358 ANNUAL REPORT OF THE Off. Doc. 



the United States to use it, beginning in the fall of 1904 by digging 

 about 300 bushels with hooks and saving the best hills. The follow- 

 ing year this selected seed gave an increased yield and greater market 

 value. I have found the profit from seed selection to be even more 

 from the increased sale value than from the better yield. The cost 

 is very small, consequentlj^ the net profit above cost is large in pro- 

 portion. 



We are always on the lookout for some new variety which should 

 displace those we have now as these in their time drove out the 

 Burbank and Early Rose, themselves successors to now forgotten va- 

 rieties. Many thousands of new seedlings have been, and are con- 

 stantly being tried out. From these a list of less than a dozen 

 varieties can be made out which are superior to all the rest. The 

 chance against getting a new seedling variety better than those we 

 now have is in the same proportion of thousands to one. 



We have always thought of a potato variety as something un- 

 changeable, though with also the belief that sooner or later it must 

 "run out." Seed selection has now proved that varieties are made 

 up of many separate strains, differing more or less, with further var- 

 iation going on most of the time. From these variations within a 

 variety we can select and keep up a strain having the particular 

 qualities most suited to the needs of any grower, in the same way that 

 we now select the variety most suited to our conditions. It is now 

 believed that unless a variety is grown under unfavorable climatic 

 or other conditions that it will keep its vigor indefinitely. One 

 variety has been grown in Sweden over one hundred and fifty years. 



Conditions in the United States are often poor. In their original 

 home in South America the growing season was long, wet and cool. 

 The tubers were small, and but little drain on the strength of the 

 plant. Out of the many thousands of varieties produced we have 

 kept for our use only those that produce very heavy crops of tubers 

 in one half or one third of the time required by the original potato 

 plant. In connection with our hot and dry climate this throws a 

 very severe strain on the vitality of the potato. It is not strange 

 that some plants break down and produce tubers nearly worthless 

 for seed. In northern Europe the great ocean current, called the 

 Gulf Stream, makes the climate much more favorable to the potato 

 than here. Yet differences in vigor are seen even there as tests be- 

 tween seed from the north and south of Great Britain show. In our 

 South the summer heat is so great that potatoes maturing a,t that 

 time are nearly worthless for seed. When planted in the same 

 section so as to mature in the cool weather of fall, good seed results; 

 the so-called "second-crop" seed. Even as far north as Ottawa, 

 Canada, dry and hot weather in 1906-7-8 ruined the varieties grown 

 there. I Relieve that qroicers should, study every possible means of 

 maintaining vitality of potatoes in hot and dry seasons. Not only 

 is the crop reduced at a time when prices are highest, but the seed 

 is injured for the following years. 



We find that our varieties are constantly developing new strains 

 in each, some valuable and some degenerate. We can prevent in- 

 jury and store up vitality by growing them under as favorable condi- 

 tions as possible. Then by the use of different methods of seed selec- 

 tion we can find and use as seed each year the best yielding and sell- 

 ing strain of the variety most suited to our climate, soil and markets. 



