Australia
May, 2005
|
Title |
Optimum sowing time of
new wheat varieties in Western Australia
|
|
Description |
Agribusiness Crop Updates
- Western Region - February 2005 |
|
GRDC Projects* |
DAW00012 |
|
Authors |
Darshan Sharma, Brenda
Shackley, Mohammad Amjad, Christine M. Zaicou-Kunesch
and Wal Anderson , Department of Agriculture WA;
Northam, Katanning, Esperance, Geraldton and Albany
|
|
Paper reviewed by: |
Jeff Russell, Wal Anderson |
|
Presented |
Perth, WA |
Key Messages
The response of wheat varieties
to sowing date as tested over the last two years showed a wide
range of optimum periods depending on the location and seasonal
conditions. Given that the range of varieties available does not
have large differences in maturity, the groups of varieties had
overlapping periods when they reached their maximum grain yield.
Calingiri achieved its best
yield if sown as early as mid-May while the optimum sowing time
for Annuello
 ,
Drysdale
,
EGA Jitarning
,
Rees
and Odiel was late-May to early-June.
Cultivars like Spear, Carnamah
,
EGA Eagle Rock
,
WAWHT2499, Westonia, Wyalkatchem
and Yitpi
had relatively wider sowing windows and performed best from
sowings during mid-May to mid-June.
Aims
To highlight the performance of
new wheat varieties at different times of sowing in Western
Australia and determine the variety-specific sowing period when
a given variety will achieve its maximum in a given environment.
Method
Eighteen Cultivar x Time of
sowing trials involving 33 local and interstate released
varieties and 8 crossbreds were conducted across the State
during 2003 and 2004. The trial locations were: Mullewa,
Mingenew and Eradu in the North; Mukinbudin, Quairading and
Avondale in the Centre; Nyabing, Jerramungup and Katanning in
the South; Salmon Gums, Gibson and Scaddan in the South Coast
area. Trial sites represented predominant soil type and crop
rotation combinations in the regions. Each trial was a
replicated, row-column design with as much balance as possible.
Plot size was around 28 m 2 and trials were sown and
harvested using small plot machinery.
The first sowings were made on
the first available opportunity after the break, with 2-3 week
intervals for subsequent sowing dates. Plots were seeded at
approximately 100 plants/m 2 and were given adequate
nutrition as per local practice. Trials were kept disease and
pest free following standard practices.
Grain yield data on each trial
was analysed using Genstat. Grain yields were calculated for
each variety relative to the yield at the highest yielding
sowing time (called 100). Relative grain yields were plotted
against sowing date (for example, see Figure 1). For each region
considering all trials over the two years, the period when the
variety reached it's maximum yield was considered to be it's
optimum sowing period.
Results
The optimum sowing times of new
varieties and crossbreds for each region are given in Table 1.
Since no sowing opportunity was available before mid-May,
conclusions about the earlier limit of the sowing window should
be taken with caution.
Cultivars Annuello
,
Calingiri, Chara
,
Datatine, Drysdale
,
EGA Jitarning
,
Odiel and Rees
and the crossbreds RAC1055, EGA 2248 could be sown up to early
June in most parts but Calingiri is the variety with the
earliest start of optimum period (mid-May).
The optimum sowing periods for
other mainstream varieties (grown over > 1% of the sown area in
2004), Carnamah
,
Westonia and Wyalkatchem
,
were relatively wider (mid-May to mid-June) which coincides with
the most common seasonal break time throughout the State. The
new cultivars EGA Eagle Rock
(recommended for whole of the State), crossbred WAWHT2499 (to be
released February 2005), WAWHT2524 (scheduled to be released in
August 2005) and the old, widely adapted variety Spear also fall
in this group.
Cultivars Bowerbird
,
GBA Ruby
,
GBA Shenton
and EGA Bonnie Rock
had optimum sowing times between late-May to mid-June in most
parts of the State.
Figure 1. Relative grain yield
of wheat cultivar Wyalkatchem at different sowing times in the
Great Southern region in 2003 and 2004. The optimum sowing
period in this set was estimated as early to mid-June.
Conclusion
There are two important
questions regarding varietal choices in relation to the time of
seasonal break and the seeding schedule: (i) What are the most
profitable varieties in a given region at a given sowing time?
and (ii) What is the optimum period when a given variety will
achieve its best?
The answer to the first
question lies in the grain yield (t/ha), grain quality (grain
protein) and delivery standards (for example, screenings, black
point, falling numbers) at a given seeding time of a given
variety in comparison to other available varieties. The results
on this aspect have been compiled and presented in separate
papers for each region in this book.
The answer to the second
question lies in Table 1. Matching the variety to the sowing
time is the key to maximising farm yield and varietal
performance.
Acknowledgments
The authors are thankful to
growers for trial sites throughout the State; Mario D'Antuono
for statistical analysis; Veronica Reck, Melaine Kupsch, Anne
Smith and Judy Devenish for technical support; Research Support
Units of the Department of Agriculture for trial operations; and
to GRDC for funds.
Table 1. Optimum sowing time of
different varieties in the four wheat growing regions of Western
Australia
MM = mid-May (10-20 May); LM =
late May (21-31 May); EJ = Early-June (1-10 June); MJ = mid-June
(11-20 June); LJ = late-June (21-30 June); Values within
brackets show the number of data points on which the conclusion
is based. Less confidence can be placed on estimates made on
less than 10 observations.
Varieties displaying this symbol beside them are protected under
the Plant Breeders Rights Act 1994.
Source:
http://www.grdc.com.au/growers/res_upd/west/05/sharma.htm
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information in this publication. |
