ACTION OF ALPHA-CROTONIC ACID ON PLANTS 
Table 3 
Showing the influence of phosphate in overcoming the harmful efl^ect of a-crotonic acid. 
Green weight of wheat plants in nutrient solutions composed of CaH4 (P04)2, 
NaNOs, and K2SO4. Cultures arranged according to content of P2O5. 
Culture No. 
Parts ^er Million of 
Average Green Weight of Culture 
Percentage Decrease 
P2O5 in Nutrient 
Solution 
(See Fig. 2) 
Without Crotonic 
With 25 P. p.m. 
Due to Crotonic Acid 
Acid 
Crotonic Acid 
80 
grams 
grams 
I 
1. 10 
1. 00 
9 
2- 3 
72 
1-75 
1.32 
25 
4- 6 
64 
1.96 
1. 61 
18 
7-10 
56 
2.18 
1.73 
20 
11-15 
48 
2.46 
1-55 
25 
16-21 
40 
2.61 
1.87 
28 
22-28 
32 
3.20 
1.91 
40 
29-36 
24 
2.68 
2.02 
26 
37-45 
16 
3.10 
1.91 
40 
46-55 
8 
2.99 
1.88 
38 
56-66 
0 
2.66 
1.77 
34 
There is a reduction in growth of only 22 percent by the crotonic acid 
in the phosphate end of the triangle, a reduction of 30 percent in the nitrate 
end of the triangle, and a reduction of 39 percent in the potash end of the 
tirangle. 
Fig. 5. Wheat plants in triangle sets of nutrient salts, (i) With 25 p. p.m. a-crotonic 
acid, (2) without cc-crotonic acid. 
The two sets of cultures are shown in figure 5, the crotonic acid set on 
the left and the normal set, containing nutrient salts only, on the right. 
Several other experiments were planned so as to determine whether 
calcium or phosphate, or the salt as a whole, produced the antitoxic effect 
on the crotonic acid. These experiments were made by using sodium salts 
instead of calcium, and employing all three sodium salts of phosphoric acid, 
