Keep up with the latest research information on Pulse diseases including ascochyta, phytophthora, root lesion nematode and viruses. The following papers were presented at the GRDC Updates across Australia in February and March 2015. There were no papers presented in the Western region.
By Jenny Davidson, Rohan Kimber (SARDI Pulse Pathology), Christine Walela, Larn McMurray (SARDI New Variety Agronomy), Kristy Hobson (NSW DPI), Jason Brand (Vic DEDJTR) and Jeff Paull (Adelaide University). Presented at Adelaide, February 2016.
- Ascochyta blight has been observed on Genesis™090 chickpeas in South Australia (SA) and Victoria. Foliar fungicides will be necessary in this variety to prevent yield loss. In controlled conditions Genesis™079, Ambar and Neelam demonstrated resistance to these new isolates although this result needs to be confirmed in field trials. Chickpea crops should be monitored for resistance breakdown and any anomalies reported to SARDI
- Monitoring of Ascochyta blight of lentils and faba beans confirmed the loss of resistance in Nipper lentils across SA and Victoria, and the loss of resistance in Farah and partial loss of resistance in PBA Rana faba beans in the Mid North of SA. These cultivars will require fungicide protection particularly against pod and seed infection in wet springs. Lentil and faba bean crops should be monitored for resistance breakdown and any anomalies reported to SARDI. Intense cropping of a single dominant cultivar risks the loss of further resistance genes in these crops
- Growers choosing to sow field pea into high risk periods predicted by the Blackspot Manager must implement best practice to reduce losses from the disease, or consider an alternative break crop field pea
- Traffic damage and delayed harvest timing can reduce faba bean seed quality. Choosing new faba bean varieties with superior seed characteristics reduces the potential of crop topping, windrowing and traffic damage affecting seed quality
- Fungicide regulations: a small number of registered chlorothalonil products have label instructions that allow for grazing. Pulse Australia have secured permits for Amistar®Xtra, Prosaro®420SC and Captan® to control Ascochyta blight and/or botrytis grey mould on chickpeas and lentils until June or September 2018
By Kurt Lindbeck (NSW DPI). Presented at Wagga Wagga, February 2016.
- Consider previous herbicide use, crop rotation history, soil type (including pH) and paddock location when deciding to sow a pulse crop. As these factors can influence crop performance and disease risk
- Not all pulse diseases can be managed with foliar fungicides, consider other management options when sowing pulse crops
- Foliar disease management is integral to growing faba bean. Understand the critical periods for disease management and foliar fungicide selection
By Kevin Moore, Kristy Hobson, Nicole Dron, Steve Harden and Sean Bithell (DPI NSW), Prabhakaran Sambasivam (Uni of Melbourne), Rebecca Ford, Yasir Mehmood (Griffith Uni), Jenny Davidson (SARDI), Shimna Sudheesh and Sukhjiwan Kaur (Agribio DEDJTR).
- In 2015, Ascochyta blight occurred in a higher proportion of chickpea crops (60 of 243 crop inspections) than in 2014 (62 of 332 crop inspections). Most infected crops were PBA HatTrick which was also the most commonly grown variety.
- Work to determine if the Ascochyta pathogen is changing started in 2013, where a number of projects are working together to provide an integrated approach to chickpea Ascochyta blight to improve variety resistance and best management practices.
- Initial results show that the population varies in time for spore germination, germ tube length, ability to cause disease (pathogenicity), and time to develop fruiting bodies (latent period).
- Significant differences in the reaction of some varieties and advanced breeding lines to two aggressive isolates of the AB pathogen have been found
- It is essential that growers adhere to best management practices, such as sustainable rotations, to minimise selection pressure on the pathogen and maximise the longevity of variety resistance.
- While research into variability of the AB pathogen continues, it seems prudent to adopt a conservative approach to AB management
Please see Updated advice for chickpea Ascochyta and Botrytis Grey Mould management for the Northern Region
By Kevin Moore, Leigh Jenkins, Paul Nash, Gail Chiplin and Sean Bithell, Department of Primary Industries, NSW
- Plant seed of known identity and purity and of high quality that has been properly treated with a registered seed dressing.
- Localities where Ascochyta was found on any variety in 2015 are considered high risk for 2016 crops and growers are advised to apply a preventative fungicide before the first post-emergent rain event to all varieties including PBA HatTrick .
- Mild temperatures, long cloudy periods and frequent rainfall events during Jun/Jul across the Northern region as occurred in 2015, are ideal for early season outbreaks of Ascochyta blight in chickpea crops.
- In wet seasons the management of Ascochyta can be hindered by getting ground rigs into wet paddocks and shortage of fungicides.
- Follow the disease management recommendations in this article and associated links – they will maximise your chance of a profitable chickpea crop in 2016.
By Kevin Moore, Kristy Hobson, Steve Harden, Gail Chiplin and Sean Bithell (NSW DPI), Lisa Kelly, Willy Martin and Kris King (DAFQ)
- In a wet season, substantial (94%) yield losses from PRR occur in susceptible varieties such as PBA Boundary. Do not grow PBA Boundary if you suspect a PRR risk
- Varieties with improved resistance to PRR (PBA HatTrick and Yorker) can also have large yield losses (68-79%) in a very heavy PRR season
- Although yield losses will occur in very heavy PRR seasons, crosses between chickpea and wild Cicer species such as the breeding line CICA1328 offer the best resistance to PRR
- Avoid paddocks with a history of lucerne, medics or chickpea PRR
Effect of chickpea ascochyta on yield of current varieties and advanced breeding lines – the 2015 Tamworth trial VMP15
By Kevin Moore, Kristy Hobson, Steve Harden, Paul Nash, Gail Chiplin and Sean Bithell (NSW DPI).
- Under extreme disease pressure, Ascochyta can be successfully and economically managed on susceptible varieties such as Kyabra and Jimbour.
- However, Ascochyta management is easier and more cost effective on varieties with improved resistance eg PBA HatTrick and PBA Boundary.
- The 2015 Ascochyta trial, VMP15, confirmed the next variety planned for release (CICA0912) has excellent resistance to Ascochyta.
By Sean Bithell, Kevin Moore, Kristy Hobson and Steve Haden (NSW DPI), Willy Martin (DAFQ) and Alan McKay (SARDI)
- Increasing level of inoculum (oospores/plant) of Phytophthora medicaginis (Pm) was strongly correlated with decreasing yield of the moderately resistant variety Yorker
- An inoculum level of 660 oospores/plant (PreDicta B® > 5000 Pm copies/g soil) at sowing significantly reduced yields compared with lower inoculum levels under both dryland and irrigated conditions
- Testing soil samples from growers’ 2015 paddocks confirmed the results of testing 2014 samples that the PreDicta B® soil Pm test can identify Pm in growers paddocks in NSW and QLD
- These findings provide further evidence that the PreDicta B® Pm test will be a useful tool for growers to determine their risk of Phytophthora root rot
- Note: the SARDI PreDicta B® test for Phytophthora medicaginis is under development and is not yet available commercially
By Kevin Moore, Kristy Hobson and Sean Bithell (NSW DPI). Presented at North Star and Goondiwindi, March 2016.
- Planting your 2016 chickpea crop into paddocks that had chickpeas in 2015, or earlier, is risky and you could lose money.
- Further, it puts current disease management practices under pressure and could lead to reduced life of chickpea varieties, development of fungicide resistance and problems with weeds and insects.
- Growers are urged to follow recommendations for current best practice especially with regard to crop rotation.