Winter
Wheat Improvement has Global Impact
For many years, CIMMYT and ICARDA have jointly
conducted winter wheat research. Initially, CIMMYT worked with partners
in temperate countries to cross winter and spring wheats. The goal was
to improve CIMMYT's spring wheats and their partners' winter wheats. Over
time, however, the scope of CIMMYT's research widened to include improving
winter wheats in developing countries. In 1971, CIMMYT began working directly
with Turkey's winter wheat improvement program through an association
with the Rockefeller Foundation/Government of Turkey wheat research
program. ICARDA also had a winter and facultative wheat program since
its inception in 1977. However, it was only in 1990 that Turkey's Ministry
of Agriculture, CIMMYT, and ICARDA joined forces to conduct research on
winter wheats through the International Winter Wheat Improvement Program
(IWWIP).
In support of IWWIP, Turkey generously provides access to its research
institutes and other infrastructure, enabling Turkish, CIMMYT, and ICARDA
scientists to distribute new winter wheat varieties to more than 120 breeding
programs in 50 countries. This is the largest international network for
breeding winter wheat. Though much of the research is done in Turkey,
complementary research--for example, molecular fingerprinting or breeding
for insect resistance--is done elsewhere by CIMMYT and ICARDA.
Winter wheat breeders have only one growing season per year to do their
work. It takes 12-15 years to breed a new variety and get it into farmers'
fields. To date, 27 varieties developed by IWWIP have been released, and
35 others are scheduled for release. Given that IWWIP started just 17
years ago, this number is impressive. Progress has been good partly because
researchers crossed winter wheats with spring wheats developed by CIMMYT
in Mexico. More than 75% of the IWWIP wheats that have been released or
are scheduled for release are crosses between winter and spring wheats.
Another impact of IWWIP has been its steady collaboration with Afghanistan.
Despite the two decades of war and many years of drought, Afghanistan's
researchers have continued their work on wheat improvement. Through the
Swedish Committee for Afghanistan and FAO, Afghan researchers maintained
contact with IWWIP and selected the best new wheat varieties from international
nurseries. Although Afghanistan's infrastructure was destroyed, new wheat
seed still moved from farmer to farmer. Without this seed, the Afghans
would have suffered even more hunger and malnutrition over the years.
All winter and facultative wheat cultivars currently registered in Afghanistan
are derived from these nurseries.
Spring, Winter,
and Facultative Wheat: What's the Difference?
A wheat variety's growth habit limits its survival
to certain geographical areas. Knowing the distinctions between
winter, spring, facultative, fall-sown, and spring-sown wheat
can make the difference between crop failure and a bumper crop.
People often use the time of sowing to define whether a variety
is a spring or winter type. In most of the CWANA region, wheat
is sown in fall or winter.
Winter and facultative wheats need exposure to cold (5-10°C)
for three to six weeks after they germinate, or they cannot
produce grain. They start to grow before winter sets in, when
they become inactive. Vernalization--a temperature response
mechanism--ensures that winter wheat and other plants adapted
to cold climates do not enter their reproductive growth stages
prior to winter. The plants resume rapid growth in the spring
as temperatures rise.
Spring wheats have a continuous growth cycle with no inactive
period and spring wheats die if exposed to temperatures below
-10°C for more than 12 hours. Facultative wheats tolerate
cold more than spring wheats and less than winter wheats, but
they do not require extended exposure to cold temperatures to
reproduce. These wheats are found in transition zones between
true spring and winter wheat regions.
Confusion over wheat types can have unfortunate consequences.
When seed is imported to help farmers cope after natural disasters
or war, for example, a mistake can be catastrophic. Farmers
who mistakenly sow winter wheats in springtime or in warm areas
will harvest only grass, not grain. CIMMYT and ICARDA can advise
relief organizations about appropriate wheat seed and prevent
disastrous mistakes from occurring.
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Wheat Facts:
CWANA and the Global Context
The leading producers of wheat in the developing
world are China, India and Turkey with production levels of
108, 71 and 20 million metric tones annually, respectively.
Of the roughly 100 million hectares planted to wheat in the
developing world, about 70% is planted to spring wheat and about
30% to winter and facultative wheat.
No other region in the world devotes so large a proportion of
arable land to cereal production as CWANA. For example, as much
as 70% of arable land in Turkey and Iran is planted with wheat.
Just under two-thirds of the entire CWANA wheat crop is rainfed.
All of the top 10 countries with the highest per capita wheat
consumption in the world are located in CWANA. Tunisia and Algeria
top the list, with per capita annual wheat consumption of 208
and 198 kg, respectively. More than 90% of the CWANA wheat crop
is consumed as food, and provides more than half of the calories
in people's daily diets.
Due to the rapidly growing populations in CWANA, most countries
strive to produce as much wheat as they can to meet domestic
demand and limit imports. However, the production is not enough
to meet demand and many countries have to import large quantities
of wheat. In 2002, the leading importers of wheat worldwide
were Brazil, Iran, Algeria, and Egypt with 7, 5.7, 5.3 and 4.9
million metric tons imported, respectively.
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