28 ANNUAL, REPORTS, OF DEPARTMENT OF AGRICULTI'RE. 



start in the sprinjr on the common barberry phint, and a s'ijroroiis cam- 

 pai<rn, therefore, is beinfj; con(hicto(l. in cooperation with the various 

 States, to eliminate such j-ilants. More than 4,000,000 barberry 

 bushes have been located and of these 3.500,000 or more have been 

 ■destroyed. Pro^ifress also has been made in developing a method 

 for controllinfj wheat scab, which caused in 1919 the loss of nearly 

 60,000,000 bushels of wheat; a convenient method of testing; seed 

 corn for germination and of eliminating disease infection before 

 planting has been devised: and much has been accomplished in work- 

 ing out practical control measures for other injurious plant diseases. 



INSECTS. 



The work of controlling insect outbreaks has presented many dif- 

 ficult and complex problems. The task, begun in 1917, of extermi- 

 nating the pink boUworm, which experts in this and other countries 

 regard as probablj^ the most destructive pest of cotton, gave promise 

 of success; but a new and serious situation has been presented 

 by the discovery of the insect in a district in Louisiana not hereto- 

 fore known to be infested and by its reappearance in southeastern 

 Texas. The efforts to eradicate the pest are being prosecuted as 

 vigorously as possible, but they are necessarily handicapped by the 

 failure of the State of Texas to establish and enforce noncotton zones 

 in the infested areas. Whether eradication can be accomplished 

 in the circumstances is problematical, but, nevertheless, no steps 

 should be omitted to prevent the additional drain on the South's 

 most important money crop which the spread of the pink bollworm 

 to other sections of the cotton belt would involve. 



The boll weevil causes enormous damage to the cotton crop. But 

 the Department's experts, after many years of painstaking experi- 

 ments, have now found a successful method of controlling the pest 

 by dusting the plants with calcium arsenate. As a result, the manu- 

 facture and sale of this product has reached very large proportions. 

 Through its enforcement of the insecticide and fungicide act, the 

 purpose of which is to insure a high standard of purity and efficiency 

 in insecticides and fungicides used in combating plant diseases and 

 insects, the Department is keeping off the market a great many 

 tons of calcium arsenate of poor grade which, if used, not only would 

 fail to control the boll weevil but would seriously damage the cotton 

 plants^. 



THE CORN BORER. 



The campaign against the corn borer, a dangerous enemy of corn, 

 is actively under way. The insect, so far as now known, is apparently 

 confined in this country to New England, New York, and a township 

 in Pennsjdvania, and everything possible must be done to prevent 



