CHAPTER XXII 
FAMILIAR FARM ENEMIES 
What Kinds of Enemies Have We?—If there were 
no weeds growing in our field, if there were no molds 
or rots to destroy our plants, if there were no destructive 
insects or bacteria, farming would certainly be a very 
desirable occupation. We would need only to sow and 
reap. Unfortunately, all of the plants and animals which 
we raise upon the farm have either visible or invisible 
enemies. Crops growing in the field may be completely 
destroyed by the attack of insects. Molds, blights and 
wilts may destroy our garden and fruit crops. Cotton 
boll weevil is one of the many enemies of our great 
southern crop. Corn smut and wheat rusts have caused 
great losses. Weeds of all kinds crowd out our more 
valuable food plants. Rats and mice destroy enormous 
amounts of grain each year. Very few of our useful cul¬ 
tivated plants can be mentioned, which do not have some 
enemy in the form of an insect, animal or plant. Many 
of these are not visible and a careful study must be made 
to gain even a limited knowledge of so many enemies. 
Weeds are those plants which grow where they are 
not wanted. Johnson grass might become a valuable 
pla<nt for hay, but it has a habit of living for several 
years in the soil, crowding out other useful plants. Dog 
fennel was once cultivated as a medicinal plant, but it is 
now generally considered a weed. Foxtail and crab 
grasses have been grown in England for centuries as for¬ 
age grasses. They never fail to harm the corn crop that 
270 
