§wJif 'J flu^ . (U.L c^r. 
V Hvk H 
£> Stock Solution A. 
In -g- gallon of water are simultaneously dissolved 3*2 grams 
(l teaspoonful) each of boric acid (H^BO^), manganese sul¬ 
phate (MnSOj^.Tf^O) and zinc sulphate {ZtiSOl . THgO). To this 
solution % teaspoonful of copper sulphate (CUSO 4 . 5 H 2 0 ) 
then added if desired. Stock Solution A may be added to 
culture solutions (see later) at any time before use. 
Stock Solution B. 
Dissolve 0.8 gram (1 teaspoonful) of iron (ferric) chloride 
(PeCl 3 ) or nitrate (FeCNO^)^) in 1 pint of water. Ferrous 
sulphate (FeSO^.THgO) may be used as a source of iron but has 
a greater tendency to precipitate from solution before use. 
Ferric citrate, though it dissolves slowly, remains in solution 
much better than does the sulphate. As iron has a tendency to 
precipitate in contact with culture solutions, Stock Solution B 
should only be added immediately before use with plants. 
In using any of the culture solutions described hereinafter, 
Stock Solution A may be added in the proportion of 10 cc. (2 
teaspoonfuls) to each 3 gallons of culture solution if pure 
chemicals are used, or in the proportion of 3 cc. (l teaspoonful) 
to each 5 gallons of culture solution if commercial-grade 
chemicals are employed in preparing the latter. 
Stock Solution B should be added to culture solutions just 
before actual use in the proportion of 20 cc. (4 teaspoonfuls) 
of B to each 1 gallon of the culture mixture. 
Under certain conditions (bright days) iron may be used up 
very fast by plants. Therefore, if any signs of iron chlorosis 
(see Chapter Seven) appear, additional iron should thereupon be 
added, 
FORMULA I. - Fertilizing Salts for Culture Solution, 
Recommended and Used by the N.J. Agricultural Experiment Station, 
r 
--.-Fertilizing Sa 
It 
. 
Monopotassium Calcium 
Magnesium 
Ammonium 
Sulphate 
Unit of 
Phosphate 
Nitrate 
SuInhate 
(nh^) 2 so, 
Measure 
kh 2 po^ 
Ca(N0p2.4H 
2 0 MgS0^.7H 2 0 
Grams per 3 gal- 
Ions of solution 
5.9 
20.1 
10,7 
1.8 
Teaspoonfuls per 
3 gallons of 
solution (ap¬ 
proximate 
1 4. 
k 
2i 
1 
Each of these chemical salts is dissolved separately in about 
a pint or quart of water, their solutions mixed, and then diluted 
with water to 5 gallons. For trace elements, Stock SolutioreA and 
B are added as directed. 
The inclusion of ammonium sulphate in Formula I is stated to 
be beneficial in maintaining the pH value of the solution within 
a smaller range during the life of the solution. 
