A step closer to high yielding wheat with low lodging risk
Author: Toni Somes | Date: 07 Oct 2016
A wet spring could make lodging an issue in wheat crops across the eastern Australia this season, but new research may soon reduce the risk for growers in high rainfall and irrigated areas.Wheat with dramatically reduced lodging potential could soon be a reality with germplasm from the Grains Research and Development Corporation (GRDC) funded Better Irrigated Wheat Germplasm (BIWG) project likely to be delivered to seed breeding companies within two years.
The project aims to pave the way for better adapted wheat varieties improving crop production and profitability for growers in both irrigated and high rainfall areas.
Lodging is a significant issue in New South Wales and Queensland and makes it challenging to reliably achieve yields of more than seven tonnes per hectare. In 2008 alone, regional losses from lodging were estimated to have totalled at least $20 million due to lower yields and increased harvesting costs.
CSIRO crop physiologist and Better Irrigated Wheat Germplasm project leader Dr Fernanda Dreccer said early trials had produced some “exhilarating” results. Her progress is backed up by a team effort involving expertise in crop physiology, genetics, plant breeding and agronomy supported by biometrics expertise by the GRDC-funded project Statistics for the Australian Grains Industry (SAGI).
“Through this research we aim to identify lodging resistant lines and transfer the lodging resistance into regionally-adapted elite germplasm,” she said.
“Ultimately the project wants to deliver traits and regionally-adapted germplasm, which has stable high harvestable yields of above 7t/ha with reduced lodging potential, to Australian plant breeding companies so they can produce commercial varieties for growers.
“This season the first crosses from the project have been planted at Gatton and this will provide invaluable data for researchers and breeders.”
New GRDC Northern Panel chair John Minogue is a vocal supporter of the BIWG Project describing it as critical research for Australian wheat growers with significant implications across high rainfall and irrigated regions.
“Importantly this project has trial sites from Emerald in Central Queensland to Spring Ridge in New South Wales, which gives the research robustness and should give growers’ confidence in the results,” Mr Minogue said.
“The project’s goal is to provide the foundations for improved, regionally-adapted wheat varieties with high yield potential and the ability to perform consistently under irrigation or high rainfall areas to maximise returns to growers.
“As a grower myself, and in my new role as northern panel chair, I feel strongly that GRDC research must be firmly focused on projects like this, which have at their core the goal of improving grower productivity and profitability.”
Dr Dreccer, a Queensland-based CSIRO researcher, said traditionally Australian wheat breeding efforts have focussed on improving crop yields under water-limited conditions, rather than for high yielding environments.
So she said just as the agronomy needed to be different for irrigated environments, so did plant genetics.
“In dryland environments average yield is around 1.5t/ha whereas we started out with expectations of 7t/ha for irrigated wheat yields.”
Dr Dreccer said the project involved evaluating varieties, elite breeding material from breeding companies, and other promising germplasm with lodging resistance traits in trials at Gatton, Narrabri, Spring Ridge and Emerald.
Lodging resistance is a complex area and involves characteristics associated with stem failure and/or failure of the root system to support the plant, which plant breeders cannot afford to test for.
According to Dr Dreccer, stem and root lodging were important crop management considerations in the northern region due to the potential for heavy rain events that was often accompanied by strong winds.
“We have been focused on two traits to reduce lodging potential. The first is the plants’ anchorage capacity through development of a large crown root, essential to keep plants upright in wet heavy clay soils. The second is stem strength.
“It is a tough program because at the same time we want to develop wheat that produces greater yields. In effect this means we are trying to develop wheat that has additional weight in the head, or yield ability, and at the same time has resistance to falling or superb anchorage ability and stem strength.
“So we are not searching for a single trait, but rather a combination of traits that allow us to meet the goals of growers.”She said little was known about the frequency of lodging risk in the northern region or genetic variation for lodging risk at different levels of high yield. The information her project is generating could help come up with those figures.
“Additionally there are unknowns about the genetic control of lodging, and the best selection method for efficient and large-scale screening for reduced lodging, two aspects that the project is starting to investigate having identified appropriate germplasm and tools.”
She said aside from stem and root lodging issues her team was also investigating how the structure of crop canopies could play a role in reducing lodging potential.
“To some extent we need a plant stem that has strength as well as some flexibility to move in harmony with the wind and this depends on several factors, including stem height and stiffness and ear weight. It is technically known as natural frequency, and captures the canopy’s ability to move with the wind.”
She said her team were committed to contributing to wheat varieties, which were more suited to conditions and continued to produce higher yields with less issues for growers.
“As well as the germplasm work our team also contributes to what is happening in grower paddocks now, by evaluating advanced breeding lines from breeding companies and benchmarking them against current cultivars in irrigated trials in four locations across the northern region,” Dr Dreccer said.
“I feel what we are doing is very valuable, with the potential to have a positive impact on income for both the Australian industry and globally, as irrigated and high rainfall areas are key contributors to global wheat production.”
Fernanda Dreccer, CSIRO Crop Scientist
07 5466 3010, 0408 885 137
GRDC Project Code CSA00041