34 



Relation 

 between com- 

 pactness of 

 head and 

 strength of 

 straw. 



Relation 

 between 

 number of 

 kernels in the 

 spikelet, and 

 yield and 

 quality. 



as a distinct species (Avena orientalis Schreb.), forms a fifth. In comparing 

 these types with the industrial values of the sorts it seemed to be shown 

 that the group in which the panicle assumed a more rigid upright position 

 was as a rule the most productive. Such a conclusion, however, has had to be 

 modified since investigation of the tables of yields of the different sorts over 

 many years shows that among the stiff panicled sorts are to be found many 

 which are among the lowest average yielders of all those tested. As instances, 

 may be mentioned the sorts having the stock-book numbers 0310, 0326, 0404 

 and 0452. There cannot therefore be accepted as an infallible guide, any 

 definite type of panicle. 



In wheat and oats the character of the head was believed to be asso- 

 ciated with strength of straw, investigations seeming to show that a dense, 

 compact head and a stiff, strong straw go together. Here again numerous 

 exceptions have caused this idea to be modified. 



Highly interesting investigations into the relationship between the 

 number of kernels in the spikelets of oats and wheat and the yield and quality 

 of the crop were made by Nilsson during the years when these crops were 

 under his direct charge. The number of kernels in a single spikelet of oats 

 is usually from one to two, although three is not uncommon. In wheat 

 as many as six may be found, although from three to four is generally 

 the case. For purposes of investigation Nilsson defined three classes of 

 spikelets: three-kernelled (S 3 ), two-kernelled (S 2 ) and one-kernelled (SJ. 

 These are illustrated below. 



FIG. VII. Different Classes of Spikelets. (Author del.) 



It would seem natural to conclude that in spikelets such as S t which 

 contain but one kernel (a) that this would be larger than kernel (a) in 83. 

 which contains three kernels. The following, however, was found to be the 

 rule : 



1. "That the development and weight of each kernel stand in a 

 striking and significant relation with the number of kernels in the spikelet; 

 but 



2. "That with a rising number of kernels there is associated a con- 

 siderable increase in weight per kernel instead of the opposite which one: 

 would expect. 



