1917] FIELD CROPS. 637 



Solanum commersonii, the swamp potato, Siebect (Illus. Landw. Ztg., SG 

 (1916), No. 17, pp. 110, 111, figs. 2). — A variety of tviber-bearing Solanum from 

 South Australia is dcscribecl and illustrated as /S. cammersonii. The cultural 

 characteristics of the plant are described in detail. A number of experiments 

 are cited, describing the gradual adaptation of the plant and its development 

 into a product of economic value. The species is deemed especially note- 

 worthy for its resistance to cold and disease. 



Sudan grass, T. B. Hutcheson, E. R. Hodgson, and T. K. Wolfe {Yirginia 

 Sta. Bui. 212 (1916), pp. 3-15, figs. 4). — This bulletin is a general discussion 

 of Sudan grass (Andropogon sorghum), its adaptation to Virginia conditions, 

 and its value as a forage crop. Date and rate-of-seeding tests, tests of seed- 

 ing with cowpeas or soy beans, and seed production experiments conducted at 

 Blacksburg are reported in tabular form and briefly discussed. Analyses of 

 the cured hay of Sudan grass are quoted from Oklahoma (E. S. R., 32, p. 739) 

 and Texas (E. S. R., 33, p. 41). 



For hay, seedings of from 30 to 40 lbs. per acre, broadcasted, are recom- 

 mended as early as all danger of frost is over in the spring and not later 

 than July 1. For seed production, seedings of 20 lbs. per acre, sown in drills 

 from 24 to 30 in. apart, are suggested. Sudan grass may be seeded with 

 cowpeas or soy beans at the rate of 12 lbs. of grass seed to 1 bu. of peas or 

 beans. It is important that the seed be free from Johnson grass, the seed of 

 which it closely resembles. 



A summaiy of the manurial experiments with sugar cane in the West 

 Indies, W. R. Dunlop (West Indian Bui., 15 (1915), No. 3, pp. 212-23^) .—This 

 article reports 25 years of experimental work with fertilizers on sugar cane 

 in the West Indies. These experiments have been conducted in the Leeward 

 Islands (Antigua and St. Kitts), Barbados, Trinidad, and British Guiana, 

 and the results obtained and conclusions drawn at each place discussed in 

 detaU, 



Plats of from 1/20 to 1/30 of an acre are recommended for sugar cane ex- 

 periments. Notes are given on the precision of the West Indian methods, 

 showing the number of plats necessary in fertilizer experiments with sugar 

 cane for a desired percentage difference between average yields when the 

 probable error of one experiment is 12, 15, or 20 per cent. 



Sugar cane on the experimental fields. — Crops of 1914, J. B. Habkison, 

 C. K. Bancboft, and R. Waed (Jour. Bd. Agr. Brit. Guiana, 9 (1916), No. 2, 

 pp. 63-93). — A report of the sugar cane experiments in British Guiana for 1914. 



Considerable space is devoted to a discussion of variety tests, including 

 seedlings and hybrids. Several fertilizer experiments are reported. Nitro- 

 genous fertilizers, especially ammonium sulphate, greatly increased the yield 

 of cane, while phosphorous had very little, if any, effect on cane production. 

 Several soil samples were analyzed mechanically and chemically in an effort 

 to determine any changes that were taking place in the soil. 



Sweet clover, T. S. Pabsons (Wyoming Sta. Bui. 110 (1916), pp. 3-15, fl,gg. 

 4). — The adaptation of sweet clover to Wyoming conditions is discussed and its 

 use recommended. Melilotus alba and Medicago officinalis have both been 

 tested. 



Cultural experiments indicate that sweet clover is especially valuable in 

 Wyoming to prepare heavy, hard, and poor soils for alfalfa, that it will grow 

 on land too wet or too dry for alfalfa, and that it is more resistant to alkali 

 conditions than the latter. The plant is also adapted to growth under irriga- 

 tion or under dry-farming conditions, and produces seed freely in either case. 



Experiments are in progress to determine (1) the value of sweet clover as a 

 fertilizer for the succeeding crops, and (2) its value in a complete crop rota- 



