INSECT POWDER. 9 



On the other hand, better results were obtained by persons more 

 famiUar with growing plants. Thus Peter Henderson wrote Riley 

 (222) regarding P. roseum: "I have grown the plant and its varieties 

 for 10 years. It is of the easiest cultivation, either by seeds or 

 divisions. It now ramifies into a great variety of all shades, from 

 white to deep crimson, double and single, perfectly hardy here, and 

 I think likely to be nearly everywhere on this continent." Pyre- 

 thrum roseum was also grown successfully at German to^vn, Pa., and 

 at Archer, Fla. (222), from seed furnished by Riley. In 1884 Riley 

 (225) reported success in growing Pyrethrum in Virginia and in 

 Maryland, and in 1885 (226) in Arkansas and Florida. 



King (155), in 1886, reported the results of efforts to grow P. 

 roseum in different States. At the Connecticut Experiment Station 

 plants from seed sown in 1884 bloomed in 1885, and then died. At 

 the Michigan station the seasons were too cool and short for the 

 profitable growth of this plant. The New York station reported 

 that ''the plants grew well, blossomed, and some of them matured 

 their seed." At the Pennsylvania State College the plants did not 

 bloom. An attempt to grow this plant in Massachusetts is described 

 in the annual report of that station for 1889 (101). The seeds were 

 sown in a hotbed, and subsequently transplanted in the field, but 

 did not mature. In 1891 (102) and again in 1892 (103) it is reported 

 that one row of P. roseum was grown in the field. Goff (104) planted 

 seeds of P. roseum at the Geneva (N. Y.) Agricultural Experiment 

 Station in the spring of 1887. The plants did not blossom the first 

 season, and were counted as a failure, but in the second spring they 

 started a vigorous growth, and bloomed profusely. The powder pre- 

 pared from these New York grown flowers was just as active against 

 flies as that from P. cinerarixfolium flowers grown in California. 

 Green (105) in 1892 recommended P. roseum as an ornamental plant 

 desirable for planting in the region of the Minnesota station. In 1890 

 Massey (192) announced his intention of trying the cultivation of 

 P. roseum and cinerarisefolium at the North Carolina Agricultural 

 Experiment Station, but nothing seems to have come of this. 



California is the only place in the United States where the cultiva- 

 tion of Pyrethrum has reached conunercial proportions. Coquillet 

 (55) states that G. N. Milco introduced the Pyrethrum cinerarixfoJium 

 into Calif ornia about 1870, and describes the cultivation of the plant. 

 The amount of the present production of insect powder in California 

 is not known, but in 1888 it was 52 tons.^ 



Klee (158), of the College of Agriculture of the University of Califor- 

 nia, has carried on extensive experiments on the cultivation of Pyre- 

 thrum. At the Southern Coast Range Culture Substation of the Uni- 

 versity of California, in San Luis Obispo County, Cruickshank (59) in 



1 Insect Life. v. 1, p. 356, 1889. 



