Sclerotinia infection in canola and lupin crops
Sclerotinia stem rot in canola
- Greenough
- Walkaway
Plant pathologist Ciara Beard (DPIRD) reports that sclerotinia stem rot has been found in two canola crops at Greenough and Walkaway this week. Last week there was leaf infection evident at both sites where no fungicide was applied and this week it has progressed to stem infection. The Hyola 404 crop at Greenough is at the end of flowering and most of the paddock has been sprayed with fungicide by the grower apart from where a DPIRD opportunistic trial is located. The trial has had a range of timings of fungicide application from 10% to 50% bloom to gather data to compare to the SclerotiniaCM app which has been run for each timing at the site. The stem rot symptoms are being seen in the untreated plots.
A similar experiment being conducted in a Raptor crop at Walkaway has similar symptoms and it is at 60% bloom. Both crops are dense and sown in paddocks that have a history of sclerotinia.
Growers and agronomists are encouraged to use the SclerotiniaCM app to assist decision making on whether to apply a fungicide spray during crop flowering this season. The free app is designed for ipads and android tablets and has been very helpful this year for prioritising paddocks to spray and indicating which ones may not be worthwhile spraying. Before applying fungicide for sclerotinia management growers need to follow guidelines on fungicide labels and ensure the crop is not beyond 50% bloom. For more information refer to DPIRD’s SclerotiniaCM app page.
Further information on sclerotinia management in canola can be found in previous 2020 PestFax Issue 12 Sclerotinia stem rot is being found in canola and Issue 8 Sclerotinia apothecia are being found articles.
Sclerotinia in lupins
- Narra Tarra
- Yandanooka
- Brookton
- Kojonup
Plant pathologist Ciara Beard (DPIRD) reports that sclerotinia infection of pods and branches was recently observed in an Albus lupin crop at Narra Tarra (near Geraldton). The Amira crop is dense, bulky and still flowering while filling pods after a great early start to the season. This area received significant rainfall in early May that most other parts of the Geraldton region missed out on. The grower applied fungicide to the crop at early pod emergence but left some unsprayed strips to gather disease development and yield data in conjunction with DPIRD. The disease symptoms are being seen in the unsprayed area.
Madi George (Mingenew Irwin Group) has recently found sclerotinia in an Albus lupin crop at Yandanooka (near Mingenew). The crop where a MIG and DPIRD in-crop fungicide demo is being conducted with the grower was previously reported in PestFax when apothecia were found under the crop earlier this month. Madi reports finding basal infection on the stem base at ground level on some plants that is causing them to appear wilted. There is also infection showing on pods on some plants, it appears as fluffy white growth.
David Stead (Anasazi Agronomy) has reported finding basal infection in a lupin crop east of Brookton. Capeweed plants in that corner of the paddock were also infected.
Chris Robinson (Farmanco) has reported observing sclerotinia in an Albus lupin crop at Kojonup. A foliar fungicide has been applied to this crop plus an adjacent narrow leafed lupin crop.
DPIRD research has shown that fungicide application prior to or at early stages of disease development can be effective for managing disease in the canopy. Trials have shown that fungicide application should be targeted at early pod emergence stage to protect the pods. However, fungicide is unlikely to provide any control of basal (stem base) infection due to the challenge of canopy penetration and the infection often being at and below ground level.
A list of registered fungicides and rates for lupin sclerotinia can be found at DPIRD’s Registered foliar fungicides for lupin in Western Australia page. It is important to follow label recommendations and observe withholding periods.
For information on the disease in lupin and managing it refer to the 2020 PestFax Issue 11 article Sclerotinia apothecia found in lupins.
For more information on sclerotinia stem rot contact DPIRD Plant pathologists Ciara Beard, Geraldton on +61 (0)8 9956 8504 or Geoff Thomas, South Perth on +61 (0)8 9368 3262
Article author: Ciara Beard (DPIRD Geraldton).