Biology Reference
In-Depth Information
Mixing The Chemicals
It still seems incredible that so many gardeners
continue to treat their plants in a haphazard
fashion. Buy a set of measuring spoons and
a measuring cup, marked in ounces. Buy a large
pail and mark it off in gallons. Then measure,
exactly!
Dosage directions are usually given in pounds
per 100 gallons of water, with or without transla-
tion on the label into small amounts. Not much
arithmetic is required to figure a smaller dosage,
if you remember a few measurements:
Conversion table
scales. It also works out at about 1 level tablespoon
of the Dithane powder per gallon, and it is easier to
measure than to weigh. There is, however, a good
deal of volume variation, depending on how
fluffed up the material is at the time you measure
it; so weighing is preferable.
When you buy chemicals in small packages
designed for the home garden, the dosages
given on the labels will probably be in terms
of tablespoons per gallon, and you need only
follow directions. When, to save a good deal of
expense, you buy the larger sizes intended for
farmers, the directions may be given only in
terms of pounds per 100 gallons. As a very
rough rule of thumb, you can figure 1 table-
spoon per gallon where directions call for 1
pound per 100 gallons, but the different mix-
tures have different weights so this is not very
accurate.
At the rate of 1 pound to 100 you would use,
accurately, 3/4 T captan 50 %, 1 T chloranil
(Spergon), 1/3 T copper sulfate, 2/3 T dichlone
50 % (Phygon), 1 1/4 T ferbam, 1/2 T maneb,
1 T spray lime, 3/4 T thiram, 1/2 T sulfur,
2/3 T zineb (Dithane Z-78 or Parzate), 1 1/4 T
ziram to 1 gallon of water.
Sometimes materials for soil treatment are
given in pounds per acre. Knowing that one
acre contains 43,560 square feet, you can
make a proportion to find out how many pounds
are required per 1,000 square feet.
3 teaspoons
1 tablespoon
¼
2 tablespoons
¼
1 fluid ounce
16 tablespoons, 8 fluid ounces
¼
1 cup
16 ounces, 2 cups
¼
1 pint
2 pints, 4 cups
1 quart
¼
16 cups, 8 pints
4 quarts
1 gallon
¼
¼
1 acre
43,560 square feet
¼
Suppose 3 gallons of a 2 to 100 dilution of lime
sulfur is desired. That is the same as a 1 to 50
dilution. Three gallons constitute 48 cups; so if 1
cup of liquid lime sulfur is added to 3 gallons, you
will have a 1 to 49 dilution, and that is close
enough.
Or suppose you want to make 4 gallons of
Zineb at the rate of 1 1/2 pounds per 100 gallons.
That is 24 ounces per 100 gallons, or .24 ounce for
1 gallon and .96 ounce for 4 gallons. That is
approximately 1 ounce to weigh on your small
