How to minimise frost damage this winter

FROST DAMAGE: Dr Peter Hayman said severe frost damage was a low frequency but high consequence event.
FROST DAMAGE: Dr Peter Hayman said severe frost damage was a low frequency but high consequence event. Cassandra Glover

SEVERE frost damage was experienced throughout the region in 2017.

Peter Hayman spoke about risks of frost damage, and ways to manage it, at the Allora GRDC Update recently. Frost is estimated to cost the grains industry $300 million every year.

Dr Hayman said frost damaged the reproductive part of the plant.

"We grow these crops to get the grain,” he said.

"Chickpeas or canola or other grain crops, we want to get the seeds from this.

"When we get frost that damages the flowering parts, or the early stages of pod setting, and grain fill and so on in these different crops, the freezing damages that.

"There might be a lot of biomass and leaf matter there, but not grain.”

Dr Hayman said there was no way to avoid frost completely.

"There's information on trying to make sure that flowering time is after that frost period. Tools like CliMate and so on that can help with doing that,” he said.

"But because we are also dealing with heat and water stress, and last year is a good example, even though we had all these frosts in August, in September there was incredible heat. So it's this balancing act between heat, water stress, and frost.

"Getting that balancing right is very difficult. One way to do it is partly diversity. Knowing where on the farm are the most frost-prone areas.

"And knowing something about the long-term risk timing of frost and getting the planning right for that.”

Dr Hayman said the severe frost damage experience in 2017 was a low frequency but high consequence event.

"It is likely that there are more frequent but less damaging losses in most years,” he said. According to GRDC and WA DIPIRD, cold damage can occur when when wheat plants are exposed to temperatures less than five degrees which can cause spikelet damage if it occurs during pollen development.

"From zero degrees to two degrees moisture is drawn from the leaves, resulting in desiccation damage,” Dr Hayman said.

"The greatest damage is freezing damage which usually occurs at temperatures below minus two degrees.

"The damage is caused by ice crystals physically rupturing cell walls and membranes.”

The GRDC National Frost Initiative conducts research and development to manage the impact of frost and maximise grower profit. The initiative has three components - genetics, management and environment.

The genetics initiative aims to develop more frost-tolerant wheat and barley germplasm as well as ranking current varieties by frost susceptibility.

The management initiative aims to develop best practice crop canopy, stubble, nutrition and agronomic strategies to minimise the effects of frost, and search for new products that may minimise the effects of frost. The environment strategy aims to predict the occurrence, the severity and the impact of frost events on crop yields.

Dr Hayman said it was important to acknowledge the psychological effects frost damage could have on farmers.

"Some farm businesses are very hard hit in some years. It's uneven in that regard.

"Psychologically it's tough because people have already spent the money on the crop, and it's towards the end of the season when they're starting to think about harvesting.

"If there's a really bad drought, you know its bad from the beginning whereas a late frost is understandably difficult.”

Topics:  allora canola chickpeas dr peter hayman frost damage grains grains research and development corporation grdc

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