1918.1 FIELD CROPS. 529 



between the eleventh and twenty-fifth days of growth. Nitrogen accumulation 

 appeared to be in direct proportion to an excess of phosphoric acid and lime, 

 while excess potash gave distinctly inferior results except in the very early 

 seedling stages. 



Nodules first appeared on Phaseolus mungo radiatus when the seedlings 

 were about 10 days old. With an excess of potash and lime small nodules 

 formed largely on the primary roots but extended throughout the root system 

 as the plant approached the flowering stage. An excess of lime encouraged 

 nitrogen fixation and nodule development particularly, while similar results 

 wei'e obtained with an excess of phosphoric acid. 



Plants producing fibers analogous to that of kapok, F. Michotte {Compt. 

 Rend. Acad. Agr. France, 3 {1917), No. 17, pp. 489-493).— The author lists 38 

 species, under 13 families, the fibers of which are somewhat analogous to that 

 of kapok, indicating the habitat of each and its particular use. 



Marine fiber, D. C. Wintekbottom {So. Aust. Dept. Chem. Bui. 4 {1917), 

 pp. 86, pis. 17, fig. 1). — Marine fiber, consisting of the fibrous remains of the 

 sea plant Posidonia australis, is said to occur in immense deposits in the 

 shallow coastal water of Spencer and St. Vincent Gulfs, Australia. Detailed 

 descriptions are given of the plant and fiber and of the operations of the three 

 commercial firms occupied in raising and cleaning the fiber. The principal uses 

 of the product include the insulation of steam and refrigerating plants, house 

 cooling, and the manufacture of bedding. Fair qualities of paper have been 

 made from the fiber, and its use by the textile trade is being advocated. The 

 cost of production is estimated at approximately $81.57 per ton delivered at a 

 European port. The market value of the fiber is approximately $110 per ton. 



The identity of fiber Agaves, L. H. Dewey {West Indian Bui. 16 {1917), 

 No. 2, pp. 104-111). — In a paper presented before the Fiber Congress held at 

 Surabaya in July, 1911, and here published for the first time, the author 

 briefly describes the 16 principal species of Agave producing commercial fibers, 

 together with synonyms and references to other names which are confused with 

 fiber-pi'oducing plants. 



A key to the Sisalanae in the West Indies, with brief descriptions of A. four- 

 croydes and A. sisalana, is reproduced from the work of Trelease, previously 

 noted (E. S. R., 30, p. 526). 



Alfalfa management, B. F. Sheehan {loioa Agr., 18 {1917), No. S, pp. 114, 

 115, 129, 130, figs. 2). — Replies to inquiries made of a large number of Iowa 

 farmers by the Iowa Experiment Station regarding the production of alfalfa 

 have been compiled and analyzed. 



Reports from 367 individuals using a nurse crop showed an average yield of 

 3.9 tons of hay per acre, as compared with 3.6 tons reported by 603 who seeded 

 without a nurse crop. The failures reported amounted to 17.2 per cent without 

 a nurse crop and 23.4 per cent with a nurse crop. Cutting the nurse crop for 

 hay resulted in an average yield of 3.9 tons of alfalfa for 106 farmers, and 

 where the nurse crop was allowed to mature 3.2 tons. Failures were repoi'ted 

 by 10.3 per cent of those who cut the nurse crop for hay, while 21.4 per cent . 

 reported failures when cutting the nurse crop for grain. An early-maturing 

 variety of oats, such as Kherson, seeded at the rate of 1.5 or 2 bu. per acre, is 

 recommended for use as a nurse crop. 



Attempts to thicken the stand by reseeding without plowing up the field were 

 most successful where the seed was drilled in. Cultivation to control crabgrass, 

 foxtail, or bluegrass was followed by average yields of 3.9 tons for 234 individ- 

 uals who employed disk harrows and 3.8 tons for 44 who used either spring- 

 tooth or spike-tooth harrows, while 653 farmers giving uo cultivation averaged 



