144 AGRICULTURAL EXPERIMENT STATION. [Jan. 



The lands were i)loughed and harrowed during the first 

 week of INIay, and the potatoes planted in all the })lats May 

 11. First quality potatoes, " Beauty of Hebron," raised in 

 Vermont, were used as seed. The growth looked w^ell upon 

 all the plats until July 28, w^hen the vines on Plats 2 and 

 3 began to turn yellow. They commenced drying up Aug. 

 9, and by Aug. 12 were dry on all plats. An examination 

 of the little potatoes, July 1, showed already, in every case, 

 the marks of scab. 



The entire crop, when harvested, was so seriously affected 

 hy scab that it proved worthless in the general market. 



The months of July and August were exceptionally wet 

 and warm in our part of the State, — a circumstance which 

 has, most likely, aggravated our trouble. The potato crop 

 this year has been extensively a failure, in our vicinity, 

 wherever low lands have been used for its cultivation. 



B. — Observations with Scabby Potatoes. 



These experiments were inaugurated in 188G, for the pur- 

 pose of inquiring into the circumstances which control the 

 development and the propagation of the scab on potatoes. 



1886. — The first year's work in this connection has been 

 confined to the task of observing the behavior of scabby 

 potatoes as seed potatoes, under some definite previous 

 treatment. To prevent a possible propagation of scab in 

 the new crop by infected seed potatoes, the following course 

 was adopted : Thoroughly scabby potatoes, obtained from 

 the previously described experimental plats, were treated 

 with some substances known to be destructive to various 

 forms of parasitic growth. This operation was carried out 

 with the intention of destroying the propagating power of 

 adherent germs of an objectionable character, before plant- 

 ing the seed. 



The field for the observation was distinctly separate from 

 other experimental plats for the cultivation of potatoes. It 

 had been used for many years previous for the raising of 

 grass, and had since been planted but once, — the preceding 

 year (1885), with corn. The land was prepared by plough- 

 ing and harrowing in the same way as other potato fields. 



