1!>-'0J FIELD CROPS. 139 



have indicated that the viKor of the sprout under equal conditions deteruiiiies 

 the vi^or of tlie phint. In the varieties studied it was found tliat the nunilxu- 

 and distriI)ution of tlie tirst f^eneration sprouts produced under favorable grow- 

 ing,' conditions are a good indication of tlie relative seed value of the tul)ers. 



From a study of the changes occurring in RIcCorniick potatoes, after the 

 vines have been killed by frost, it is pointed out that under these conditions 

 the growth processes in the underground parts of the plant continue for some 

 time. This tends to form small tubers at the expense of the large tubers, and 

 therefore makes it advisable to harvest the potatoes as soon as possible after 

 a killing frost. It is stated that sometimes, under the conditions described, 

 small tubers are formed on the sui'face of the larger ones. 



Prairie rice culture in the United Statos, C. E. Chambliss ([/. S. Drpt. 

 Agr., Formers' Bui 1092 {1920), pp. 26, figs. 13).— The extent and importance 

 of the industry is briefly considered, the general requirements of prairie rice 

 culture are discussed, and directions for the various cultural operations in- 

 volved are given. The sources of irrigation water and the method of applying 

 it are described, and tlie more important varieties adapted to the conditions of 

 the prairie i"ice regions are noted. 



Soy bean experiments, F. W. Stemplei {West Virginia Sta. Bui. 112 {1919), 

 pp. 3-19, Jiga. 3). — The progress of soy bean culture in West Virginia is re- 

 viewed, descriptive data of varieties tested at the station are tabulated, and 

 the results of various cultural experiments are reported. 



In general, Wilson was the best seed-producing variety tested at the station, 

 tlie average yield for five years being 17.01 bu. per acre. Peking, a small seeded 

 varlety,^^ave an average of 16.19 bu. per acre for the same period. A compari- 

 •son of soy beans and co\viieas as hay crops showed an average yield of 2.4S 

 tons of soy-bean hay and of 1.7 tons of co\\i:»ea hay per acre. The varieties 

 reconmiended as high seed and hay producers are Wilson, Peking, Virginia, 

 Arlington, Roosevelt, and Jet. 



An experiment in growing soy beans for hay in combination with other 

 crops resulted in better yields and in more readily curing of the hay than when 

 the soy beans were grown alone. Soy beans grown with either Sudan grass or 

 millet proved very satisfactory. Soy beans and corn in 1915 produced 10.16 

 tons of silage per acre as compared witli 8.97 tons where corn alone was grown. 

 •V rotation experiment with corn, soy beans, or Sudan grass and rye gave data 

 Indicating that combinations of tliese crops giving three yields in two years 

 are possible. 



In seeding tests, soy beans sown in rows 30 in. apart at the rate of 3 pk. 

 per acre produced an average of 3.5 tons of hay per acre on five plats, while 

 '.similarly solid drilling at the rate of 6 pk. per acre gave a yield of 3.45 tons. 

 j Seedings made June 1 at G different rates, ranging from 3 to 8 pk. per acre, 

 I pave in all instances higher yields than were obtained from similar seedings 

 : made June 10 and July 3. 



[ The results of harvesting the crop at different stages of maturity indicated 

 I that the highest yields of green or uncured material, dry matter, and protein 



ii" obtained when the crop is harvested with the pods fairly well tilled out 



' '1 the leaves just beginning to turn in color. The yields and the composition 

 lie hay when the crop was harve.sted at different stages of growth are given 

 a tables. Lime applied shortly before sowing soy beans had a comparatively 

 1 Imlted effect on the yield. 



Further studies in fertilizing and storing sweet potatoes, II. P. STrcKEY 



'"■oriiia Std. Bui. 13.'f {1919), pp. 7'.J-(S7). — Earlier work on these subjects has 

 a previously noted (E. S. II., 31, p. 436). The experiments here reported, in 

 185972°— 20 4 



