REPORT - Search CIMMYT repository

Micro-Plot Variety Trials (MPVT) located in
farmers fields.
For two consecutive years, the line/C272
(Willet x Norin 10-Brevor)/Sonora 64 with the
pedigree Pk-146-12a-4a-1 a, has significantly
outyielded Mexipak 65 both in the research
station trials and MPVT. This line has now
been named Chenab 70. It was included this
year (1969-70) in the International Spring Wheat
Yield Nursery assembled by CIMMYT. The
preliminary data received while this report is
being written shows Chenab 70 at the top of
the list in yield in Mexico, Saudi Arabia, Lebanon,
South Yemen and Pakistan. The average
yield of Chenab 70 in 26 semi-commercial
trials in West Pakistan was 25% better than
Mexipak 65. Sufficient seed of Chenab 70 will
be available to sow somewhere between 10,000
to 15,000 acres during the fall of 1971.
Blue Silver (sister line of Sonalika) and
Green Valley (sister line of Chotti Lerma) have
also shown outstanding yield performance in
the MPVT. Khushal and Norteno 67 maintained
their good performance compared to Mexipak,
especially from late dates of sowing.
Triple Dwarfs -
Development
the New Phase of Varietal
The most progressive farmers are now
clamoring for varieties with shorter straw and
greater resistance to lodging than that present
in Mexipak 65. Many progressive farmers are
now fertilizing at a very high level, 120 to 140
pounds of nitrogen per acre, and irrigating
properly. Under these conditions Mexipak 65
sometimes lodges. To overc"me this problem
the Accelerated Wheat Production and Improved
Program has been developing for the
past three years a large number of triple dwarf
lines. These lines when grown with optimum
fertilizer and irrigation reach a height of no
more than 70 cms. Some of these triple dwarf
lines have been selected to homozygosity and
are now available for use in more intensive
agronomic studies. Plans are being made for
conducting a series of agronomic studies during
1970-71 on the most promising lines so as
to determine the optimum seed rates, spacing
and levels of fertility for maximum yields.
Among the most promising triple dwarfs are
a large number of lines (more than 2,500) selected
in Pakistan from the CIMMYT Bluebird
Cross 23584 [(Ciano "S" x Sonora 64-Klein
Rendidor) x Mexipak]. Among a large number
of other triple dwarfs showing outstanding
promise are the following lines:
1. (Yt 54 E -GABO x 5840) MEXIPAK 65
Cross PK 2384-2a-Oa.
2. (Sonora 64-Tzpp x Y54) MEXIPAK 65 x
Y50 E Cross 11-26036-1 a-1 OOa.
3. (1409-3093 x 5840) aT 254 MEXIPAK 65
Cross PK 2366-12a-Oa.
4. (1409-3093 x 5840) at 254 MEXIPAK 65
Cross PK 2366-13a-Oa.
Changing Emphasis
As production of wheat has risen dramatically
over the past three years it now provides
an opportunity to strengthen those aspects of
research which by necessity because of limitations
in staff and bUdgets, were not given top
priority when the effort was being made to
achieve a production breakthrough. Among
these are the plant pathology and cereal chemistry
aspects of wheat improvement.
Improvements in Rust Resistance
Greater protection from rust is being sought
through two different approaches. The first is
to establish a permanent Summer Breeding
Nursery Station in the northern hills. The second
is through extensive inoculation studies
whereby thousands of lines showing promise
in the general breeding program are evaluated
for resistance in both the seedling and adult
plant stage of development.
During the past two years two young Pakistani
scientists who have studied at CIMMYT
have been developing skills in rust research.
Green house facilities are being developed at
the Ayub Agricultural Research Institute to
facilitate this work.
Funds have now been made available for
establishing a permanent summer nursery station
in the northern hills, perhaps in Kaghan
Valley. This will greatly enhance the selection
of varieties with a broader and deeper spectrum
of rust resistance. It will also speed up
the rythm of the entire breeding program,
permitting the growing of a much larger number
of lines in the summer nursery than has
been possible in the past.
Cereal Technology
Cereal technology has largely been neglected
in the wheat program in the past. Two
cereal technology laboratories are now available,
and three young Pakistani scientists have
received practical training in this discipline
while studying at CIMMYT during the past two
years. Plans are being made to activate both
laboratories during the 1970-71 season.
92