Dec. 10,1917 Breeding Sweet Corn Resistant to the Corn Earworm 551 
a selected strain of the variety in which Mr. 0 .F. Cook had first observed 
the worm resistance; Marrainto is a variety from northern Mexico, with 
rather thicker and harsher husks than those of Brownsville. These also 
extend well beyond the ear. 
Isolated plantings of the first generation of these crosses were made at 
Victoria in 1913. The four lines which have been continued are PI175 
Brownsville X Early Cory; PI177 Early Evergreen X Brownsville; PI179, 
Stowell X Brownsville; and Ph8o, Marrainto X Evergreen. The ears from 
the first-generation hybrid plants contained a mixture of sweet and 
horny seeds. The sweet seeds from selected ears of each of the four 
hybrids were planted in separate rows at Lanham, Md., in 1914, one 
row from each ear. 
The procedure in 1914 was to make pollinations between plants of a 
similar appearance, and usually within the same row. The distance the 
husks extended beyond the ear, the thickness and number of husks, and 
the extent to which husk leaves were developed were recorded for all 
plants used in making pollinations. An attempt was also made to grade 
the plant with respect to the texture of the husks. 1 In selecting plants 
for pollination preference was given to those with long husks and few husk 
leaves; but other types were also pollinated, including a few that were 
distinctly inferior with respect to the characters thought to denote 
worm resistance. 
Fourteen ears were selected for ear-to-row tests in 1915. The desig¬ 
nations of these ears with their ancestry are given in Table I. 
Table I .—History of the corn plantings made at Chula Vista, Cal., in igi$ 
1912. Victoria, Tex. 
Original cross. 
1913, Victoria, Tex. 
Treatment. 
1914. Lanham, 
Md. (Sweet 
seeds planted.) 
Plant combi¬ 
nations. 
1915. Chula 
Vista, Cal. 
Planting desig¬ 
nation. 
Brownsville X Early Cory 
Bo. 
Bo. 
Bo. 
Evergreen X Brownsville. 
Bo. 
Bo. 
Stowells X Brownsville. .. 
Bo. 
Bo. 
Bo. 
Bo. 
Marrainto X Evergreen. .. 
Evergreen X Brownsville. 
Stowells X Brownsville 
Isolated block... 
.do. 
.do. 
.do. 
Hand-pollinated 
.do. 
.do. 
Isolated block... 
.do. 
.do. 
.do. 
.do. 
Hand-pollinated 
.do. 
Isolated block. 
121X122 
124X122 
1X9 
8Xm 
10X12 
12X10 
12X15 
159X158 
137X75 
140X138 
89X30 
162X160 
182X179 
32 
X 
21 
Phi2t 
PI1123 
PI1127 
Phi 28 
Phi 29 
Phi3° 
Phi3i 
Phi 20 
Phl22 
Phi24 
PI1125 
Phi26 
Phi 18 
Phi 19 
1 The surface of the husks in the hybrid progenies is distinctly harsher than in commercial varieties of 
sweet com. It was not found possible, however, to distinguish the different progenies in this particular 
with serviceable accuracy and the notation of the character has been discontinued. 
