Expi;riments in bre;e;ding sweet corn. 273 



to the acre, while ear No. i produced a row yielding but 25.77 

 bushels to the acre. Ear No. i had but 76.22 per cent, of its 

 total yield on ears good enough for seed, while ear No. 113 has 

 93.42 per cent, of its total yield on such ears. 



Again ear No. 113 may be compared with No. 116. The 

 latter was certainly the better looking ear, yet it yielded at the 

 rate of 10 bushels to the acre less than No. 113. 



Ear No. 127 (Fig. 224), which was a smaller ear (66.50 

 grams shelled corn) than any ear in Fig. 225 with the exception 

 of ear No. 60, yielded at the rate of 41.38 bushels to the acre 

 as against 29.38 bushels to the acre, the highest yield of any of 

 the ears shown in Fig. 225, that of ear No. 132. 



Ear No. 127 (Fig. 224) produced a row yielding at the rate 

 of 1.38 bushels per acre higher than the row produced by ear 

 No. 138 (Fig. 224), which was relatively a giant beside it. 



Ear No. 139 (Fig. 224) produced one of the highest yielding 

 rows in the test, giving 45.50 bushels to the acre, yet this ear 

 had the smallest net weight of shelled corn (61.90 grams) of 

 any of the 5 ears shown in Fig. 224. Ear No. 29 (Fig. 225) 

 was one of the heaviest ears selected (bearing 88.10 gr. shelled 

 corn) yet it produced a row yielding at the rate of but 26.62 

 bushels to the acre. 



These facts are very striking. They indicate that there is 

 not that close association between the size and type of the ear 

 and the resulting yield, which many would have us believe. The 

 proper method of studying this matter is, of course, to measure 

 matlicmatically the correlation between ear characters and yield. 

 This is being done in this laboratory, but a technical discussion 

 of the results is not in order here. These photographs show 

 clearly enough that such an association of characters and yield 

 cannot be very close or definite. This is a result in accordance 

 with some data recently published by Williams and Welton of 

 the Ohio Station.* 



The point may be raised that in Figs. 224 and 225 we are deal- 

 ing with extremes in the positive and negative directions. What 

 would be the type and size of ears producing good average yield- 

 ing rows? Such rows would in our 1908 experiment be repre- 

 sented by yields of from 33 to 36 or 37 bushels. In figures 226 

 and 227 data are given for an examination of this question. 



* Williams, C. G., and Welton, F. A. Ohio Agric. Exp. Sta. Bulletin 

 212, 1909. 



