INFLUENCE OF SIZE OR WEIGHT OF SEED KERNEL. 33 



The average difference in yield at the end of three years between large grains (607 per 

 ounce), commercial sample (689 per ounce), and small grains (882 per ounce), with Med- 

 iterranean wheat, was 2.06 bushels in favor of large grains as compared with the commercial 

 sample, and 5.18 bushels in favor of large grains over small grains. The difference in yield 

 Ix'tutTM the large grains and the commercial sample chiefly occurred the first year; but it 

 i- |><t-.-.il>!e. though hardly probable, that the difference was partly due to variation in the 

 soil. The experiment has been carried on in different parts of the field for the last two 

 years, and the difference in yield is now only 0.32 bushel per acre in favor of the large grains. 



Cobb" reports tests of various grades of wheat kernels with respect 

 to size, and concludes that large kernels give better yields of grain. 

 The seed of one year was not the product of the corresponding grade 

 of the previous one. 



GrenfelP selected plump and shriveled kernels from the same bulk 

 of grain. Of these 150 kernels were sown in each row, with rows of 

 plump and shriveled kernels alternating. The germination in both 

 rows appeared much alike, but the plants in the rows sown froin 

 plump grain soon began to gain on the others and kept ahead for the 

 remainder of the season. The tillering was better in the plump- 

 grain plants. Grenfell tabulates his results thus: 



As bearing upon this subject some experiments conducted by 

 Riinker r are of interest. He weighed each of the kernels of a large 

 number of heads of wheat of the Spalding Prolific and Martin Amber 

 varieties, and found that the. heaviest kernels occur in the lower half 

 of the spike. With spikes of different lengths and weights, the 

 weight of the average kernel increases with the size of the spike. 



Weights of individual kernels from the same spikes show that 

 there is a great range in this respect. One spike, of which R tinker 

 gives the weights of all the kernels, and which is given as representa- 

 tive of the average, shows kernels varying in weight from 36 to 71 

 milligrams. 



Agricultural Gazette of New South Wales, 14 (1903), No. 2, pp. 145-169. 

 & Agricultural Gazette of New South Wales, 12 (1901 ), No. 9, pp. 1053-1062. 

 <* Jour. f. Landw., 38 (1890), p. 309. 



27889 No. 7805 3 



