On the Selection of Rape Seed. 



BY 



C. Kobayashi, A'oe^-aius/'i . 



The quality of a seed is one of the important factors to be 

 considered for attaining a good and rich harvest, and the quaHty of 

 a seed is determined by precisely observing its size, weight, purity, 

 genuineness, germinative energy, germination percentage, &c. 



Several facts has hitherto been found by many foreign investi- 

 gators on these points but there are still some questions as to the 

 relation between the size and weight of a seed and its specific gravity 

 that needs to be cleared up. For cereals and especially for rice and 

 barley some of our investigators, foremost of whom is Prof. T. Yokoi 

 of the Agricultural College, have found that seeds of high specific 

 gravity are generally heavier and have more germinative and 

 vegetative energy and those of lower specific gravity the reverse. 

 Upon this fact the so-called "salt-water selection" or better 

 " specific gravity selection " method was devised in which the good 

 seeds were separated from the bad by floating and skimming off the 

 latter in a saline solution of a moderate specific gravity. It is, 

 however, allowable to doubt if this method can be applied with 

 equal success to rape seeds, which furnish oil. Our object in the 

 cultivation of the rape lies chiefly in getting seeds which are rich in 

 oil ; and for sowing seeds rich in oil must be selected. Further 

 trials were therefore necessary to determine whether seeds rich in oil 

 can be selected by the same method as was applied to cereals or 

 not. 



The object of my investigation was to find out the relation 

 between the physical and chemical characters of rape seed and its 

 quality, and to devise some practical method for the selection of 

 rape seed. 



The results can be summed up under the following headings: — 

 I. The relation between the absolute weight and the specific 

 gravity of rape seed. 



