?t24: KEirOItT OF TUB HOUTICULTUUAL DEPARTMENT OF THE 



almost wholly conliiicd to Americnn agricultural experiment 

 stations. The mo'st important results of these investigations are 

 summarized in the following paragraphs. Mr. F. H. Hall has 

 kindly assisted in preparing this summary. 



In experiments in 1888-9 by Maynard,^ on lettuce under glass, 

 muriate and sulphate of potash, nitrate of soda, sulphate of 

 ammonia and dissolved bone black were used on two crops; the 

 same fertilizers and nitrate of potash on a third crop. These 

 were applied dissolved in water, but the amounts used and the 

 character of the soil are not stated. Mildew affected all plats, 

 the nitrate of soda plat worst. 



Sulphate of ammonia gave the best lettuce with two crops, 

 but a decidedly inferior product for the third crop. Nitrate of 

 soda, and both muriate and sulphate of potash were of no bene- 

 fit; even apparently injurious in some crops, the results with 

 sulphate being quite unfavorable. Bone black gave conflicting 

 results. The single test with nitrate of potash showed apparent 

 benefit. 



In 1892 Green^ applied various nitrogenous fertilizers to let- 

 tuce and other greenhouse crops on a rich compost, using double 

 the amount applied in outdoor work. No benefit was obtained, 

 thus showing that the limitations of these fertilizers, so far as 

 stimulating plant growth on such soil is concerned, are narrower 

 than some had supposed. 



In 1892-3 Groessmann^ grew lettuce under glass on a sandy 

 loam very low in humus and fertilizing ingredients. Commer- 

 cial fertilizers and chemicals w^ere used in various combinations, 

 each box receiving the same amount of nitrogen, potash amd 

 phosphoric acid, the last always in dissolved bone black. 



Maynard's results with muriate of potash were confirmed by 

 the strikingly unfavorable influence shown by it in these tests; 

 but, contrary to his experTence, potash in the simple sulphate 

 or the magnesia suli^hate gave the most satisfactory growth. 



= Maynarcl, S. T. Mass. Hatch Sta. Bui. 10:1-5 (1890). 



* Green, W. J. Ohio Sta. Bui. 43:100, 101. 



^Goessraann, C. A. Mass. State Sta. Ann. Rcpt. 1893:241-201. 



