344 iSTATE BOARD OF AGRICULTURE 



SEED SELECTION 



Growers generally have paid little attention to the careful selection of 

 seed potatoes. In many cases culls or unmarketable potatoes have been 

 used for seed purposes. Continued indiscriminate planting of the screenings 

 or small potatoes results in the production of poor yields, of inferior quahty. 

 Many potato diseases such as mosaic, leaf roll, etc., produce small potatoes. 

 Growers should be sure that what small seed they use comes from strong, 

 healthy and productive hills. 



For seed purposes, potatoes should be free from varietal mixtures and 

 diseases, and should come from vigorous, high yielding plants. In selecting 

 seed potatoes from the bin, the grower cannot tell whether the stock selected 

 came from good or poor hills. 



Fig. S. Five hills of potatoes showing variation in yield and quality. Improve the yield and quality 

 of the crop by selecting the best hills for seed purposes. 



The hill selection method of obtaining good seed is one of the most effective 

 and economical ways of increasing the yield and bettering the quality of the 

 potato crop. A very satisfactory way to carry out this method is to set aside 

 a portion of the field as a seed plot. The area of this plot will be determined 

 mostly by t'he acreage of potatoes ordinarily grown. An area equal to about 

 one-tenth that of the total acreage will usually prove sufficient. The seed 

 plot is cultivated and sprayed the same as the regular potato field. During 

 the growing season the seed plot is gone over several times, and all weak, 

 diseased and off-type hills, including both vines and potatoes, are removed 

 from the field. This process is termed "roguing." It is important that the 

 last roguing be done shortly before the vines mature or before they are killed 

 by frost, as some diseases such as Fusarium wilt, black leg, "giant hill," 

 etc., may not show until late in the growing season. At harvest time the 

 seed plot should be dug by hand, keeping the hills separate. Those hills 

 that have approximately four or more uniform sized tubers of ideal type that 

 average approximately six to twelve ounces in weight should be saved and 

 planted the following year in a seed plot. It should be remembered that the 

 number of potatoes a hill produces is determined largely by the number of 



