21 



During 1905, in addition to the 405 acres mentioned, about 50 acres 

 were used in 12 farms near Clarksville, Tex., in a cooperative test 

 of the corn trap-crop system, and several small areas were used in 

 cooperative work in other localities. 



Upon these experimental farms an endeavor was made to demon- 

 strate the value of the several remedial measures outlined in the pre- 

 ceding pages, under " Means of Control." 



In all of the experiments conducted in 1905 the results, as shown 

 by final yields, were supplemented by observations throughout the 

 season upon the relative earliness of and comparative bollworm in- 

 jury to the plats receiving various treatments. The results of these 

 observations conform closely with the final yields and strongly em- 

 phasize the value of improved methods in protecting cotton from 

 bollworm injurj^ These observations include cotton grown on the 

 principal types of soil of northern Texas. 



At the time of examination the injury to late planted cotton and 

 to cotton raised from degenerate seed varied from 12 to 49 per cent, 

 and to early planted cotton and cotton grown from improved seed 

 the injury varied from 1 to 23 per cent. 



To illustrate the decided preference of the bollworm for the less 

 mature fruit, of a total of 24,292 squares and bolls examined in sev- 

 eral localities, those one-half grown or less numbered 20,789, of which 

 number 20.4 per cent were injured; the bolls over one-half grown 

 numbered 3,504, with 7.2 per cent injured. The contrast between 

 the percentages of injury would have been still greater had the exami- 

 nations been made two weeks earlier, as a considerable number of the 

 injured squares and bolls had fallen and were buried by cultivation, 

 while the majority of the more mature fruit was retained by the 

 plant even though badly injured. 



ARDMORE FARM. 



The experimental area on the farm of Mr. S. A. Brown was located 

 oil a typical sandy soil of the cross timber region and consisted of 

 ten 4-acre plats. 



The experiment consisted of comparing the King and Rowden 

 varieties now becoming so generally adopted in the bollweevil and 

 bollworm districts of Texas with the much later big-boll sorts from 

 gin-run seed. The effect of commercial fertilizers upon the early 

 maturity and total cotton production was also studied. Three stand- 

 ard commercial fertilizers were used in the experiment: (1) A com- 

 plete fertilizer, showing by analysis 8 per cent available phosphoric 

 acid, 2 per cent potash, and 2 per cent nitrogen; (2) a compound of 

 acid phosphate and potash without nitrogen, the analysis of which 

 showed 10 per cent available phosphoric acid and 4 per cent potash; 



290 



