Australia
April 17, 2014
Northern growers looking to maximise their winter planting opportunities on the back of recent rain have been issued a stark warning over varietal selection, seed quality and purity – “you can’t manage what you don’t know.”
Industry leaders and researchers are urging growers to confirm variety quality through germination and vigour testing, ensure correct identification of seed prior to planting and match varietal maturity to planting window in a bid to avoid costly crop establishment, disease and agronomic management issues.
Grains Research and Development Corporation (GRDC) northern panel chair James Clark said consideration of these issues was critical if growers were to maximise crop establishment and yield potential.
“Germination and vigour testing helps growers to accurately assess the viability and vigour of seed to determine an appropriate seeding rate and maximise crop establishment,” Mr Clark said.
“Likewise, it is also very important that growers make sure that their sowing window corresponds with the maturity of their selected variety to maximise yield potential.
“We’ve also seen a couple of on-farm instances of incorrect identification in recent years which back the industry’s concern and research outcomes over seed purity.”
Research supported by the GRDC has proven that incorrect variety identification can cause a range of issues from incorrect sowing times and greater susceptibility to diseases like stripe rust to market downgrades over protein discrepancies.
All of these issues affect the yield and profitability of the crop due to factors such as the unnecessary application of fungicides, and make it extremely difficult for agronomists to give appropriate management advice.
Protecting variety purity is also a key priority for the industry as incorrect management jeopardises the resistance of individual varieties and industry confidence in resistance breeding for diseases like stripe rust.
The issue was highlighted in recent years with stripe rust outbreaks in the widely grown northern region cultivar Sunvale which NSW Department of Primary Industries (NSW DPI) cereal plant pathologist Dr Steven Simpfendorfer attributes to seed contamination rather than a breakdown in resistance genetics.
Genetic testing of 23 commercial Sunvale seed lots found that in 70 per cent of cases the lots contained rogue wheat varieties, all of which proved susceptible to moderately susceptible for stripe rust.
Pure Sunvale remains moderately resistant (MR) to stripe rust – a rating that was validated in the 2010 GRDC-supported National Variety Trials which found that Sunvale plots had very low levels of stripe rust development consistent with its MR rating despite a season highly conducive to stripe rust development.
Over the past three years the GRDC has invested heavily in the development of a new commercial DNA test to cost effectively identify the variety and purity of wheat and barley samples.
Varietal purity issues are not confined to wheat and barley crops, chickpea growers are also being warned that accurate identification of chickpea seed is critical to Ascochyta blight management in commercial crops.
NSW DPI plant pathologist Dr Kevin Moore said DNA evidence had identified genetic contamination in commercial chickpea crops going back to at least 2011.
“Chickpea varietal purity is a real issue and growers need to be confident in their seed source,” Dr Moore said.
“Growers can minimise the risk of contamination of their 2014 planting seed by obtaining seed from a registered seed merchant or if they are retaining their own seed, a quality control system should be put in place to avoid accidental contamination.”
Through a project supported by GRDC and NSW DPI, a seed testing service is now available for chickpeas enabling growers to test seed for pathology, germination and vigour at no extra cost.
Growers wanting to have chickpea seed tested should send 300-400g (two to three cups) of seed from each seed lot to: Kevin Moore, C/- Gail Chiplin, NSW DPI Tamworth Agricultural Institute, 4 Marsden Park Rd, Calala, NSW, 2340.
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