MICHIGAN EXPERIMKNT STATION BULLETINS. 



POTATOES. 



Bulletin No. 85, April, 1892. 



For three years considerable attention has been given to experiments 

 with potatoes, the work including, in addition to variety tests embracing 

 nearly two hundred market varieties, a line of experiments covering a 

 greater portion of the methods of culture, such as depth of planting, 

 manner of cutting seed, amount of seed, distance of planting, manures 

 and fertilizers, and manner of application, etc. 



In 1889 the season was quite favorable, and very even and fairly relia- 

 ble results were obtained, while in 1890 and 1891 the crops suffered from 

 extremely hot, dry weather, so that the yields were low, and while the 

 results obtained seemed reliable, and could be readily explained by the 

 character of the season, the conclusions that might be drawn from them 

 would only hold true in similar seasons. The past year, in particular, our 

 variety tests were hardly satisfactory, as, although the appearance of the 

 plats was promising up to the 15th of July, the severe drouth that set in 

 at that time caused them to ripen ijrematurely, and made it almost impos- 

 sible to learn as to the seasoa of the varieties. The late varieties were at 

 the height of their growth, and as the vines were withered and dry within 

 a week after the hot weather of the first of August, the yield was greatly 

 reduced. 



The land upon which the potatoes were grown was in excellent tilth 

 and of more than average fertility. No manure or fertilizers were used, 

 except in the plots specially set aside for the purpose. The land was a 

 deep, well-drained, heavy sandy loam, and grew a crop of winter squashes 

 in 1890, almost without manure. The soil was much above the average of 

 the state^ and the care given the crop was the very best. 



TEST OF VARIETIES. 



The variety test included one hundred and forty-two sorts, of which 

 ninety-two had been grown for at least one year previously. The fifty 

 new kinds were obtained from D. C. Hicks, No. Clarendon, Vt., Hiram 

 Presley, Port Huron, and H. C. Markham, Ann Arbor, Mich. 



The usual amount of seed of each kind planted was two pounds, in one- 

 ounce pieces, but in a few cases only one pound was obtained. Whatever 

 the amount of seed potatoes used, the weight used in each hill was the 

 same. When the full amount was planted they were given a space of 33 

 feet in the row, and three feet two inches between the rows. The land was 

 furrowed five inches deep, and the seed pieces, dropped in the bottom of 

 the furrow, were covered two inches. The planting of the varieties was 

 done on the 15th of May, and they were harvested the first week in Sep- 



