1918] FIELD CROPS. 537 



higher temperatures. Further investigations are to be made to determine the 

 optimum temperature conditions. 



The sugar beet seed industry in France, L. Malpeaux {Vie Agr. et Rurale, 

 7 {1917), No. 19, pp. 332-3S7). — Tlie commercial production of sugar beet seed 

 is discussed, and selection based on chemical and genealogical analyses, and se- 

 lection on the farm outlined. 



It is estimated that the cost of production would approximate $77.73 per 

 acre, and that with a yield of 1,780 lbs. per acre the cost of production of the 

 seed would be approximately 4.36 cts. per pound. 



Sugar cane experiments, 1914—16, J. de Verteuil {Bui. Dept. Agr. Trinidad 

 and Tobago, 16 {1917), No. 1, pp. l-llf). — Extensive cane variety tests are re- 

 ported for four experimental centers, with tabulated data on acre yields and 

 the percentage and general composition of the juice. 



Experiments are reported in which the top, the center, aad the bottom por- 

 tions of the cane were compared to ascertain their relative value for sugar 

 production. Ripe canes of B. 156 were employed and were cut and topped in 

 the usual manner. The upper 10 or 12 in., containing 3 or 4 joints, was cut off, 

 and the remaining portion cut into two equal lengths. The percentage of juice 

 extracted amounted to 54.6 for the tops, 65.2 for the centers, and 67.4 for the 

 bottoms, with sucrose contents of 7.52, 17.93, and 17.76 per cent, respectively. 



[Report of sugar cane work in Hawaii], H. P. Agee, G. F. Renton, J. T. 

 MoiK, and J. Hind {Haivaii. Sugar Planters' Sta., Proc, 36 {1916), pp. 13-124, 

 pi. 1, figs. 4). — The following reports, dealing with field tests with sugar cane, 

 were read and discussed before the thirty-sixth annual meeting of the Ha- 

 waiian Sugar Planters' Association: Report of the Director of the Experiment 

 Station, Report of the Committee on Cultivation, Fertilization, and Irrigation 

 on Irrigated Plantations, Report of the Committee on Culivation and Fertiliza- 

 tion on Unirrigated Plantations, and the Report of the Committee on Cutting, 

 Loading, and General Transportation. 



Cuban varieties of sweet potatoes, J. T. Roig and G. M. Fortun {Estac. 

 Expt. Agron. Cuba Bol. 33 {1916), pp. 76, pis. 32, fig. i ) .—Forty-seven types of 

 sweet potatoes found in Cuba are listed, classified as white, yellow, violet, and 

 red, and briefly described. The cultural practices involved in sweet potato 

 growing are described and the uses of the crop and its importance in Cuban 

 agriculture discussed. Insects and diseases attacking the crop are noted. 



The comparative efficiency of indexes of density, and a new coefficient for 

 measuring square-headedness in wheat, S. Boshnakian {Jour. Amer. Soc. 

 Agron., 9 {1917), No. 5, pp. 231-247, pi. 1, figs. 5).— The comparative efficiency 

 of the indexes of density now in use are analyzed and a new coefficient pre- 

 sented as a substitute for the present methods of measuring compactness, which 

 do not show the differences between the three types of compact wheats, namely, 

 the squarehead, Triticum capitatum, the club, T. compactum, and squarehead- 

 club, T. coiiipacto-capitafum. An instrument for determining the density or 

 squarehead coefficient of large numbers of heads, and which simultaneously 

 divides the rachis into three equal parts, registers the length of the rachis, 

 and registers the third of the length of the rachis, is described and illustrated 

 as designed by the author and constructed by the Office of Cereal Investiga- 

 tions of the U. S. Department of Agriculture. 



Four of the older formulas are compared, including those of Derlitzki and 

 Neergaard, with reference to their application in measuring different types of 

 wheat heads and to determine the experimental errors involved in their opera- 

 tion. The author concludes that of the formulas given " the average internode 



55096°— 18 4 



