138 EXPEEIMENT STATION EECOED. 



Planters' Association at its January, 1914, meeting, discusses tlie unfavorable 

 conditions confronting the sugar planters. 



As remedies that will aid the planters to continue to produce sugar at a 

 profit are discussed the following: Increasing tonnage may lessen the cost of 

 production, and this may be secured by enriching the soil and improving the 

 stand and the methods of tillage. As methods of enriching the soil are sug- 

 gested the use of crop rotation with legumes, and the plowing under and making 

 silage of the tops. It is noted that over a million tons of cane tops are burned 

 annually in Louisiana. 



The production of cattle, hogs, dairy products, truck crops, fruits, grain, and 

 forage crops is discussed as diversifications that may gradually take the 

 place of cane growing to some extent with profit, especially on the small farms. 



Sweet potatoes, D. C. Mooring {OldaJioma Sfa. Circ. 25 (IDl/f), pp. 12, figs. 

 3). — This circular gives directions for the production of sweet potatoes, cover- 

 ing the subjects of soil, soil preparation, propagation, pulling "slips," setting 

 plants, cultivation, harvesting, and storing, with a description of 10 varieties 

 of sweet potatoes, and directions for the construction of a wooden sweet potato 

 house. 



Tobacco breeding, H. Lang [J-ahres'ber. Ver. Angeiv. Bot., 10 (1912), pp. 

 18-30, fig. 1). — Ttis article reviews recent work in tobacco breeding, describes 

 modern methods used in producing commercial tobacco and tobacco seed, and 

 gives a plan for breeding plats. 



Variation in tobacco, H. K. Hayes {Jour. Heredity, 5 (1914), A^o. 1, pp. 40- 

 46, figs. 5). — From experiments conducted at New Haven and Bloomfield, Conn., 

 and Forest Hills, Mass., with a Cuban variety of tobacco the author concludes 

 that " environment is of great importance in any system of tobacco breeding, 

 and quantitative characters and especially quality of cured leaf are in a large 

 measure dependent on this feature. Change of environment, however, does not 

 cause a breaking up of type, and whatever variations occur due to environment 

 appear alike in all plants of a particular type. • 



" Heredity is the second important factor, and poor types will give unfavorable 

 results even under the best environmental conditions. Any system of tobacco 

 breeding must take both heredity and environment into account. The only 

 known means of producing variability as a source of new types is by crossing. 

 The number of new forms which will appear due to a particular cross will de- 

 pend on the number of germinal characters by which the parent plants differ." 



A g'enetic analysis of the changes produced by selection in experiments 

 with tobacco, E. M. East and H. K. Hayes (Atner. Nat., 48 (1914), ^o. 565, 

 pp. 5-48, figs. 9). — This paper records data collected to throw light on the 

 theory that continued selection of the extreme values of certain quantitative 

 characters in successive self-fertilized generations of a number of strains pro- 

 duces no changes in the mean values of the characters. 



From observations of the behavior of the character complex number of 

 leaves of numerous families of hybrid tobacco carried to F?. the authors 

 believe they have demonstrated by even these few data that either plant 

 or animal populations can reach such a state of constancy by inbreeding 

 that no profitable results can afterwards be obtained by the practical breeder, 

 and that a homozygous condition does occur in a definite proiwrtion of F2 off- 

 spring and can be propagated commercially at once if a sufficient number of 

 families are grown to be relatively certain of including the desired combination. 

 " As to the problem of theoretical importance, the question of the true con- 

 stancy of homozygotes generation after generation, we believe it to be fair to 

 conclude that a state so constant is reached that even for the theoretical 

 purposes of experimental genetics it may be assumed as actually constant. 



