520 ANNUAL. KEPORTS OF DEPARTMENT OF AGRICULTURE. 



foreign countries, a hearing on the subject of these two diseases 

 was held March 25, 1919. It was pointed out in the notice of hear- 

 ing that the take-all disease was widely prevalent in Australia and 

 reported to occur also in Italy, France, Belgium, Great Britain, 

 Ireland, and Brazil. The flag smut disease was known to exist 

 in Australia and also in India and Japan. The flag smut is a dis- 

 ease of wheat. The take-all disease may infest, in addition to wheat, 

 oats, barley, rye, and rice. 



The flag smut affects the leaf blades, leaf sheaths, stems, and 

 sometimes the spikes of wheat. Usually every shoot is affected, the 

 leaves whither, and the spike is frequently replaced by a mass of 

 twisted leaves. The spores are carried on the seed and live over in 

 the soil. In portions of Australia the losses from this disease run 

 from one-tenth -to one-half of the crop. 



The take-all disease, known also as whitehead or foot rot, attacks 

 the roots and the bases of the plants, rotting the roots and blackening 

 the base of the stem. Young wheat plants speedily wither and 

 die ; older ones may survive but rarely produce grain. Heavy losses 

 have been sustained in all countries where this disease occurs. 



The risk of introduction of these two diseases was largely from 

 the possible importation of any of the grains mentioned for seed 

 purposes. War conditions, however, had led to some commercial 

 importations of wheat from Australia and there was a possibility of 

 further commercial shipments from this source on account of the 

 large accumulations of wheat in that country. 



The hearing on this subject brought out rather distinctly the need 

 of controlling the entry of foreign wheat, either for food or for plant- 

 ing purposes. The promulgation of the quarantine was postponed 

 pending the determination of the practicability of disinfecting wheat 

 from the countries under consideration as a basis for fixing 

 the restrictions which would be placed upon the entry of such 

 wheat. On the completion of this inquiry the quarantine was 

 promulgated July 2, 1919, effective August 15, 1919, with regu- 

 lations governing the issuance of permits, sterilization, and other 

 conditions of entry. This quarantine prohibits the importation of 

 seed or paddy rice, but places no restriction on the importation 

 of husked or polished rice imported for food purposes. 



THE FLAG SMUT AND TAKE-ALL DISEASES IN THE UNITED STATES. 



While the steps described were being taken with respect to the 

 control of the entry of foreign wheat, these two diseases, flag smut 

 and take-all, were discovered to be already present in southern 

 Illinois and the take-all disease in Indiana, the evidence seem- 

 ing to indicate that they had been in southern Illinois for two 

 or three years. The source of entry of these diseases into this 

 country has not been determined, but it is believed to have been 

 through some importation of seed wheat from Australia or other 

 foreign country. This discovery was followed up by an inten- 

 sive investigation of the principal wheat-growing areas of the 

 United States in which the board cooperated with the Bureau of 

 Plant Industry and with the officials of the several States con- 

 cerned. These field investigations failed to demonstrate the occur- 

 rence of these diseases at that time at any other points, and this situa- 



