208 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Baait, 35.5; Fiiltz, 47.5; Hard Federation, 72.5; Federation, 90.9; 

 l\ed Cross, 85.4; " Salzer's 1^-izetaker," 75.7. (2) Slightly suscepti- 

 ble — Biinyip, 2; Little Club, 2; Marquis, 7.8; Sonora, 1.9; White 

 Australian, 4.1; Kanred, 5.4; Mealy, 2.2. (3) Free from smut — 

 Cedar, Comeback, Early Defiance, Florence, (italgalos, Fulcaster, 

 Poole, Red Kock, and lied May. 



Program for control and eradication. — Plans for the prevention of 

 its spread beyond the quarantined area and for the final eradication 

 of leaf smut have been developed in cooperation with the Illinois 

 State Department of Agriculture and the Illinois Agricultural Ex- 

 periment Station. The plans agreed upon to accomplish these two 

 purposes are: 



(1) Thoroughly treat all grain with formaldehyde as it comes 

 from the separator. This treatment results in making the grain 

 worthless for seeding purposes, but does not materially affect its 

 milling qualities. 



(2) Burn all straw in the quarantined area as soon as possible 

 after thrashing. 



(3) Sow no Avheat on infested fields and, so far as possible, sow 

 no wheat on land which grew wheat this year. The infected stalks 

 wither before the wheat ripens. As a result, large numbers of 

 them fall out of the sheaves in harvesting and hauling, so that a con- 

 siderable quantity of infested material is left on the land. 



(4) Obtain seed from localities known to be free from leaf smut. 



(5) Treat all seed by the copper-sulphate, or bluestone, method 

 (dipping the grain in a bluestone solution of 1 pound to 5 gallons 

 of water, and then in a solution of lime, 1 pound to 10 gallons). 

 After this treatment the seed remains coated witli the bluestone 

 and lime, and this coating protects it to a large extent from infection 

 b}^ spores possibly present in the soil. 



(6) Grow varieties that are highly resistant to leaf smut, so far 

 as known. 



POTATO WART. 



The potato-wart investigations, conducted cooperatively by this 

 bureau and the Pennsylvania Agricultural Experiment Station, 

 yielded important and encouraging results during the past year. Tests 

 of a large number of commercial American varieties of potatoes, 29 

 English varieties, and a number of promising new seedlings in wart- 

 infested gardens showed 10 of the more or less extensively grown 

 American varieties, including Irish Cobbler, Green Mountain, Sut- 

 ton's Flourball, Early Petoskey, Ehnola, Extra Early Sunlight, 

 Spaulding No. 4, Green Mountain Jr., Round Pink Eye, and Keeper, 

 to be immune to the disease. All the English varieties and 7 of the 

 new seedlings also proved to be immune. Of the English varieties, 

 only 7 gave good yields, and only 1 gave a yield that compared 

 favorably with that of the commercial American varieties. Soil- 

 sterilization experiments showed that it is possible to kill the wart 

 fungus by exposure to live steam under an inverted pan for 85 

 minutes with a pressure of 90 pounds. The indications are that a 

 combination of formaldehyde and steam will be more effective than 

 either treatment alone. These preliminary experiments indicate that 

 there is much hope of eradicating the disease, at least in all the out- 

 lying infestations where one or only a few gardens are found in- 



