156 EXPERIMENT STATION. [Jan. 



cells in the vicinity of the blisters, however, indicated that they 

 had been greatly stimulated. This had resulted in excessive cell 

 division, causing rupturing and a ragged, wounded appearance 

 of the tissue. An experiment with perfectly healthy lilies was 

 made, in which the plants were liberally fertilized with Chili 

 saltpeter, and in a short time we obtained practically the same 

 characteristics, that is, the blisters or eruptions. Blisters de- 

 veloped on a cyclamen were also observed, and were shown to be 

 due to an excessive use of nitrate of soda. 



Many cases of injury from overwatering and forcing have 

 come to our attention in connection with such plants as carna- 

 tions, tomatoes, etc. 



The effects of nitrates on plants have long been known, and 

 instances are mentioned by Czapek. Cases have been brought to 

 our attention several times where tomato plants have been af- 

 fected by the excessive use of fertilizers, and tests of the foliage 

 for nitrates revealed an excess in the leaves. The tomato leaves 

 in such cases had a curled and crinkled appearance, caused by 

 the contorted vascular bundles or veins. A somewhat similar 

 contortion of the foliage has been observed by us in soy beans 

 when grown under certain conditions. These symptoms have 

 been occasionally found in the field as well as in plants growing 

 in pots in the greenhouse, and analyses have revealed an excess 

 of nitrates in the foliage. 



Greenhouse cucumbers are more susceptible to injury from 

 manures and fertilizers than any crop known to us, and produce 

 more cases of malnutrition than any of the others grown under 

 glass. The condition of the soil which will destroy a crop of 

 cucumbers will nut, however, affect lettuce or tomato plants, 

 while a rose or carnation plant might appear underfed in such 

 a soil. 



Erom a long experience in growing cucumbers under glass, 

 as well as years of experimenting with this crop, and annual 

 observations on a lar2;e nundier of commercial houses in the 

 State, we are convinced that it is not safe for the ordinary 

 grower to apply commercial fertilizers to a crop of this kind. 

 Commercial fertilizers undoubtedly could be used on cucumbers, 

 but would have to be used very sparingly, and only with the 

 advice of the expert. 



