THE FINAL “FOUR-WAY” HYBRID CROSS— the fourth step 
I 
W HEN THE SEED SUPPLY used in planting 
the two "single crosses” becomes large 
enough, the final "four-way” hybrid seed is pro¬ 
duced in large Pioneer crossing fields from which 
the commercial seed corn is harvested. 
These fields require hundreds of capable men 
each summer for detasseling work. The fields are 
detasseled from twelve to fifteen times. 
Pioneer corn breeders alternate four rows of one 
"single cross” (AxB) with one row of another 
"single cross” (CxH) all through a field. Each 
group of four rows (female) is detasseled, and the 
pollen from tassels of the one row (male) cross- 
pollinates the silks of the detasseled rows. The 
result is a "four-way” hybrid cross. 
Pioneer Hi-Bred Seed Corn is picked only from 
the detasseled rows. The corn harvested from the 
male rows pollinates itself and cannot be used as 
hybrid seed corn. 
HUNDREDS AND HUNDREDS OF CAPABLE DETASSELERS WORK IN PIONEER SEED FIELDS EVERY SUMMER 
