Take home messages

• GRDC have increased investment in frost research and in 2014 established the National Frost Initiative, an integrated program which addresses genetic, management and environmental approaches to mitigate the effects of frost;
• National Frost Initiative researchers have assessed the relative susceptibility of wheat and barley varieties to frost at the flowering stage; and

Background

Frost has been estimated to cost Australian growers around $360 million in direct and indirect yield losses every year. The GRDC has long acknowledged the severe impacts of frost on crop production, and since 1999 has invested around $13.5 million in more than 60 frost-related projects.

By 2014, GRDC increased investment in frost research to establish the National Frost Initiative (NFI). This five-year, national initiative is tackling frost from several angles and aims to deliver growers a combination of genetic and management solutions to be combined with tools and information to better predict frost events.

The three-pronged initiative addresses:

1. genetics – aiming to rank current wheat and barley varieties for frost susceptibility and identify more frost-tolerant wheat and barley germplasm;
2. management – investigating if there are management practices or preventive products that growers could implement to reduce the impact of frost; and
3. 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.

Objective of the NFI

To provide the Australian grains industry with targeted research, development and extension solutions to manage the impact of frost and minimise seasonal profit variability.

Current status of the NFI

Genetics program

The genetics program of the NFI is led by Dr Tim March from the University of Adelaide, it currently comprises the following projects:

1. Australian national frost program - coordination and phenotyping (UA00136), Jason Eglinton.

This project screens wheat and barley varieties in frost prone areas to identify frost susceptibility and provide rankings of current varieties for growers and advisers. A consistent method is used to screen cereal lines at three sites: Wickepin, WA; Loxton, SA; and Narrabri, NSW. The initial focus was on effects of frost at flowering, but assessments now recognise the potential impact of frost at earlier developmental stages and during grain fill. This will determine if varieties differ in their window of sensitivity to frost which could provide an alternative approach to breeding varieties with improved frost tolerance.

2. Maintaining yield stability of wheat under spring frosts (CSP00180), Ben Trevaskis.

This project is identifying optimal flowering behaviour for wheat and barley crops in frost prone environments. It will identify genes that stabilise yield in frost prone environments through intrinsic frost resistance or by compensating for yield lost to frost. It will also develop molecular markers that can be used by breeders to select for stable yield in frost prone areas.

3. Identification of new frost resistant wheat germplasm from international collections (YOU00002), Ken Street.

This project will identify wheat germplasm with improved reproductive frost susceptibility from international germplasm banks using a Focused Identification of Germplasm Strategy (FIGS) process.

4. New strategies for phenotyping reproductive stage frost and chilling susceptibility in wheat (CSP00143), Rudy Dolferus.

This project is developing a pre-screening method to classify germplasm into chilling tolerant and sensitive groups on their ability to maintain pollen fertility and grain number. The material is also being assessed under frost conditions in the field. The physiological basis of chilling tolerance in cereals is also being investigated.

Management program

Dr Ben Biddulph, Department of Agriculture and Food WA, leads the management program, which comprises the following projects:

1. Farming systems to improve crop susceptibility to frost (DAW00241), Ben Biddulph.

Growers do not have accurate information regarding which farming practices can be cost effectively applied to reduce the financial impact of frost events in wheat crops in different production regions and under varying levels of frost severity. There is anecdotal evidence to support numerous farming practices and products that have the potential to reduce frost damage to crops, including nutrition, stubble burning, grazing and sowing direction.

Products or practices which change the relative susceptibility of the crop or change the flowering window to manage risk in the cropping program will be evaluated at pilot experimental sites in the western and southern cropping regions and co-located with existing ANFP trials. Practices that change the severity and duration of the frost need large scale plots/trials that change in canopy temperature and will be assessed in precision agricultural scale yield trials located in the medium and low production environment in the western and southern wheat cropping regions in conjunction with Living Farm, Facey Group, Consult AG and WANTFA, Western, NSW DPI, University of Adelaide and Birchip Cropping Group.

