Agriculture Reference
In-Depth Information
3
Breeding Objectives
between all these factors are likely to have an effect on
the breeding strategy. It is only after answering these
questions that breeders will be able to ask:
INTRODUCTION
The first exercise which must precede any of the
breeding operations (and indeed a task that should be
continually updated) is preparing a breeding plan or
setting
breeding objectives
. Every breeding programme
must have well defined objectives that are both econom-
ically and biologically feasible. Many new cultivars fail
when they reach the agricultural practice. In some cases
these failures are associated with the wrong economic
objectives. Similarly many excellent new genotypes fail
to become successful cultivars because of some unfore-
seen defect which was not considered important or was
overlooked in the breeding scheme.
Objectives then are the first of the plant breeder's
decisions. The breeder will have to decide on such
considerations as:
What type of cultivar should be developed?
•
How many parents to include in the crossing scheme,
which parents to include, how many crosses to exam-
ine, to examine two-way or three-way parent cross
combinations and why?
•
•
How should progeny progress through the breeding
scheme (pedigree system, bulk system, etc.)?
•
What characters are to be selected for or against in the
breeding scheme and at what stage should selection
for these characters take place?
•
How to release the variety and promote its use in
agriculture?
PEOPLE, POLITICAL AND
ECONOMIC CRITERIA
What political and economic factors are likely to be
of greatest importance in future years?
•
•
What criteria will be used to determine the yielding
ability required of a new cultivar?
The final users of almost all agricultural and horticul-
tural crops are consumers who are increasingly removed
from agricultural production systems. In 1863, the
United States Department of Agriculture (USDA) was
created and at that time 58% of the US population
were actual farmers. Indeed only a few decades ago, the
majority of people in the western world were directly
involved in agricultural and food production. However,
in 2006, less than 2% of the United States popu-
lation were directly involved with agriculture. This
past century therefore has resulted in a dramatic shift
away from working on the land to living and work-
ing in cities. Agricultural output has, and continues, to
increase almost annually despite fewer and fewer peo-
ple working directly in agriculture than ever before.
•
What end-use quality characters are likely to be of
greatest importance when the new releases are at a
commercial stage?
•
What diseases or pests are likely to be of greatest
importance in future years?
•
What type of agricultural system will the cultivar be
developed for?
All these will need to be considered and extrapolated
for a time that is likely to be 12 to 14 years from the
onset of the breeding scheme. It should also be noted
that politics, economics, yield, quality and plant resis-
tance are not independent factors and that interactions
