PLANTS AND LIGHT 33 



be expected from plants that receive less light than they 

 need. 



Amount of Light Needed. The amount of light needed 

 depends on the kind of plant All of our cultivated 

 plants are descended from uncultivated plants, and re- 

 tain most of the characteristics of their wild ancestors. 

 Some of them demand all the sunlight possible. Among 

 these are the coconut and the plants of the grass family, 

 such as rice, maize, and cane. Other plants grew in 

 forests when they were wild plants, and do not usually 

 thrive in very strong light. The reason for this is that 

 their leaves, being large, cannot always be supplied with 

 water; therefore, in dry or windy weather they become 

 injured by dryness. Plants of this kind must usually be 

 protected by shade trees. 



Shade-loving Crops. The principal shade-loving crops 

 of the Philippines are abaca, cacao, and coffee. It is only 

 during the dry season, however, that too much light can 

 injure these plants, and in places where there is no dry 

 season they ought not to be shaded. In such places 

 they are more productive, because they receive more 

 light, and so can grow faster and stronger. In some 

 parts of Mindanao, abaca produces a good crop when 

 eighteen months old, and yields iS piculs of fiber a year 

 from one thousand plants. In places where abaca must 

 be shaded, two years is an early yield, and i 2 piculs a 

 very satisfactory product. Coffee needs to be shaded 

 in Batangas, but not in the highlands of Hcnguet and 

 Lepanto. 



