1907.] PLANT BREEDING — PRINCIPLES AND RESULTS. I23 



advantage in planting corn which came from the eighty bushel 

 row. 



I have found in a comparison of a number of ears that the 

 smallest ear sometimes yields the greatest amount of grain in 

 the next generation, when planted by the row system. The 

 explanation is that this ear came from a strain that possessed 

 to a remarkable degree the power of transmitting good yield- 

 ing qualities, and while this individual happened to be small, 

 possibly through disadvantage in environment, it still had the 

 hereditary qualities of the strain from which it came. 



The breeding plot is given only ordinary farm treatment 

 through the season, and the only extra work is that of detassel- 

 ing all even numbered rows so that we may have opportunity 

 to select our seed from corn that is known to be the product 

 of a cross, and thus avoid the dangers which come from in- 

 breeding. It is also recommended that no plants in any of 

 the rows which appear imperfect, dwarfed, immature, barren, 

 or otherwise undesirable, should be allowed to mature pollen. 

 Occasionally an entire row should be detasseled because of the 

 general inferiority of the row as a whole. Detasseling is ac- 

 complished by going over the rows as many times as may be 

 necessary and carefully pulling out the tassels as they appear. 

 Indeed, great care should be exercised in this part of the work 

 in order not to injure the plants and thereby lower the yields. 

 The tassels should not be cut off, as this produces an external 

 injury and at the same time the stalk is often deprived of 

 several undeveloped leaves. The tassel should be allowed to 

 develop far enough so that it can be separated alone at the top 

 joint by a careful pull. This insures cross pollination and 

 markedly increases the yield of succeeding crops. 



Making Selections. 



In the fall, selections of the best ears borne on the best 

 stalks are made from the detasseled rows, as was done from 

 the general field in the previous year. These ears are har- 

 vested when mature, and placed together with all those from 

 the same row, in bags marked with the row numbers. Then 

 each of the forty-eight detasseled rows is harvested and each 

 row weighed up separately, together with the selected corn 

 from the same row. 



