Mar. 3o, 1916 Relation of Green Manures to Failure of Seedlings 
1163 
The average percentage of germination in duplicate pots, after one and 
two weeks, is recorded in Table II. The last column gives the relation 
between the treated and untreated seeds. A glance at the figures shows 
clearly that buckwheat, com, and sunflower were not injured by green 
manures. On the other hand, hemp and mustard were seriously injured; 
the latter showed the greatest loss. Lupines are not so sensitive as 
mustard or hemp toward green manure, although a slight decrease in 
germination is noted. 
As regards fat content, it will be seen that with the exception of sun¬ 
flower those seeds rich in oil are the most sensitive to green manuring. 
The very quick germination of sunflower seed may explain their resistance 
to the injurious factor. 
Table III presents data to show the striking difference in behavior of 
fat and starch seeds toward green manures. A comparison of the injury 
resulting from the use of green clover and green oats is made. 
Table III .—Effect of green clover and oats on the germination of cottonseed and wheat 
No. 
Seed. 
Treatment. 
Germination. 
1 week. 
1 
2 weeks. 
3 weeks. 
Relative. 
x 
Cotton. 
None. 
Per cent. 
8S 
45 
Per cent. 
9 2 * 5 
65 
Per cent. 
92. 5 
65 
Per cent. 
IOO 
2 
1 per cent of oats. 
70 
3 
A 
.do. 
Wheat. 
1 per cent of clover.. 
None. 
17-5 
95 
85 
* 7 - 5 
100 
17* 5 
100 
19 
IOO 
5 
1 per cent of oats. 
90 
90 
90 
6 
.do. 
1 per cent of clover.. 
85 
85 
85 
85 
The germination of cotton was seriously injured by the presence of 
green manures; the green clover was much more harmful than oat 
tissue. Wheat was little affected by the use of green manure. The 
data confirm the results of the preceding test—that is, that seeds rich in 
oil are especially sensitive to green manures. It appears that the per¬ 
centage of injury depends to a certain degree on the source of the plant 
tissue. Plate LXXXIII, figure 1, is reproduced from a photograph of 
cotton seedlings two weeks after planting. In order to make the seed¬ 
lings more visible, a thin layer of white quartz sand was poured upon the 
surface of the soil. 
With soybeans in place of wheat, this experiment was repeated, as 
shown in Table IV. 
