Apr. 3, 1916 Relation of Carbon Bisulphid to Plant Growth 



15 



In addition to the soluble plant food, half of the jars received 2 per 

 cent of carbon bisulphid. After treatment the jars were held for two 

 months before planting to buckwheat and oats. The results of the test 

 are given in Table XIV. 



Table XIV. — Effect of carbon bisulphid on the growth of buckwheat and oats in silica 



sand 



It is apparent from the data that carbon bisulphid in silica sand exerts 

 a beneficial effect on the growth of both buckwheat and oats. This 

 agrees with the results of Koch (6) — that carbon bisulphid stimulates 

 the higher plant growth. Although the duplicate jars do not agree very 

 closely, the highest yield of the control was lower than any of the treated 

 groups. For some unexplainable reason, the oats in jar 3 failed to grow. 

 The young seedling died soon after germination. Plate II, figure 3, is a 

 reproduction of a photograph of the buckwheat series. 



CLOVER, BUCKWHEAT, AND MUSTARD 



The foregoing experiment was repeated, using 3-kgm. jars and Tollen's 

 medium. Only i per cent of carbon bisulphid was added. The jars 

 were planted 30 days after treatment. The yields of the different crops 

 are presented in Table XV. From the beginning clover and mustard 

 began to show the favorable effect of carbon bisulphid. 



Table XV. — Effect of carbon bisulphid on the growth of buckwheat, clover, and mustard 



in silica sand 



As compared with the results shown in Table XIV, the increase in the 

 growth of buckwheat with carbon bisulphid was much smaller. The 

 clover crop was about doubled in the presence of carbon bisulphid. Mus- 



