Proceedings of Seventeenth Normal Institute 265 



If blighted potatoes are to be placed in storage they should not 

 be dug until the tops are dead and dry. By so doing the loss 

 from rot will be less than it would be if they were dug and stored 

 while the vines were yet partly green. This has been proven by 

 experiments made at the Vermont Station. Other experiments 

 at the Vermont Station have shown that it is of little use to 

 sprinkle air-slaked lime over potatoes in storage. It does not pre- 

 vent them from rotting. The best that can be done is to keep 

 the potatoes dry and cool and avoid deep piling. 



Leaf-roll and mosaic seem to be much more common and im- 

 portant than we have heretofore realized. Since these diseases 

 are transmitted through the seed it is important to avoid using 

 tubers from affected plants for seed. Leaf-roll is characterized 

 by an upward rolling of the leaves; mosaic, by wrinkling of 

 the leaves and their yellowish green color. The leaves of healthy 

 potato plants are large, flat, smooth and dark green. 



^Notwithstanding all that has been said and written on the sub- 

 ject it seems that many persons do not yet know the proper 

 method of using corrosive sublimate for the disinfection of seed 

 potatoes. The solution should be prepared by dissolving one 

 ounce of corrosive sublimate in a small quality of hot water and 

 then diluting to seven and one-half gallons. Since corrosive 

 sublimate rapidly corrodes metals it should not be used in metal 

 containers. Use wooden or eathenware vessels. Soak the tubers 

 in the solution one and one-half hours and spread them out to 

 dry. With repeated use the solution loses strength ; hence, after it 

 has been used three or four times, it should be discarded and a 

 new lot prepared. If it is desired to treat for Rhizoctonia as 

 well as for scab, corrosive sublimate is preferable to formaldehyde, 

 for the reason that corrosive sublimate is more effective against 

 Rhizoctonia. It is also more effective against powdery scab. 



