74 Richard H. Boerker 



conclusive. Only in the case of the corn was there a sufficient 

 difference to warrant a conclusion in favor of the heavy seed. 

 From the results of these experiments it seems logical to conclude 

 that in general more vigorous growth and consequently a better 

 stand in the field is secured by employing only the heavier seed. 

 The effect of the size and weight of seed on production has been 

 with no other plant so extensively studied as in the case of the 

 wheat. The majority of results seem to favor the view that large 

 and heavy seed are preferable. Zavitz (28) showed that the 

 yield in bushels per acre was in favor of the large plump seed. 



Trabut (32) found in the case of tobacco seeds that it was 

 possible to affect a separation into heavy and light sorts through 

 the capacity of these two kinds respectively to sink and float in 

 water. It was found that the heavy seed produced plants which 

 were greener, more vigorous, and of larger size. The yield from 

 plants from the heavy seed was almost double that of the yield 

 from the light seed. Shamel (31) secured results similar to 

 these. Careful comparative tests of the light and heavy seeds of 

 tobacco have proved that the best developed and most vigorous 

 plants are always produced from the large, heavy seed while the 

 light seed produce small, irregular and undesirable plants. In 

 an experiment with Cuban tobacco seed Shamel found the 

 germination of heavy seeds almost perfect while less than five 

 per cent, of the light seeds sprouted. The plants from the heavy 

 seed grew more rapidly than those from the light seed and 

 reached the proper size for transplanting seven to nine days 

 earlier than the plants from the light seed. 



In the case of cotton seed, comparative production tests of the 

 value of the heavy seed over the usual farm product have been 

 made by the U. S. Department of Agriculture (30). The yields 

 in pounds on equal areas in South Carolina show the gain from 

 the use of heavy seed in two different cases to be 10.9 per cent, 

 and 8.25 per cent, respectively. 



Bolley (29) selected large and small grains from the same 

 heads of wheat and found that the large grains generally pro- 

 duced the largest yields. Waldron (29) found that short wheat 

 culms, shortheads, and those with a smaller number of grains 



