No 6 DEPARTMENT OF AGRICULTURE. 709 



trolled very gieatly by the Labit of the variety. We exercise some 

 control through the number of eyes left on a seed piece, but even 

 when we cut to a single eye the necessary closeness of the hills may 

 give too many setts, and the small cutting is quite apt to give a vine 

 lacking vitality to bring to full size all tbe setts it may make. Some 

 varieties are faulty to a marked degree in this respect. Others may 

 set too scantily. But there should be insistance upon the point that 

 we usually have too many tubers in the hill. A little calculation 

 will make this clear. "Where w^e have ten thousand hills in drilled 

 rows on an acre, and have in each hill three tubers averaging tw'o- 

 thirds of a pound each, we have a yield of 333 bushels per acre. 

 In reply, the usual remark of the grower is that many hills will not 

 have any marketable potatoes, and other hills must be large to make 

 the average fair. If this is so ,the fault lies not with the thrifty 

 hills, but with the failures, and it is our business to make ninety- 

 five hills out of every hundred do their full share. I should have 

 likedi to eay "every hill," but while this is entirely feasible in limited 

 plantings, I do not, in my own experience, find it safe to expect a 

 solid stand of thrifty plants, no matter how much reasonable care 

 is exercised. With some lots of seed, and especially with budded 

 seed, this may be approached so nearly that it is practically perfect, 

 but in the usual field plantings we use some seed pieces that do not 

 grow at all or fail for some reason to make a crop. However, it is 

 only a fair expectation that ninety-five hills out of one hunda-ed will 

 make a fair yield when we use all reasonable precautions as to soil, 

 seed, planting and tillage. With a full stand of plants, the number 

 of setts made by a single vine should be small, and a highly desirable 

 quality in a variety is a disinclination to set as freely as seedsmen 

 give assurance that it will do. A point of superiority in the 

 second-crop seed of the south is its failure to set as abundantly as 

 ripened northern potatoes. It can push to good' size all the tubers 

 it forms, if soil and season favor, and the good yields obtained are 

 due to the good size of the tubers rather than to an abnormal num- 

 ber of undersized potatoes. 



Kesi^ant Varieties. — In the selection of varieties resistance 

 against effects of drouth, disease and insects, is one of the important 

 considerations. A potato may be prolific and of high quality when 

 the season is entirely favorable, and yet be one of the most worth- 

 less of varieties in an unfavorable season. The variation in resist- 

 ance to drouth and to disease is marked. As soils grow older, drouth 

 affects them more quickly, and as potatoes continue a leading crop 

 of a locality, diseases become established. In selecting a variety for 

 main crop I want to know that it will do relatively well in a bad 

 season. In years of abundance the potato-growler finds prices too 

 low for much profit, and he learns to diepend upon other years for 



