HORTICULTURE. 



757 



lizer reqiiireinenta of the wheat plant at different stages of growth are at variance 

 witli those of Liebscher on this subject. In these experiments it was found that 

 wheat which had formed hardly 2 per cent of the dry matter of the mature plant in 

 the fall had, at this time, taken up only irom 2.8 to 3.3 per cent of the nitrogen and 

 potash and 7.3 per cent of the phosphoric acid given in the fertilizer application. 

 From the beginning of June an energetic assimilation of the plant-food elements took 

 place, the quantities of the different elements taken up being about equal. After 

 blossoming, when the leaves begin to wither, assimilation decreases, and this is 

 especially noticeable in the quantities of potash and lime used by the plant at this 

 stage. Wheat requires abundant soil fertility for the isroduction of large crops, but 

 a good strong soil gives better results than the use of a heavy apj^lication of easily 

 soluble fertilizers. Eye differs from wheat in that it takes up a comparatively large 

 proportion of the necessary plant food in the fall. It is, therefore, more Ijenefited 

 by heavy applications of fertilizers than wheat and also because it is generally grown 

 on poorer soils. — f. w. woll. 



Production of economic plants in the Desert of Sahara, E. DUrkop {Inaug. 

 Diss., Univ. Jena, 1902, pp. 57). — This dissertation contains a general description of 

 the Desert of Sahara, together with more detailed discussions of the regions produc- 

 ing rubber, dates, senna, fibers, and colocynths. 



Statistics of field corps {Twelfth Census United States, Census Bpts., vol. 6 {Agri- 

 culture, pt. ;.^), ]iii. 1-275, 401-594). — General statistical and historical summaries 

 concerning the culture of the different crops are given with tables presenting the 

 figures for the different States in detail. The following table is a summary of this 

 information: 



Acreage, quantity, and value of farm crojjs in the United States in 1899. 



HORTICULTURE. 



Problems in orchard pollination, G. O. Greene {Industrialist, 29 {1902), No. 

 11, ]>]}. 163- 17S, figs. 5). — The causes of failure of apple blossoms to set fruit are dis- 

 cussed by the author under the following heads: The trees or the blossoms may be 

 injured by drought; they may lack nourishment or receive an excess of certain 