2. Determining yield under frost- one degree at a time (DAW00234), Ben Biddulph.

This project will add value to the ANFP trials (UA00136) to determine the relationship between the level of frost induced sterility and yield loss in wheat in the southern, western and northern regions. Additionally, the work will identify those cultivars that have a greater ability to compensate from frost damage. Trials are located at Wickepin, WA, Loxton, SA, and Narrabri, NSW. Wheat lines are assessed for response to frost at the three sites using a standardised methodology.

3. Use of chemicals to increase frost tolerance in Australian crops (UWA169), Roberto Busi.

The main focus of this study is to investigate the possibility of inducing frost tolerance in wheat and canola plants through the application of chemical compounds that can temporarily stimulate plant metabolism and confer protection against abiotic stressors. Plants will be grown under controlled, glasshouse, and outdoor field conditions and treated with a range of chemicals including herbicide safeners and insecticides prior to exposure to frost. The most effective compounds capable of minimising frost damage will be identified.

4. Farming systems to improve crop tolerance to frost – crop nutrient management (UMU0045), Richard Bell.

This project explores the area of plant nutrition and its potential role in protecting crops against frost damage. A mixture of nutrients will be applied to crops at levels designed to elevate concentrations of each in the reproductive plant parts during early pollen development and grain filling. Various crop and plant measurements are taken such as canopy temperature, anti-oxidant activity, pollen viability, grain set and grain yield response to determine if improved supply of the nutrients potassium, boron, calcium, copper, magnesium, molybdenum and zinc increase the resistance of crops, particularly wheat, to frost.

Environment program

A leader of the environment program is yet to be appointed, and additional projects will be contracted for the 2015 financial year. It currently consists of the following:

1. Frost situation analysis (UQ00071), Jack Christopher.

This project is quantifying the severity, timing and frequency of frost events in different agro-ecological zones of Australia. Data collected from around 3000 weather stations across Australia is being used to analyse the frequency of frost events in each cropping region. By quantifying the economic impact of frost, the potential impact of research into improved frost management and genetic frost resistance can be estimated.

2. Assessing forecast and management options for mitigating extreme temperature impacts on grains (CMA00002), James Risbey.

Extreme temperature events such as frost and heat stress are not regular occurrences at a given farm, but when they do occur, they can have a major impact on crop yield and profit for a given year. Temperature extremes occur over only a window of a day or days and are not necessarily related to seasonal mean conditions. For this reason, forecasts of seasonal mean conditions are not necessarily helpful in assessing the likelihood of changes in extreme events within a season. Preliminary work suggests that this is especially the case for late frost events. In other words, climate science can say more about the average minimum temperature than the number of frosts, and more about the number of frosts than the likelihood of a late spring frost.  The relationship between seasonal means and extreme likelihoods will be assessed in this project. 

New output for 2015

Frost susceptibility data for most commercial wheat is now available after three years of research across Australia as part of the GRDCs NFI.

Seventy-two wheat lines were assessed through the Australian National Frost Program (ANFP – UA00136). The work has involved the development of a nationally consistent and coordinated method of assessing field based frost damage in cereals which previously has not been available to the Australian industry. The frost susceptibility data is generated from research trials based at Loxton, SA, Merredin and Wickepin, WA, and Narrabri, NSW over the last three seasons.

The results are available on the NVT website, www.nvtonline.com.au, and are based on each variety’s relative susceptibility to spring radiation or reproductive frost, which occurs in late winter to early spring.

The GRDCs investment in the ANFP is an example of a significant pre-breeding project which is developing industry capacity and methodologies that will enable not only the independent screening of newly developed cultivars from commercial breeding companies, but also introduced germplasm to identify increased levels of frost tolerance for Australian growers.

Contact details

Francis Ogbonnaya, GRDC
4 National Circuit, Barton, ACT 2600
02 6166 4500
Francis.Ogbonnaya@grdc.com.au