832 EXPKKIMEXT STATION ItHCJOED. L Vol. 41 



(ibsei'vatioiLS vi\ lol);icco soils, rotations, and fei'tilizers (pp. Kl— 10) and on co- 

 operative lertilizer tests (pp. 41-44) by H. A. Freeniau. 



Mechanical auals'ses are presented of 44 soils and subsoils now producing 

 flue-cured tobacco in Canada, and the conclusion reached that the best soil 

 for this type of tobacco is a loose, porous sand from 6 to 10 in. deep, underlaid 

 by a sand to sandy loam subsoil with good natui'al drainage. Chemical 

 analyses of a few of these soils are included and Indicate a rather low state of 

 fertility. Tests with commercial fertilizers are said to have given good re- 

 sults. The use of a complete fertilizer containing sulphate of potash, acid 

 phosphate, and sulphate of ammonia or dried blood is recommended. The 

 maintenance of fertility and the best conditions for growth are believed to be 

 dependent upon a proper system of crop rotation. Turning under a clover 

 crop just preceding ])]anting to tobacco resulted in an inferior yield of poor 

 quality. Observations on the proportion of stalk to leaf secured in Canada 

 showed an average of 55.2 to 44.8. It is thought that a larger proportion of 

 leaf could be secured, together with an improvement in quality, through earlier 

 and lower topping. 



The 1919 yields from ten wheat fields in " Egypt," C. G. Hopkins et al. 

 {Illinois Sta. Circ. 236 {1919), folio). — This circular reports the wheat harvest 

 from 10 different experimental fields on which crop rotation systems and 

 fertilizer experiments are being conducted. 



[The cultivation of the greater yam (Dioscorea alata)], I. H. Bitkkill 

 (Gardens' Bui. Straits Settlements, 2 {1919), .Yo. 4, pp. 129-135).— Thin com- 

 prises a progress report on cultural tests with D. alata conducted at the Singa- 

 pore botanic gardens during 1918. See also a previous note (E. S. R., 40, p. 

 637). 



The longevity of Bacillus radicicola on legume seeds, C. K. Felleks {Soil 

 Set., 7 (1919), No. 8, pp. 217-232). — Bacteriological and vegetation experiments 

 conducted at the Nev/ Jersey Experiment Stations are described in which an 

 effort was made to ascertain the viability of B. radicicola on soy bean and 

 alfalfa .seed subjected to varying conditions of inoculation and held in storage 

 for different lengths of time. 



Evidence is presented to show that such seed inoculatetl with nodule in- 

 fusion retained viable nodule-forming organisms on the seed coat for from 

 six to nine months, while plants grown from these seeds possessed nodules on 

 their roots. The soy bean and alfalfa organisms appeared to withstand about 

 the same degree of desiccation. The shortest period of time (five minutes) 

 that the seeds were kept in contact with the inoculant gave nearly as good 

 results as longer periods. The use of gum tragacanth did not aid materially 

 in prolonging the vitality of the bacteria, and the use of this material or 

 similar substances is deemed inadvisable. Infected dry soil dusted upon moist 

 seeds gave better results than sterile dry soil dusted upon moist inoculated 

 seeds. Soil inoculation did not prove to be any more effective than inoculation 

 with nodule infusion or commercial cultures. Commercial cultures gave as 

 good results as nodule infusion. 



In general the niimber of bacteria per seed and the number of nodules per 

 plant were not closely correlated, it being apparent that only a few of the 

 cells present on a seed were capable of nodule production. It is stated that 

 this ratio may be as 1 : 1,000,000. It is also deemed probable that those or- 

 ganisms which resist desiccation longest possess the greatest infeetibility. 

 The greatest destruction of cells occurred within the first few hours after in- 

 oculation, after which they perished relatively more slowly and uniformly. 



