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150 AGRICULTURAL APPROPRL\TION BILL, 1924 



point where the ehmination of seed-borne diseases has become 

 vitally important. 



The superficial diseases, the fungi which cause scab and troubles 

 of that character on the skin, are under measurable control through 

 the dipping of the seed and the avoidance of limy soils, or the omis- 

 sion of liming the soils immediately before the potato crop is to be 

 grovMi. But certain of the most destructive diseases — and these 

 have appeared in relatively recent times — both in Europe and this 

 countr}' — their control is much less well understood. They are 

 knowTi roughly as the virus diseases, which it is now known are trans- 

 mitted from plant to plant bj^ certain insects, the little aphids or 

 plant lice; ana it is now known, also, that at least one of these insects 

 overwinters on the rose. This whole virus disease problem as affecting 

 the potato is intimately associated with the production of high-grade 

 seed potatoes. 



Much of the more southern portion of the country, including parts 

 of the Corn Belt and most of the territory south of the Potomac River, 

 relies on northern seed potatoes for its planting stock — Maine, New 

 York, Michigan. Minnesota, and Wisconsin. 



The strategic place, therefore, of the attack for the control of these 

 diseases is that seed-potato-growing territory. The problem is acute 

 also in California, where the source of supply is either the high alti- 

 tudes of their own State or Oregon and Washington. A very great 

 interest in this matter has developed under the leadership of the 

 Bureau of Plant Industry, which some 10 years ago suggested the 

 idea of field inspection during the growing season as a basis for certi- 

 fication of seed potatoes, both as to horticultural purity as regards 

 variety and pathological cleanness. So that there were this last year 

 over a million and a half bushels of certified seed potatoes produced, 

 mostly in those Northern States. 



But the situation is really critical now as regards the permanence 

 of the certified seed plan; it is a sound idea, one that we are confi- 

 dent is the only way through w^liich these diseases can be controlled. 

 We need more knowledge of the basic facts regarding these diseases 

 as a basis for the field inspection upon w^iich the certification rests. 

 A meeting is to be held in Boston tne last week of December of the 

 potato pathologists and certified seed growers of the States to con- 

 sider this whole question and endeavor to get together upon a more 

 harmonious and uniform plan of certification. 



Mr. Buchanan. Don't you think the department ought to be 

 very cautious and very certain before it fjives certificates^ 



Doctor Taylor. That is realized, and the department has refrained 

 from giving certificates at all covering cjuality or pathological clean- 

 ness of seed. We have not specific statutory authority for that. 

 It is likely that if the name of tlie department appeared upon such a 

 certificate it would be interpreted as signifying a guarantee of 

 quality, which, under the j)resent conditions, could not be given; 

 and, accordingly, the department has studiously and without devia- 

 tion refrained from certifying seed potatoes or seed of any kind. 



Mr. Andkhsox. Where vou have developed the method of control 

 of the di.sease, do ^'ou lind that the method is generally achtpted 

 sufficient interest is taken by the peoj)le in the production of the 

 disease-free potatoes or other commodities, so tliat you methods 

 are adoj)te(l ( 



