Plants as Affected by Insuffictent Light. 137 
grain sown too thickly on rich ground, that falls (lodges) 
before maturity. 
239. Too Close Planting Causes Deficient Light 
and all the resulting evils. Indian corn grown too thickly 
does not ear well, and is lacking in nutritive qualities; 
strawberry plants grown too closely do not fruit well, and 
the fruit lacks flavor and firmness; nursery trees grown too 
closely are slender-stemmed, deficient in foliage and have 
poorly-developed roots. A rule to govern distance in plant- 
ing has already been given (123). 
When a slender and flexible growth is desired, as in trees 
grown for hoop poles, or willows for wicker-work and tying, 
a certain amount of crowding is advisable. 
240. Weeds Cause Deficient Light in low-growing 
crops as strawberries, dwarf heans, potatoes etc., and also 
tend to rob the plants of food and moisture. They are, 
therefore, directly injurious. 
241, Plants Under Glass are Especially Liable to 
Suffer from Deficient Light, because the walls and sash 
bars of the structure necessarily intercept a considerable 
part of the solar rays. The roofs of glass houses should be 
formed of large lights of glass, with the smallest possible: 
sash bars, and the benches should be arranged to bring the 
plants as near to the glass as possible. 
942. The Electric Arc Light has been found useful 
as a supplement to the scanty sunlight of short, early-winter 
days, in forcing certain vegetables and flowers. 
943. Insufficient Pruning Prevents the formation of 
Fruit-Buds in orchard trees, by restricting light and thus 
9 
