THE VARIOUS CROP OR CULTURE PLANTS 271 



Another way to produce new varieties is by hy- 

 bridization or crossing, that is, fertilizing one kind of 

 plant with the pollen of another. From the seed so 

 produced we often get some seedlings showing a new 

 or advantageous combination of the two kinds crossed 

 (see Chapter IX). 



Varieties must be adapted to climates and soils. How- 

 ever good a crop or fruit variety may be, it may not do 

 well in some particular climates and soils. The best 

 varieties in the Atlantic or humid states may not suc- 

 ceed so well in arid California. The wheat of Minne- 

 sota, the best in the United States, loses some of its 

 good qualities after growing for some years in Cali- 

 fornia, or eastern Oregon and Washington. Some of 

 the best Eastern fruits, first tried in California, have 

 now been replaced by varieties originated in California. 

 Our Riverside navel orange loses much of its quality 

 in Florida. The pecan and hickory nuts of the Missis- 

 sippi states do not produce well in California. 



We must therefore test crop varieties brought from 

 elsewhere before we plant them on a large scale. We 

 must inquire in what climates and soils they have done 

 well, and then compare these with our own. 



Crops for various purposes. Some field crops are 

 grown entirely (or chiefly) for their seeds, like wheat, 

 peas, and beans, but the stems and leaves of most 

 can be used also for cattle feed or other purposes. 

 Sometimes all these plants are grown only for their 



