Fast-tracked trials push sowing date boundaries
Date: 24 Apr 2015
How early is too early to start sowing grain crops?
This has been a question on the minds of many Western Australian grain growers with wet soil in paddocks following significant rainfall over recent months.
In some areas, growers have received more than 200mm since January and a few have capitalised on this moisture by sowing crops from the beginning of April.
In response to this year’s seasonal conditions, the Grains Research and Development Corporation (GRDC) is funding new trials to test the validity of sowing crops very early to take advantage of higher than average rainfall at the start of the year.
The trials – located north-east of Yuna and Pindar in the north-eastern grainbelt, and near Hyden in the south-eastern grainbelt - have been initiated and fast-tracked through the GRDC’s Regional Cropping Solutions Networks (RCSN) initiative.
According to Geraldton-based Department of Agriculture and Food (DAFWA) researcher Christine Zaicou-Kunesch, there is virtually no existing field trial data around times of sowing earlier than April 25 – the traditional start to crop planting in WA.
She says the long-term, optimal sowing date for grain crops is known to be about May 10, but this might not apply in some exceptional seasons.
In WA’s Northern Agricultural Region, the 2006 season started similarly to this season, with substantial rain falling over summer in low rainfall zones.
But this early rain was followed by a long dry spell until a late ‘break to the season’ on June 23.
The topsoil remained largely dry and did not link up with the wet subsoil, causing a severe drought.
Ms Zaicou-Kunesch says that in hindsight, many growers believed sowing an area of wheat (and possibly canola) from early April, instead of waiting until June, could have resulted in better yields.
This year, small plot trials at Yuna and Pindar are focusing on a range of wheat and canola varieties with different season lengths, sown at two seeding rates (normal and low) at three times of sowing – April 9, April 25 and May 10.
The wheat varieties include Yitpi, Trojan, Mace and the longer-maturing winter wheats Forrest and Wedgetail.
A canola trial focusing on triazole tolerant (TT) varieties is co-located with the wheat trials.
Objectives will include comparing yields from the different sowing dates and determining which varieties perform best at early sowing times.
The work will also validate the ability of the decision tool Yield Prophet® to make accurate predictions based on very early sowing dates, and determine if seeding rates have a substantial impact on the outcome of sowing wheat early.
Craig Brown of Synergy Consulting is conducting the GRDC RCSN early sowing trials near Hyden.
The work involves small plot wheat, barley, canola and oat trials sown at different times, including very early in April.
These trials, focusing on a range of varieties, will test the validity of sowing crops early to take advantage of higher than average summer and autumn rainfall in this region.
The aim of the work is to develop a strategy for very early sowing as a percentage of all crops sown, in order to spread risk.
Variety yields and development will be used to validate whether Yield Prophet® can reasonably simulate outcomes from very early sowing.
Some farmers in the region where the Hyden trials are being conducted have been experimenting with very early sowing – from late March onwards – for more than 15 years.
Anecdotal evidence is that it has been a valuable tool as a percentage of crop plantings.
Roger States, GRDC grower services manager
0427 565 780
Christine Zaicou-Kunesch, DAFWA
08 9956 8549, 0408 459 603
Natalie Lee, Cox Inall Communications
08 9864 2034, 0427 189 827