Underestimating frost damage in crops could be costly
Date: 26 Sep 2014
Grain growers and their advisers are being urged to thoroughly inspect their crops for frost damage to avoid unexpected yield losses later in the season and unnecessary input expenses.
Agronomic experts believe that the extent of damage from recent frost events in South Australia, Victoria and New South Wales could be substantially underestimated.
They say that crops must be inspected with rigour and that it is imperative to check the stems and not just the heads because of the early season timing of frost events.
Identifying the extent of damage is a critical first step in deciding what management options are going to be most suitable given individual circumstances.
The Grains Research and Development Corporation (GRDC) has responded to recent severe frost events by organising emergency frost management workshops across the southern cropping region.
The workshops, initiated by the GRDC Southern Regional Panel, have been attended by hundreds of growers and advisers who have been provided with an insight into why these early frosts have occurred, as well as information on how to identify frost damage and the likely success of various management strategies.
Members of the Southern Panel witnessed first-hand the extent of frost damage during their recent annual spring tour.
Panel member Bill Long, who is also an SA-based agronomist and grain grower, says damage from the August frosts has been widespread but the full impact is yet to be known.
“Damage is more commonly associated with frosts that occur in spring so to have a winter frost have so much impact is unusual,” Mr Long said.
“While the extent of crops hit by frost is evident in some areas, it is likely that damage is being underestimated. It is therefore critical that growers have a really close inspection of their crops, take samples and check them thoroughly to determine if they have been affected.
“If crops have been severely impacted by frost and a decent yield is unlikely, it would be a considerable waste of money applying urea or fungicides over the remainder of the season, so growers need to know what they are dealing with,” he said.
“Making an early call on management of frost-affected crops is important. For example, if they are going to be cut for hay, the sooner that is done the better.
“If the conclusion is that harvesting won’t be economical, there are a number of options, and the best choice depends on a number of factors that the grower needs to assess with their agronomist.”
Agrilink consultant Mick Faulkner has been one of the presenters at the frost management workshops, offering participants practical advice on how to look for frost damage and how to best manage affected crops.
“Frost is harder to deal with than drought – it is a great big smack in the face and it tests our resilience,” Mr Faulkner said.
In determining frost damage in crops, Mr Faulkner and other experts recommend the following actions:
- Take numerous samples of plants from across a paddock. Check the stem for damage (discoloration and rotting) as well as the head. In many instances, heads are emerging sterile.
- Place plant samples in a bucket with water and food colouring. Over a period of time, healthy plants will take-up the coloured water (visible in the heads) while frost-affected plants will remain unchanged.
- New green tillers growing from the base of a plant are another indicator of frost damage.
The GRDC, which continues its long-term commitment to funding frost-related research, recently launched a national frost initiative focused on identifying and delivering practical genetic and management solutions to assist growers to manage the impact of frost.
The $15 million, five-year national initiative will tackle frost from several angles and aims to deliver growers a combination of genetic and management solutions.
The three-pronged initiative will address: genetics – aiming to develop more frost-tolerant varieties; management – investigating if there are preventive products, stubble and nutrition management practices or other measures that growers could implement to reduce the impact of frost; and environmental prediction – focusing on predicting the impact of frost events on crop yields and mapping frost events at the farm scale to enable better risk management.
More information on frost and its impact on crops can be found in the GRDC Managing Frost Risk booklet which is available for viewing and downloading via www.grdc.com.au/GRDC-Booklet-ManagingFrostRisk.
A GRDC Fact Sheet on managing the risk of frost is available via www.grdc.com.au/GRDC-FS-FrostRisk. To assist with identification of frost damage in crops, the GRDC’s Back Pocket Guides are a useful resource and can be found at www.grdc.com.au/GRDC-BPG-FrostCereals and www.grdc.com.au/GRDC-BPG-FrostPulses.
The GRDC has also published online resources in response to recent frost events, see http://www.grdc.com.au/News-FrostDamageConcern-0914 and www.grdc.com.au/FrostedCrop.
Bill Long, GRDC Southern Panel
Phone 0417 803034
Mick Faulkner, Agrilink
Phone 08 8843 4282
Sharon Watt, Porter Novelli
Phone 0409 675100
GRDC Project Code ARO00002, CSP00143, CSP00180, UWA00160, DAW00162, DAW00234, DAW00241, MCV00010, SDI00019, UQ0071, UA00136, UWA00161
Region South, North