20 BREEDING 



to the air and light, and in no way can stray pollen fall upon 

 the blooms. The proper time for pollination is about the 

 second or third day of bloom. The pollination is repeated 

 for two successive days ; that is, if the pistil has not fallen. 

 The cheese cloth should be left on for about five or six days. 

 When the fruits are thoroughly ripe they are gathered, 

 seeds squeezed out, washed in a cheese-cloth bag, and al- 

 lowed to dry. 



It is always a wise plan to select strong parent plants, 

 because they develop larger and better seed. These seed 

 in turn develop larger potatoes the first year from the seed 

 than those from a delicate plant. It is of greater import- 

 ance that the mother plant be strong than the male plant, 

 and care should be taken in selecting the most vigorous ones. 



This is a fact not known by most potato experts, if any. 

 The way of determining the actual fertility of the potato 

 fruits or seed balls without the aid of a magnifying glass: 

 The balls are partially or wholly covered with small, white 

 pimples. The smooth fruits are rarely, if ever, good. 



I have, in selecting crosses, chosen those with about 

 the same qualities, with the idea of improving them; while 

 at other times I have crossed the opposites, with the idea 

 of obtaining different and better qualities. These ideas are 

 both good, providing the crosses used possess favorable 

 points. I have noticed that the potatoes not seemingly 

 closely related have greater affinity for one another than 

 those which are apparently related. 



I would not advise the potato breeder to use too much 

 fertilizer on the first-year seedlings. This policy is followed 

 by some, but is not a wise plan. The potato vines generally 

 grow rank and scarcely any tubers are to be found. Some 

 breeders use food material to induce variation, but the pota- 

 to naturally tends to vary even if crosses within a variety 



