The fertilizers may be grouped into the class, easily soluble and pro- 

 ducing almost immediate injury; a second, moderately soluble and pro- 

 ducing delayed injury; and a third, difficultly soluble and producing no 

 apparent injury. On days of continuous sunlight a more or less pro- 

 nounced softness of tissue could be detected by careful observation long 

 before characteristic injuries became apparent. 



Effects of Overfeeding with Ammonium Sulfate. — A marked softness 

 of tissue was the earliest sign of overfeeding with ammonium sulfate. 

 A complete plasmolysis took place in that portion of the stem located 

 two and three nodes below the bud and in the portion of the stem just 

 above the node, so that the stem bent completely over. The shoots first 

 affected were those with buds one-half to three-quarters developed. At 

 the same time white spots 0.25 and i.oo mm. in diameter appeared upon 

 the upper leaves of these and the younger shoots. Microscopic examina- 

 tion of these showed the chlorophyll bearing tissue entirely plasmolyzed. 



In contrast to the injury from other fertilizers, practically every flower 

 split.* This splitting was not caused by the pressing outward of the 

 petals as is usually the case, but by a weakening of the tissue at the line 

 joining the sepals to form the calyx cup. Later stages resulted in the 

 drying up of the leaf tips, and the appearance of the white depressions 

 upon the older leaves. The sepal tips very early became brown. Later, 

 pustule-like elevations about i mm. across appeared on them, caused 

 by a crystal of ammonium sulfate beneath the epidermis. The injury 

 from excess of ammonium sulfate was more rapid and pronounced in the 

 presence of lime than without it. 



Effect of Overfeeding with Sodium Nitrate. — Injury followed heavy 

 applications of sodium nitrate within a few days, the characteristic 

 symptom being an even lightening of color of the foliage over the plant, 

 followed by drying of leaf tips and petals and withering of the plant. 



Effects from Large Applications of Sodium Chloride.**— The first appear- 

 ance of injury from large amounts of sodium chloride was two days after 

 its application, a plasmolysis of the cells of the stem, causing it to lose its 

 rigidity at the crown. When held within supports the plants appeared 

 normal. Gradually, however, the plants lost their turgidity and the 

 chlorophyll disappeared evenly throughout the entire plant. Tests made 

 in the spring of 19 15 with heavy applications of sodium chloride and 

 potassium chloride (12 kg. per 100 sq. ft.) showed the same effect from 

 each of them, while sodium sulfate, like potassium sulfate, showed less 

 injury and that only after a longer period. 



* Splits is a trade term denoting flowers with split calyces. 

 ** Sodium chloride, while not strictly a fertilizer, was used in the experiments be- 

 cause of its presence in considerable amounts in kainite and in some grades of com- 

 mercial potassium sulfate. 



