Ano-ewandte Botanik. 589 



& 



Sinslebener Hafer recht wichtig. Sonst werden die Sorten, welche 

 geprüft wurden, beschrieben und ihre Entstehung erläutert, u.zw. 

 auch Sommerweizen, Feldbohnen und -Erbsen, Futter- und Zucker- 

 rüben. Matouschek (Wien). 



Piper, C. V., Fundamental principles in agronomy. ( Journ . 

 Amer. Soc. Agronom3\ VI. p. 227—241. 1914.) 



Contains the following theses: Every crop plant has a definite 

 ränge of adaptations or reactions as regards climate and soil; Tillage 

 tends to increase yields; Shallow tillage conserves soil moisture; 

 Rate of seeding or distance of spacing affects yield ; Depth of planting 

 affects stand and therefore m'dy affect 5neld; Time of seeding affects 

 yield; Quality of seed affects 3neld; Rotative cropping tends to 

 mcrease or to raaintain yields. while Single cropping tends to reduce 

 yields; Mixed seedings tend to increase yields; Fertilizers tend to 

 increase yields; The nitrogen content of the soil is most cheaply 

 maintained by keeping up the supply of humus, and especiall}'- by 

 growing legumes which alone of crop plants can utilize atmospheric 

 nitrogen; Productivity is approximately maintained by feeding crops 

 to animals and returning the manure to the soil; Selecting the best 

 plants tends to improve the breed; Hybridization tends to stimulate 

 vigor; Plants introduced from their original to a new and similar 

 environment often tend to become aggressive; Thinning buds by 

 pruning or otherwise tends to increase the size of the remaining 

 resultant tlowers and fruits; Vegetative vigor and reproductive vigor 

 are mutually antagonistic; and Dwarfing of perennial plants may 

 be secured by budding or grafting on Stocks not whoUy congenial. 



Treleale. 



Swingle, W. T., New citrous fruits. (Amer. Breeders Mag. 

 IV. p. 83—95. 1913.) 



The author describes briefly his results, got in 1897 in making 

 new C//rws-hybrids between common oranges and the hardy Chinese 

 Citrus trifoliata. Especialij^ good forms among these "citranges" are 

 the iVIorton, Colman, Savage, Rusk and Cunningham; the 

 Willits citrange is interesting for its tendency to freakishness in 

 shape. Beginning in 1909 the writer undertook the breeding of hard}- 

 citrous fruits on a very large scale and as a result some thousands 

 of hybrids, containing more or less blood of Citrus trifoliata, are 

 now growing in various parts of the southern U. S. A. In the same 

 year 1897 another hybrid was made by the writer between the 

 tangerine orange and the grapefruit; this hybrid, called "Tangelo". 

 constitutes an important source of new and important citrous fruits 

 for commercial use. Another new type of citrous fruit is the "lime- 

 quat", which the writer originated in 1909 b}^ crossing the common 

 West Indian lime with the kumquat orange, one ot the hardiest of 

 the evergreen citrous fruits. 



The work done hitherto is merely of a preliminary order and 

 of comparatively little importance, but the writer expresses the hope, 

 to get better and greater results by further crossings. He has intro- 

 duced for this reason some wild relatives of the cultivated oranges, 

 for instance the "desert lemon" of the Australian desert {Atalantia 

 glauca (Lindl.) Benth.) found growing in a region with very low 

 temperatures (occasional}' zero Fahrenheit) and "cherry oranges" 



