destroyed. Then heavy 

 dressings of kainit were applied, with the result that no further traces of 



