BUREAU OF PLANT INDUSTRY. 155 



(3) In Ohio, Indiana, Michigan, Wisconsin, Minnesota, Iowa, and 

 South Dakota the disease has been found at various times during the 

 past six years in 71 localities. In 68 of these localities the disease 

 has been eradicated and eradication is now in progress at the 3 re- 

 maining localities. The 71 localities are distributed by States, as 

 follows : Ohio, 3 ; Indiana, 1 ; Michigan, 3 ; Wisconsin, 13 ; Minnesota, 

 49; Iowa, 1; South Dakota, 1. The disease has so far this season 

 appeared in only one of the localities where it has been previously 

 eradicated. It is believed that this record shows a substantial achieve- 

 ment and indicates that the disease can be confined to the East, at 

 least for many years. 



(4) In all remaining States the blister rust is yet to be found. 

 This includes the States of Delaware, Marjdand, West Virginia, all 

 Southern States, and all States west of the Mississippi River except 

 Iowa, Minnesota, and South Dakota. In all of these States an or- 

 ganized search for the disease has been made during the past two 

 seasons. 



CHESTNUT BLIGHT. 



Several American chestnut trees have been located which are ap- 

 parently highly resistant to the chestnut blight. This gives a promise 

 of obtaining, by selection and propagation, a strain of American 

 chestnuts which can be used for reforestation. Hitherto resistance 

 has been found only in oriental species, which, while suitable for nut 

 production, are too small for timber uses. 



CITRUS CANKER. 



Since the autumn of 1914 the bureau has been cooperating with 

 the Gulf States in a campaign for the eradication of the canker dis- 

 ease of citrus fruit and trees. 



Throughout the last three j^ears great emphasis has been given to 

 the necessity of unusual precautions and constant care to prevent 

 the spread of canker, which is extremely infectious to all kinds of 

 citrus trees. The progress of the work has been very satisfactory, 

 and there appears to be no doubt that the few infections occurring 

 in South Carolina and Georgia havd been eradicated, so that further 

 work in these States will not be necessary. The amount of infection 

 in Florida, Alabama, Mississippi, Louisiana, and Texas has been 

 very greatly reduced, and while very thorough scouting ancl inspec- 

 tion will be necessary in these States, in order to locate promptly 

 scattered infections which may occur, it is believed that further 

 seriously destructive outbreaks of canker can be prevented. 



ALFALFA YELLOWS. 



Studies on the " yellowing " of alfalfa are being continued in the 

 East, with special attention to strains that are apparently resistant 

 to this disease. Seed of a number of hybrids of Medicago sativa, 

 Peruvian variety, ?ind 31 edicaga falcata has been sown in the West 

 with a view to increasing stocks of the most resistant strains to the 

 point where field tests can be made in the East. 



