TUBER CROP PROJECTS 201 



evidenced by the eyes, which are rudimentary buds. True roots do 

 not have buds. Sometimes tubers form in the axils of the leaves 

 above ground, and only stems or shoots could grow in such a 

 location. The formation of tubers above ground is usually an 

 indication of the presence of a fungous disease, but it is a proof 

 of the true nature of the tuber. 



The stems which bear the leaves are of the ordinary kind and 

 are usually smooth at first, but they develop ribs as they grow 

 older. The leaves may be simple when first developed, but they 

 become compound. The leaves of the different varieties vary con- 

 siderably in appearance. The flowers of the potato are regular 

 and vary from white to yellow, purple, or blue. Some varieties 

 seldom bloom and even when flowers are produced the fruits are 

 only rarely developed. The fruit is a globoid berry resembling 

 a very small tomato,' and is called by different names, the most 

 common being " potato ball " or " seed ball." The seeds are 

 small and numerous. Potatoes are rarely propagated by seed 

 except by plant breeders who desire to cross or improve varie- 

 ties. Every one is familiar with the common method of prop- 

 agation by tubers. We are so accustomed to propagating 

 plants by seed that the expressions " seed tubers " or " seed 

 potatoes " are only natural, but we must keep in mind that the 

 tubers are not seeds. 



1. Where was the potato first cultivated? 



2. Under what conditions does the potato thrive best? 



3. What part of a plant is a tuber ? 



4. What is the nature of a healthy potato leaf? 



•3. What conditions of the leaves indicate diseases? 



