CHAPTER TX 
INSECT ENEMIES AND DISEASES 
123. Importance of controlling garden pests. — The an 
nual loss in the United States to vegetable crops from 
the depredations of insects and diseases amounts to mil- 
lions of dollars. Practical growers, economic entomolo- 
gists and plant pathologists believe that most of the 
losses could be forestalled by taking the proper preven- 
tive measures. In too many instances, however, the 
grower makes no preparation for control and when the 
pests appear it is impossible to secure a spraying outfit 
and materials before great damage has been done. 
124. Preventive measures. — In the control of fungous 
diseases and insect pests of the garden, preventive meas- 
ures are of prime importance. Spraying is often neces- 
sary, but it is expensive and should not be employed 
ordinarily until all other practical means of prevention 
have failed. Single cropping or the want of proper rota- 
tion frequently causes trouble. When a crop pays un- 
usually well, the temptation is to continue its cultivation 
upon the same ground for years — a practice which har- 
bors insects and diseases. 
Diseased or infested seed or stock often introduce 
enemies. This is a strong argument in favor of the home 
production of seeds and plants. When plants are kept 
in a thrifty condition there is reduced danger of serious 
loss from both insects and diseases. Judicious fertilizing, 
cultivating and watering may be worth far more in ward- 
ing oft’ attacks than any amount of spraying. Infested 
soils when used in starting plants become a source of con- 
tamination. Too much care cannot be exercised in the 
selection of soil known to be free from disease germs* 
