395 



number, or not at all, while the branches continued growth. Here too, for 

 the most part, the fertilized plants died during the winter from Botrytis. 

 In other fertilization experiments, made with horn shavings on Ericas, 

 there was a luxuriant leaf development at the expense of the blossom buds, 

 but the fertilized plants, during the winter, showed no greater weakness. 



From the many instances which have come to my notice, I must state 

 the frequent "failure of forced Lilies-of-the-V alley," as due to an excessive 

 nitrogen fertilization. Chile saltpetre and ammonium sulfate are often 

 used when the plants are grown for two years out of doors. 



The plants grow more luxuriantly and their very strong (mostly blue- 

 tipped) "pips" (bud-cones) deceive the buyer; the formation of the in- 

 florescences., however, is weak. Such plants force with great difficulty and 

 frequently bear flower clusters in which some buds do not mature. Com- 

 parative experiments made by Koopmann^ showed very interesting differ- 

 •ences in forcing. When kainit was used as a fertilizer in growing the 

 plants, the flower clusters developed first and the leaves followed very 

 slowly, — on the other hand, when ammonia was used the leaf growth was 

 so luxuriant that the flower clusters were entirely hidden by the leaves. In 

 general, potassium may be recommended as a fertilizer for Lilies-of-the- 

 Valley. 



A further injurious effect could be determined for Roses. I have be- 

 fore me observations showing that tea roses, among others, Marechal Niel 

 and Nyphetos, grown indoors, drop their buds after heavy fertilization, or 

 decay at the point where the calyx passes over into the stem. When dis- 

 eased plants had been repotted in a sandy soil poor in nutrients, normal 

 blossoms developed in the following year. I observed similar phenomena 

 of deca}^ in Bourbon and Remontant roses in the open after sewage fertiliza- 

 tion. Here, an application of g}"psum gradually decreased the disease. 



In other garden plants, even in ivy, I had opportunity to observe phe- 

 nomena of decay after an excess of nitrogen (usually in the foi"m of sewage 

 fertilizers, liquid manure, Chile saltpetre and ammonium sulfate). In the 

 majority of cases, I have recommended transplanting the plants into pure 

 sand or a very sandy leaf loam for a year and have tried it myself repeatedly 

 with good results. 



Leaf Curl of the Potato. 



W^e will include here this disease so well-known to potato growers and 

 so often studied scientifically; the causes of which, however, are still un- 

 known. The reason for considering leaf curl here is the deduction from 

 my observations that diseased shoots show characteristic evidences of one- 

 sided nitrogen fertilization. Direct results are not involved here, only the 

 after effects in the following year. The parent tuber is either immature in 

 a few eyes, or entirely so. In the following year a diseased condition de- 

 velops in all of the shoots or only in some of them. This limitation of the 



1 Zeitschr. f. Pflanzenkrankh. 1894, p. 314. 



