Рет қаралды 91,877
Hybrid maize seed provides farmers with
varieties with improved genetic characteristics,
such as high yield potential and combinations
of unique characters to combat diseases and
adverse growing conditions. However, the quality
of the hybrid seed depends fundamentally on the
production methods in the field that are used --
which must comply with standards that guarantee the
quality-- and the implementation of an agronomic management
appropriate. Although the seed production of varieties
of open-pollinated maize is relatively simple, the
hybrid seed production requires the application of
additional field practices that are essential to
achieve good production.
The production of hybrid maize seed requires that
deliberately cross a parent population
female with a male parent, in isolated plots. Thus, the
identity and the location in the field of the two populations
Parents determine the outcome of production
since the beginning. Each hybrid variety consists of a
specific combination of a female parent (which
produces the seed) and a male parent (which produces the
pollen). Field management of these parents is also
very important and requires being vigilant to sow in
the right moment, eliminate atypical plants, remove the
spikes to females before they produce pollen, harvest
separate the female seed, and shell and process with
take care of the seed in order to maintain its quality. The success of
This process depends on the sequence in which it is carried out, since
any mistake made in the early stages of the
itself will have a significant effect on the following, and a
error or a serious problem can lead to total failure or
crop rejection. This manual provides a guide to
the production of hybrid maize seed, and makes particular
reference to the procedures in the field, so that the
producers and seed companies can obtain,
cost-effective, productive seed and
quality for farmers.
What is a corn hybrid?
In simple terms, a corn hybrid results when
one corn plant fertilizes another that genetically does not
is related to the first. The plant that produces
the seed is called the female or seed parent,
while the plant that provides the pollen for
fertilize the female is called a male parent or
pollen. In other words, a female plant is crossed with
a male plant in order to produce hybrid seed. Is
seed possesses a unique genetic makeup, the result
of both parents, and produces a plant with certain
features. Plant breeders generate the parents
female and male of each hybrid in order to create offspring
with certain characteristics, such as a specific maturity,
disease resistance, certain grain color, quality
processing etc This is the unique hybrid seed that
farmers will plant in their fields. When a
farmer buys the seed of a certain hybrid, he hopes that
he has a performance in the field equal to that indicated in the
variety description.
In the case of corn, there are several types of hybrids, such as
the single hybrid, triple hybrid, double hybrid and hybrid
half Blood. Each type has a different parental configuration,
but in all cases, the hybrid seed that is sold to
farmers is a cross between two parents: a
female and a male. Like the male and female organs
of the corn are separated, it is relatively easy to make
a cross between two plants. In a production field
of hybrid seed, the male and female parents are
planted following a design of consecutive furrows, and
normally the number of plants or female furrows is
three to six times greater than the number of plants or rows
masculine. The male flower (the spike) of the female plant
is removed (detasseled) prior to pollen production,
in order for the pollen to reach the female flower (the ear)
of the female plants comes only from the spikes
of the male plants. It is necessary to unpin
females so that their pollen does not pollinate the stigmas
feminine. When this happens (a process known
as "female self-fertilization"), the result is a
significant loss of the quality of the seed that is generated,
and that is clearly seen in the cultivation that is produced
sow that seed. Therefore, female self-fertilization
should be avoided by all means.
The ratio of female rows to male rows in the field
it is normally 3:1, in the case of simple crosses
and triples, but it can be 8:1, in the case of
double hybrids The proportion that actually
is sown depends on several factors, mainly on
the pollen production of the male, the height of the ear of the