1136 A NATIONAL PLAN FOR AMERICAN FORESTRY 



of telling what additional introduced diseases might have entered the 

 country had it not been for this service, or what they might have 

 caused. Had the present regulations and enforcement service been 

 in force 40 years earlier, the loss of our chestnut and the expenditures 

 for blister-rust control might have been postponed for centuries. 

 Some parasites may slip through the most rigidly maintained quaran- 

 tine, but the hazard is very greatly reduced by such service as the 

 Bureau of Plant Quarantine is giving. State inspection authorities 

 can effectively supplement and strengthen this Federal protection 

 service against foreign pests, but they suffer legal disabilities in ex- 

 cluding foreign shipments which make Federal help necessary. 

 Individual States are also handicapped in preventing the spread of an 

 introduced parasite that is already established in some part of the 

 country. For example, State A may refuse or neglect to quarantine 

 against a disease from another region dangerous to adjacent State B, 

 but which if introduced into A will spread naturally into B. Federal 

 interstate quarantines have also been an important part of the effort 

 to delay the spread of the blister rust within the United States. 



The most direct efforts to aid the States in the control of a forest 

 disease have been in connection with the white pine blister rust. 

 The Federal Government initiated the control campaign against this 

 disease; it furnishes each cooperating State with one or more men 

 who act as control leaders under the administrative direction of the 

 proper ^ State official (usually the State forester), to furnish technical 

 supervision of control work, perform necessary experiments to im- 

 prove control practice, scout for blister rust, and disseminate technical 

 information on the disease and its control. Each cooperating State 

 furnishes men directly to supervise the control jobs lined up by the 

 State control leader, gives administrative direction to all control 

 work, and, when necessary, reimburses owners for the loss of produc- 

 tive currant and gooseberry bushes destroyed in control application. 

 Each owner desiring to protect his pines from blister rust furnishes the 

 labor to pull the wild and cultivated currant and gooseberry bushes 

 growing within 900 feet of the pines, under the direction of a foreman 

 furnished by the State. 



The acreage cleared of currant and gooseberry bushes in the United 

 States from 1916 to 1932, inclusive, totals approximately 10,600,000 

 acres, consisting of 9,077,271 acres of complete initial control work, 

 934, 329 acres given a second working to maintain control, and 674,756 

 acres of incomplete initial control work (concentrations of currants 

 destroyed with chemicals on 7 percent of this land, along streams). 

 This work has resulted in completely protecting approximately 

 6,000,000 acres of white-pine forest, with partial protection to such 

 pine as may be present on the additional 3,700,000 acres in the protec- 

 tion zones and along stream bottoms from which the currants were 

 cleared. The total cost of all control work to the end of 1932 (Federal 

 State, and private expenditures) amounts to $8,307,000, or 83 cents 

 per acre for the area actually cleared of currant and gooseberry bushes. 



On the basis of 6,000,000 acres of protected pine, the cost averages 

 $1.39 per acre of pine land. Of the latter amount, 24 cents (17 per- 

 cent) was Federal funds for development of control methods and for 

 general service activities such as scouting and quarantine enforce- 

 ment; 55 cents (40 percent) was Federal funds for direct cooperation 

 with the agencies applying control; 55 cents (40 percent) was expended 



