Investment in science and industry development key to profitable agrifood sector 2

HIGHLIGHTS

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  Small pointed snails do not actively seek baits.
  
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  Windrow burning can decrease snails.
  
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  Sprays are not efficacious for slug or snail control.
  
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  Baits are still the best option for snail and slug control.
  

Funding and collaborators

GRDC, SARDI, Stirlings to Coast Farmers, Fitzgerald Biosphere Group, RAIN, Southern Dirt, SEPWA, DRD Royalties for Regions.

Research officer Svetlana Micic plots.

Small pointed snails on the underside of a canola plant.

Making herbicide choice and application reliable and safe for growers

Science team: Dr Harmohinder Dhammu and John Moore (project leaders), Mark Seymour, Richard Snowball, Paul Matson, Neville Chittleborough, Gerry Skinner, Kazue Tanaka, Meg Slattery, Kevin Powis, Dr Kith Jayasena, Svet Micic.

Herbicides are the main management tool for weed control in broadacre production systems of WA. Crop varieties are known to differ in their tolerance to herbicides and this can vary between regions or locations.

Small reductions in grain yield due to herbicide damage may be acceptable if weeds are strongly competing with the crop but yield reductions greater than 10% due to herbicide phytotoxicity may be as significant as weeds in limiting crop returns.

DAFWA researcher Dr Harmohinder Dhammu was part of a national herbicide-tolerance screening project (NSW, Qld, SA, WA) until early 2016. The project was designed to provide growers with clear information about herbicide interactions for individual varieties. for WA.

The project tested the tolerance to common in-crop herbicides on varieties of wheat, barley, oats, peas, chickpeas and lupin emerging from the National Variety Testing (NVT) program. This was to ensure that the tolerance to important herbicides is known at the time of a new variety’s release.

The project also tested new chemistries on WA’s common crop varieties in collaboration with chemical companies, and developed guidelines for the safe timing of old products like the phenoxy herbicides on new wheat varieties.

All crop varieties tested were tolerant to more than 70% of the registered herbicides at the label rates and timings. The remaining herbicides caused yield losses of 10–25% but in some cases up to 50%.

Drift of pesticides is of increasing community concern and strategies to mitigate drift without compromising efficacy or yield are being developed.

HIGHLIGHTS

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  A permit application based upon joint DAFWA and GRDC research is before the APVMA (Australian Pesticides and Veterinary Medicines Authority), which will allow oat growers to use trifluralin to manage ryegrass in oat crops for higher profitability.
  
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  A series of genotype x environment x herbicide identical trials were simultaneously conducted across five states. These highlighted the degree of variation in herbicide response across environments and genotypes and showed agro-ecological region specific testing over longer periods would be advantageous.
  
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  Results from all the herbicide tolerance trials can be accessed via NVT Online (www.nvtonline.com.au).
  
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  Distribution of pesticides within the canopy using UV dyes and image analysis has allowed better recommendations for nozzles, adjuvants and setups to minimise drift while maintaining efficacy.
  
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  SnapCard, a mobile phone app that growers can use to measure spray performance, was developed and tested in these projects.
  

Funding and collaborators

GRDC, RIRDC, UWA, SARDI, UQ (CPAS)

DAFWA Research Officer Dr Harmohinder Dhammu assessing field trials at Katanning

Weed watch: alert for new and emerging threats

Science team: Dr Abul Hashem and Alex Douglas (project leaders), Dr Mohammad Amjad, Dr Catherine Borger, Cameron Wild, Dave Nicholson, Barbara Sage.
Changes in farming systems and practices have had an impact on the weed spectrum on many Australian farms. Infestations of new and emerging weeds have increased costs and yield loss for growers.

In many cases, little is known about the biology of new and emerging weed species. It is important that we understand the mechanisms (changes in biology and ecology) behind the emergence and spread of these summer and winter weed species. It is also important to understand if they have developed resistance to our most commonly used herbicide, glyphosate, and develop alternative ways to control them.

Three projects, all the result of national collaborations will deliver new knowledge on the biology and management of summer and winter weeds, and investigate their resistance evolution to multiple herbicide modes of action.

Widespread development of herbicide resistance in many Australian weeds has increased the focus on integrated weed management (IWM) systems. IWM requires a greater level of information on weed biology, including information on the longevity and general behaviour of weed seedbanks under local farming systems.

Weeds of local importance are the focus of a project that commenced in 2016. It is likely that the weed species the study will focus on include marshmallow, matricaria and feathertop Rhodes grass.

Recent research outcomes include:

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  Button grass and tar vine are tough weeds that have a high level of dormancy. Finding ways to break seed dormancy is the key for future germination studies on these weeds.
  
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  Of nine sowthistle populations tested for resistance to glyphosate, three populations survived an application of 2L/ha Roundup Power Max. This indicates that these populations are already glyphosate resistant.
  
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  A weed survey of the WA grainbelt in late summer and early autumn of 2015 showed the most common roadside summer weed species were African love grass, fleabane, windmill grass and wild radish. The 2016 survey found 10 roadside infestations of feathertop Rhodes grass and one in-paddock infestation. In the eastern states, feathertop Rhodes grass is a serious weed species that has developed resistance to glyphosate.
  
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  At harvest, cutting the crop at 15 cm high removed 70% of brome grass seed, while almost no heads (or seed) of brome grass were removed if the crop was harvested at 35 cm high.
  

We will continue to investigate aspects of the biology and management options for new and emerging weed species. The weed survey will also continue into the 2016/2017 summer to give us greater understanding of the occurrence and movement of new weed species.