350 



UXPEBIMENTS WITH PLANTS 



20y. How one-sided development of branches affects tlie 

 trunk. (See Tig, 202). 



rank vegetative growth and imparts a deep green to 

 the leaves, while phosphorus especially promotes the 

 production of flowers and fruit. It is a well-known fact 



that starving 

 a plant makes 

 it flower and 

 fruit much 

 earlier. De- 

 priving it of 

 water has the 

 same effect 

 (seepage 318). 

 An excess 

 of a particular 

 substance in the soil may render it unfit for some 

 plants, while others flourish in it. Thus, Asparagus 

 will stand so much salt that the weeds in an Aspara- 

 gus bed may be killed by sprinkling on salt, while the 

 Asparagus itself is not injured. 



Soil too alkaline for ordinary crops will raise Sugar 

 Beets and Alfalfa, while land too alkaline for these 

 crops will grow Salt Bush, which makes good fodder. 



Peat Moss or Sphagnum is killed bj^ a small 

 amount of lime, while other Mosses flourish on lime- 

 stone rocks and in water containing large quantities 

 of dissolved lime. The presence or absence of lime 

 usually has a marked effect on the flora. Some plants 

 are known as lime loving, others as the reverse, 



