7 McMINNV ILLE, TENNESSEE , 43 
To ascertain number of plants required per acre, 
divide the number of square feet in an acre (43,560) 
by the number of square feet to be given each plant. 
For instance, apple, 35 x 35 feet, requires 1,225 
square feet per tree or 35 trees per acre. 
CONTROL OF INSECTS AND DISEASE 
-.- With the passing of each year, the necessity for 
spraying for insects and diseases which do damage 
to trees and plants becomes apparent, and while it 
is not always possible for the homeowner to iden- 
tify certain insects and diseases, there are many 
which are very common and which are easily con- 
trolled. Where identification is not possible, sam- 
ples may be sent to your state entomologist, where 
dependable advice will be gladly given. As sug- 
gested above, many of the common insects and dis- 
eases may be easily controlled by the home planter 
if he will take the trouble to equip himself with 
simple spray pumps and common insecticides for 
spraying, and with a few simple tools with which 
to do proper pruning. This material can usually 
be purchased from your local dealers or merchants 
or can be ordered from various dependable sources. 
Insects are usually divided into two classes, the 
“biting and chewing” and “sucking” insects... The. 
first may be controlled with poison when it is pos- 
sible to so spray that the poison will be eaten, while 
the other can be controlled by what is termed con- 
tact sprays. 
Diseases are usually caused by a fungus growth 
and are controlled by sprays known as fungicides. 
A few of the diseases, such as blight in pear, etc., 
are caused by bacteria, and where such diseases 
occur, one of the best remedies is to cut away the 
infected parts, destroying the prunings by burning. 
Therefore, there are two general classes of sprays, 
insecticides and fungicides, and the insecticides 
being divided into two classes known as poison and 
contact insecticides. Arsenate of Lead is a good 
example of the poison insecticide, while Lime-Sul- 
phur Solution is a good example of the contact 
insecticide, with Bordeaux Mixture being the old 
stand-by as a fungicide. 
SPRAY FORMULAS 
. Arsenate of Lead. One of the most common and 
most valuable poison sprays; may be prepared at 
home, using either powder or paste, it being easily 
procured in either form. Use at the rate of 2% 
pounds of the paste or 2 pounds of powder to 50 
gallons of water. Use for the control of flea beetle 
on grape, caterpillar on pecan, biting and chewing 
insects on shade trees, shrubs, etc., and for tent 
caterpillar on evergreens. Also use as spray for 
curculio and codling moth on fruit trees. 
