Grains Research and Development

Date: 29.06.2016

Pre-seeding planning to manage frost risk in WA

A wheat crop sown with a mix of Wyalkatchem wheat and Yitpi wheat to reduce exposure to a frost event.

A wheat crop sown with a mix of Wyalkatchem wheat and Yitpi wheat to reduce exposure to a frost event.

Frost is a complex and erratic constraint to Western Australian cropping systems which can result in dramatic consequences to a grower’s business.

CSIRO climate applications scientist Dr Steven Crimp investigated frost trends dating back to the 1960s across southern Australia. His research findings show that since the 1960s:

  • WA’s frost window has widened and on average frosts start three weeks earlier and finish two weeks later in the year.
  • Consecutive frost events have increased by an average of up to three days at a time and mostly occur in August and September in the frost prone regions.
  • The frosts are getting colder minimum temperatures.

 Due to the nature of frost and its damaging effects, an integrated approach to managing it is recommended. This means complex decisions are required that involve strategically combining information on environmental, management and genetic approaches to cater to your personal situation.

Risk assessment, property mapping, crop type, variety choice, sowing time and stubble load are key pre-seeding decisions that growers can use to reduce the risk of crop losses from spring frosts in high risk areas.


Grains Research Updates

Can we refine planting dates further

GRDC Project Code: AMPS00010

Author(s): Matt Gardner (AMPS Research), Jules Dixon (Formally AMPS Research), Greg Giblett (Agromax Consulting), Sam Simons (Agromax Consulting) and Stephen Towells (AMPS Research)

Date: 28.02.2017

• Of all the agronomic “levers” available to growers planting date still offers one of the greatest abilities to increase yield potential.
• There are drastic changes in frost risk with only small changes in elevation (20-50 m), which presents significant opportunity to push planting dates forward without necessarily increasing frost risk.
• Lower points in the landscape/paddock have more frost events with greater duration compared to higher elevations. Therefore there is slower accumulation of growing degree days at these lower points in the landscape, consequently slowing the development of the crop.
• There is little variation in maximum temperature across elevations. Therefore in lower parts of the landscape, where the frost risk persists longer into the season, the heat stress will start at the same time as higher elevations. This narrows the window for optimum conditions for flowering crops.

Grains Research Updates

An analysis of frost impact plus guidelines to reduce frost risk and assess frost damage

GRDC Project Code: UQ00071

Author(s): Jack Christopher (1), Bangyou Zheng (2), Scott Chapman (2), Andrew Borrell (1), Troy Frederiks (3) and Karine Chenu (1)

Date: 20.07.2016

• Growers need to consider carefully whether earlier sowing is justified in seasons where warmer temperatures are predicted.
• Warmer temperatures may reduce the frequency of frost events but also increase the rate of crop development bringing crops to the susceptible, post heading stages earlier.
• Situation analysis of national frost impact indicates substantial losses in all regions averaging approximately 10% using current best practice.
• In the northern region, there are even greater losses in yield potential due to late sowing.
• These results indicate that continued research into reducing frost risk remains a high priority despite increasing temperatures.
• Variety guides and decision support software are useful for matching cultivars to sowing opportunities.
• Current variety ratings based on floret damage may not provide a useful guide to head and stem frost damage.
• Crops become most susceptible to frost once awns emerge.
• If crop temperature at canopy height drops below -3.5C after awn emergence, crops should be assessed for damage.
• Consider multiple sowing dates and or crops of different phenology to spread risk.

Portrait of Tim March and Ben Biddulph Media Releases

Grains industry welcomes frost susceptibility rankings

Date: 12.04.2016

Grain growers in Victoria, South Australia and Tasmania will this year, for the first time, be able to factor frost susceptibility of wheat and barley varieties into their cropping programs. more

Magazine cover image

Managing frost risk - Northern Southern and Western Regions

Date: 09.02.2016

Managing frost risk - Northern, Southern and Western Regions more