Managing Frost Risk

A key investment focus for the GRDC is to help grain growers in frost-prone areas manage their farm businesses to minimise yield losses – caused not only by direct losses due to crop damage, but indirect losses due to attempts to reduce the impact of frost by selecting less profitable crops and delaying sowing.

Sudden and difficult-to-predict frosts can have a significant impact on growers, their families and their communities. This page provides access to up-to-date, practical information that can assist growers, even in high-impact years, to accurately assess crop damage and make informed management decisions.

This page provides practical information for growers and advisers, links to useful resources and information about GRDC frost-related investments and its RD&E direction.


Tips and Tactics

Frost damage to cereals is a significant annual production constraint for the Australian grains industry and can result in considerable yield losses. A comprehensive frost management strategy needs to be part of annual farm planning.

The variability in the incidence and severity of frost means that growers need to adopt a number of strategies as part of their farm management plan. These include pre-season, in-season, and post-frost event management tactics.

There are two types of pre-season management tactics available for growers: 1) at the level of farm management planning and 2) within identified frost zones of a farm.

 

 


Making the most of a failed winter crop

Winter crops that fail due to drought, frost, poor pod set or low grain yield potential can be cut as silage or hay. With correct management, a failed grain crop can be salvaged as quality forage.

Failed crops can be cut for hay or silage to cover some costs of growing the crop and in some instances can be profitable, but markets can be volatile. Crop hay and silage can be of very good quality if managed correctly.

Silage is cut at an earlier growth stage, making it of higher quality than hay, but is less cost-effective to transport long distances.

 


Frost Identification Guide For Canola and Pulses

  • Inspect canola and pulse crops between bud formation and pod-fill, if night air temperature falls below 2°C and there is likely to have been a frost.
  • Check low-lying, light-coloured soil types and known frost-prone areas first. Then check other areas. Walk a machinery width into the paddock as crop on outside edge may have less damage.
  • Frost damage can occur randomly, resulting in high variability within paddocks and even on individual plants.
  • Monitor pod development and seed-fill following a frost event by tagging reference plants and checking these a few days later for signs of senescence (death) or continued development.

 


Frost Identification Guide For Cereals

  • Inspect crops 5–10 days after a frost event, particularly when they are between early ear-emergence and grain-filling, and when temperatures fall below 2°C at your nearest weather station.
  • Examine the crop in the more susceptible low parts of the landscape first and if you find frost damage, proceed to higher ground.
  • Walk through the crop and examine a whole plant every 20–30 paces.
  • Peel back the leaves and look for stem damage and damage to the developing head.
  • If the crop is at Z51 (head emergence) or beyond, open the florets on the head to check that the grain is developing.

 


Frequently Asked Questions

Cold damage occurs when plants are exposed to temperature less than 5°C down to -2°C. If this occurs during pollen development (Z39 - 45) it can cause spikelet damage.

Desiccation Damage occurs when ice forms on the outside of the leaves at temperatures from 0°C to -2°C. Moisture is drawn from the leaves leaving them dry and brittle, subsequently dying at the tips.

Freezing Damage usually occurs at temperatures below -2°C when there is rapid ice nucleation and ice crystals form within the leaf. The ice crystals physically rupture cell walls and membranes within the cells causing physical damage. Damage can be seen once thawed as dark green water soaked areas. Ten days after a frost event, bleached leaves, stems, heads and reproductive tissue might be evident.

 


Podcasts

  • GRDC Podcast
    Podcast

    GRDC Podcast: Identifying Frost Damage

    In this podcast WA Department of Primary Industries & Regional Development research officer, Dr Ben Biddulph, discusses what to look for, when and where, to identify frost damage.

    Date: 22 Aug 2019

    Listen on Soundcloud Listen on Apple podcasts


Key Investment Target (KIT) 1.2

Read about the strategy GRDC has developed aimed at helping growers in frost-prone regions.

GRDC Key Investment Target 1.2 - Minimise the impact of spring radiation frost on grain yield and stability.