



















SPINDLY 
ig. STALK 
HOW IS HYBRID 

CORN PRODUCED ? 
STEP 1 A selected stalk of some pre- 
viously open pollinated variety (or of a 
hybrid cross) is self pollinated by fertilizing 
its silks with pollen from its own tassel. 
STEP 2 Kernels from this  self- 
fertilized ear grow into a variety of 
kinds of corn—the inbreeding brings 
out the ‘‘hidden meannesses.’’ Only 
the most desirable plants are per- 
petuated by continued inbreeding— 
undesirable plants are discarded. 

. > a i aS. 
ae SCEPTIBLE FLINTY LATE DESIRABLE 
LODGING smut Barrenness SUTTOID EAR MATURITY «= PLANT 
STEP 3 After three to ten or more years of 
this inbreeding and selecting process, a 
‘‘nurified inbred’’ is obtained. This is a 
desirable plant, but the continued inbreed- 
ing has dwarfed it and it produces only a 
small nubbin-like ear. It can be multiplied 
indefinitely by continued inbreeding. 
-STEP 4 Experimental crosses 
are made, each involving 2 to 4 
different ‘‘purified inbreds.”’ 
Crosses of two or more unrelated 
inbreds exhibit ‘‘hybrid vigor’’ 
and are normal in size. These 
experimental crosses are tested. 
STEP 5 The desirable crosses, 
the ‘‘happy marriages’’ are pro- 
duced in commercial quantity for 
seed by planting the foundation 
strains in isolated fields, leaving 
the tassels on the ‘‘male’’ strain 
and keeping them pulled out of 
the ‘‘female.’’ Seed is saved only 
from the detasseled stalks. 

