Hybrid Corn Seed
Breeders produce hybrid
corn seed by cross-pollinating inbred lines. Inbred lines are produced by
self-pollinating (pollinating silks with pollen from the plant's own tassel)
selected plants with desirable characteristics. Since field corn is naturally
cross-pollinated (silks are pollinated by pollen from other plants' tassels),
special processes are used to ensure self-pollination of inbreds. Tassels
and ears are covered with a bag before silk emergence to collect pollen
and to prevent accidental cross-pollination, respectively. Pollen collected
in the tassel bag is dusted over the silk, and the tassel bag is fastened
over the ear to ensure self-pollination.
Development and Production
Commercial hybrid production involves planting male and female inbred
lines in separate rows in an isolated field where possibility of foreign
pollen contamination is rare. The female inbred is normally mechanically
detasselled before pollen shed to ensure cross-pollination by the male
inbred. Male inbred rows are destroyed following pollination to prevent
seed mixture during harvest. Ears from the cross-pollinated female inbred
are harvested, processed, and sold to the producer to plant as hybrid
may be used to produce hybrid seed. Single-cross hybrids result
from crossing two unrelated inbreds (A x B). Crossing the progeny of a
single cross with an unrelated inbred results in a three-way cross
hybrid [(A x B) x C]. Crossing the progeny of two unrelated single crosses
results in a double-cross hybrid [(A x B) x (C x D)]. The vast
majority of commercial hybrids are single-cross hybrids. Single-cross
hybrids generally have higher grain yield and less variability in appearance
and maturity than do the three-way and double crosses because they are
For a graphic representation
of the types of hybrids, contact your county Extension office and ask
for a copy of Information Sheet 1549, Hybrid Corn Seed Development
By Dr. Erick
J. Larson, Extension Agronomist
State University does not discriminate on the basis of race, color,
religion, national origin, sex, age, disability, or veteran status.
Extension Service of Mississippi State University, cooperating with U.S.
Department of Agriculture. Published in furtherance of Acts of Congress,
May 8 and June 30, 1914. RONALD A. BROWN, Director
Copyright by Mississippi State University. All rights reserved.
This document may be copied and distributed for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.