FIELD CROPS. 135 



fcages of lm'ow ing Bugar-beel seed al home are pointed oat. Methods fen- the production 

 of high-grade commercial seed are outlined, the different Bteps in scientific growing 

 of sugar-beet seed are summarized, :m<l the work of this Department in this line is 

 briefly reviewed. 



Field experiments with sug-ar cane, ( '. F. Eckart (Hawaiian Sugar Planters? 

 sin., Div. Agr. and Chem. Bui. IS, pp. /,', plans S). This bulletin considers briefly a 

 few of the more important points in connection \\ itli practical tests with sugar cane 

 in the field, and indicates some of the sources of error which may occasionally arise. 



In considering the modifying influences which may tend to impair tin- results 

 obtained during short periods a simple plal irrigation experiment is taken as an exam- 

 ple, and the nature of plats, preparation of land for planting and the seed cane used, 

 and the treatment of plats with special reference to irrigation are described. The 



actual difference in weights of cane and sugar per acre which may arise from appar- 

 ently trifling variations in the growth of the individual cane plants is pointed out, the 

 figures used ' >« -i i ilt based on an increase in diameter of the cane by , .',, ., , ,',„, and .'. 

 of an inch. Diagrams are presented to illustrate the manner in which small experi- 

 ment fields, either w ith or without irrigation, could be laid out to best advantage. 



The improvement of tobacco by breeding and selection, A. 1>. Shamel 

 i U. S. Dept. Agr. Yearbook 1904, pp. 485-452, pis. 7, fig. 1). — This article points out 

 the need for the improvement of tobacco and its adaptation to soil and climatic con- 

 ditions, discusses the value of large and heavy seed, including the description of a 

 method for the separation of the light from the heavy ^-v<\, and gives general direc- 

 tions for improvement by selection. Record outlines for noting the characteristics 

 of individual seed plants and tin- development of the progeny are given. 



The results of experiments in selection, showing the influence of plant individ- 

 uality, are reported. Ten separate and distinct types were observed in a Meld of 

 Sumatra tobacco and seed was selected from the typical plants in each type. In the 

 young plants produced from this seed the characteristics of each type were quite 

 apparent and became more prominent as maturity approached. It was further 

 observed that the progeny produced about the same number of leaves as the parent 

 plants, in which the number had ranged from 4 to 40. An increase in the number 

 of leaves was not associated with an increase in the height of the plants, but tin' 

 length of the internodes was reduced as the number of leaves increased. 



Thi' shape of the leaf in the parent plant was reproduced in the progeny, and in 

 this connection the value of wide leaves with rounded tips and bases is pointed out. 

 "It has been conclusively proven that any shape of leaf desired, which is produced 

 in a given locality, may be fixed and transmitted uninterruptedly to the succeeding 

 crops by selection of the parents having the desired shape of leaf and saving the seed 

 of such plants under bag." It was also found that the size of the leaf can be con- 

 trolled by selection. Seed from plants free from suckers produced proportionately 

 few suckers, while seed from freely SUCkering individuals produced plants with large 

 numbers of sucker- 



In 1903 the author selected plants apparently resistant to a root disease attacking 

 Sumatra tobacco. "The progeny from these plants weie resistant to t he disease and 



produced a profitable crop of tobacco while the plants grown from other selected 

 svi->\ were as seriously injured as in the previous year. These results are believed 



to BUggest the possibility Ol breeding types resistant to many ol the common tobacco 

 diseases. 



The improvement of tobacco by crossing varieties is also briefly noted. The 

 progeny of crosses made in 1903 with native and imported variety ol cigar tobacco 

 phowed a great improvement in quality, vigor ol growth and yield over the native 

 types. The shape ot the teat was materially modified especially in hybrids of 

 Havana see.l and Cuban and Havana seed and Sumatra the leaves, very round, 

 with regular and uniformly fine veins from the tip to the base, were ot tiner and 



