Reproduction in Relation to Agriculture 219 



Bureau of Science, P. /. 



FIG. 135. Sugar-cane cuttings. The plants are started in the fields 

 from cuttings and not from seeds. 



onion are examples of crop plants started in this way. Gera- 

 niums, coleus, willows, currants, grapes, and most ornamental 

 shrubs are grown from cuttings. These cuttings are pieces 

 of stem containing two or more nodes. Propagation by 

 bulbs, conns, or rootstocks is the method commonly employed 

 in starting lilies, tulips, hyacinths, irises, cannas, Caladiums, 

 and chrysanthemums. Many of our fruit trees are multi- 

 plied by budding and grafting, which are specialized forms 

 of vegetative propagation (page 132). 



Vegetative propagation has been found advantageous in 

 crop plants wherever its use is possible, (i) because the vari- 

 ability of the plants produced is much less than when they are 

 propagated by seeds, (2) because some plants, like the sugar 

 cane, banana, and horseradish, do not produce seed, and (3) be- 

 cause it saves time in securing the product, as a longer period 

 is required for the maturing of plants started from seeds. In 

 practical plant production, vegetative multiplication is as 

 important as reproduction by seeds. 



