Australia
March 14, 2013
Leading plant pathologist Dr Kevin Moore, NSW Department of Primary Industries (NSW DPI), Tamworth is warning growers that complacency presents the biggest threat to northern chickpea crops this year.
Dr Moore says growers should be aware of the disease resistance traits of each variety they are growing and have seed tested for germination, vigour and pathogens.
“The first thing growers of any crop should do is make sure they’ve got good quality planting seed because getting crops off to a good start is dependent on the quality of the seed,” Dr Moore said.
“If they plant dodgy seed, crops will get off to a bad start.”
He says growers should source seed that germinates well (more than 70 per cent) and has little evidence of moulds or fungal pathogens.
Although last year’s spring and harvest period were dry, which augurs well for a low incidence of seed-borne diseases this year, Dr Moore advocates testing seed samples.
“It’s good insurance for growers who are using their own seed which has the equivalent value of about $600/tonne,” he said.
“You might get one shot at planting a chickpea crop and you want to get it right the first time.
“We recommend all planting seed is treated with a registered fungicide because it protects the plant not only from seed-borne pathogens but also from soil-borne pathogens and it’s relatively cheap.
Dr Moore delivered a paper at the Grains Research and Development (GRDC) Update at Goondiwindi, Queensland recently that outlined managing chickpea diseases in the 2013 season.
For some diseases such as Phytophthora root rot and viruses, there are no in-crop control measures and growers need to minimise the risk of these diseases now before planting, he said.
Dr Moore says for viruses which cause losses up to 60pc in some 2012 chickpea crops, the only strategies are agronomic:
- Retain standing stubble. Where possible, use precision agriculture to plant between stubble rows. It is believed this makes the crop less attractive to the aphids that transmit most chickpea viruses.
- Plant on time and at the optimal seeding rate – this results in a uniform stand and early canopy closure which reduce aphid attraction.
- Ensure adequate plant nutrition – healthy crops have less virus and less damage.
- Control in-crop, fence-line and fallow weeds which can be sources of vectors and viruses.
- Avoid planting adjacent to lucerne stands – lucerne is a perennial host on which legume aphids and viruses multiply and survive.
In 2012, the predominant chickpea virus was beet western yellows virus (BWYV). This virus was also found in every canola and mustard crop sampled in 2012. Consider growing chickpeas (and other pulse crops) away from canola and mustard.
There is no evidence that seed treatment or foliar sprays with insecticides are effective in reducing losses caused by viruses in chickpea crops.
The other major disease concerns for 2013 chickpea crops are Ascochyta blight, Phytophthora root rot and Botrytis grey mould, he said.
“Phytophthora root rot, which is a lethal disease in chickpeas, is also managed before you plant the crop through avoiding high risk paddocks and planting the most resistant varieties.
“Paddocks that are prone to waterlogging, are poorly drained, have a history of lucerne or medics or a history of Phytophthora root rot are high risk.”
Whether this is going to be a difficult season for botrytis grey mould will depend on conditions in spring; there’s nothing the growers can do about it at planting, he says.
“If it’s going to be a botrytis season in spring that will happen and growers will need to deal with it then.
“The one thing that they can do now is make sure they understand their ascochyta risk.”
Dr Moore said Ascochyta blight was not a concern in the northern grains region in 2012 except in central Queensland.
“However, the pathogen has been endemic in much of the region since 1998 and if conditions favour the disease it will pose a serious threat to susceptible varieties.
“Fortunately, growers have Ascochyta good management packages for the current varieties and the most recent varieties, those that have been released since 2005 and later, have quite useful resistances to Ascochyta which means growers don’t have to spend as much on fungicides.
“It also means that if they miss an Ascochyta fungicide spray the consequences of that missed spray are not as dire.”
Dr Moore says chickpeas have become a crucial part of cereal-based farming systems in the GRDC northern region.
“In fact some people might say wheat is now the rotation crop,” he says.
In 2010 the area planted to chickpeas in the northern region was 480,000 hectares but the crop was hit hard by disease and in the following year the planting area halved as first-time growers became cautious and quality planting seed was scarce.
In 2012, the area was back up to just under 500,000ha and would have been higher if seed stocks were more plentiful.
Dr Moore says the resurgence indicates growers are confident about the place the crop has in the farming system and they are equally confident about growing chickpeas.
“They know how to manage their key diseases and they know how to minimise the risk of those they can’t manage in-crop.”
For more information, visit www.grdc.com.au or to view video and download audio visit www.grdc.com.au/GRDC-MR-Clean-seed-and-care-the-recipe-for-chickpea-success
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