Disease management in high yielding Canola The West Australian experience. Rick Horbury Technical Advisor Western Australia

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1 Disease management in high yielding Canola The West Australian experience Rick Horbury Technical Advisor Western Australia

2 TOPICS (Onderwerpe) 1. Canola growing zones in Western Australia 2. Canola seed treatment fungicides in Australia 3. Blackleg (Leptosphaeria maculans) 4. Sclerotinia stem rot (Sclerotinia sclerotiorum) 5. Typical grower s program in High Rainfall Zone 6. Secondary diseases

3 WESTERN AUSTRALIAN CANOLA INDUSTRY - OVERVIEW Western Australia is the major canola growing state in Australia producing ~40% of the nation s 2.7 million tonnes each year. Majority of WA canola is exported generating about $700 million for the state s economy each year, into Asia for human consumption and Europe for biofuels. WA canola is renowned for its high oil content 2-4% compared to other states. (Premium paid of ~$7 per % over 42%)

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5 GRDC NATIONAL CANOLA SURVEY - DISEASE LOSSES Avg. annual value from Current management losses/ year Potential losses/ year Disease $/ha $ million $/ha $ million Blackleg Sclerotinia stem rot Downy mildew White leaf spot This represents a loss of 28.8% yield even with current measures or ~$133/ha. GRDC: The Current and Potential Costs from Diseases of Oilseed Crops in Australia Gordon M. Murray and John P. Brennan

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7 SEED TREATMENTS - FUNGICIDES Trade name Active ingredient registered claims Use rate Product type Resistance Group Jockey Stayer fluquinconazole blackleg 2000 ml/100 kg Seed treatment 2 Granule fertiliser or Intake flutriafol blackleg 400 ml/ha liquid banded 2 EverGol Extend Maxim XL penflufen + trifloxystrobin (fludioxonil + metalaxyl-m) fusarium & rhizoctonia 65 ml/100 kg Seed treatment blackleg (s), pythium & rhizoctonia 400 ml/100 kg Seed treatment

8 BLACKLEG (Leptosphaeria maculans) - MANAGEMENT 1. Stubble borne spread by wind 2. Cultural -Crop rotation (1 in 3 OK but spores can travel a distance) - Later sowing will favour spore maturity & disease 3. Variety and resistance group selection 4. Seed treatment or infurrow fungicides 5. Foliar fungicides Like England just when you think you have it worked out it comes back and beats you!

9 BLACKLEG MANAGEMENT ROTATE RESISTANCE GROUPS If Groups A & B are main resistance groups used in TT canola what does this mean long term?

10 BLACKLEG Increased tolerance carries through to stem canker formation % Stem canker Bare Jockey Normal isolate Fungicide tolerant isolate Grains Research Update in Bendigo, 23 & 24 February 2016

11 BLACKLEG AUSTRALIAN POPULATIONS TOLERANT TO FLUQUINCONAZOLE Blackleg may be currently managed in SA now but keep an eye on it! # samples % of population (# paddocks) State submitted No tolerance Low tolerance Tolerance VIC (30) 26 (13) 14 (7) SA (25) 23 (10) 17 (7) NSW (36) 26 (17) 20 (13) WA (32) 17 (7) 7 (3) Total (123) 23 (47) 15 (30) No tolerance Low tolerance High tolerance Grains Research Update in Bendigo, 23 & 24 February 2016

12 BLACKLEG MANAGEMENT FOLIAR FUNGICIDE IN HIGH RISK

13 BLACKLEG MANAGEMENT ONLINE DISEASE RISK TOOLS THE PROSARO SCALE For: Blackleg and Sclerotinia Stem Rot WEATHER DATA: Linked to all Australian post codes BLACKLEG MODEL Proven model from DAFWA - predicts the date of blackleg spore release The Prosaro scale calibrates the date and gives a warning rating SCLEROTINIA MODEL Proven European model tailored to Australian conditions and rotations The Prosaro scale utilises real time data and predicts infection risks

14 SCLEROTINIA (Sclerotinia sclerotiorum) - MANAGEMENT 1. Soil borne disease spores travel local distances (paddock to paddock) 2. Cultural Crop rotation (1 in 3 rotation has shown to still be too short) Early sowing favours peak flower in wet months & disease 3. Variety There are no tolerant varieties in Australia 4. Seed treatment or infurrow fungicides are inneffective 5. Some success has been had with wider row spacing or low seeding rates but this comes at a cost to yield potential. 6. Foliar fungicides are the only option but work best PROACTIVELY

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16 SCLEROTINIA (Sclerotinia sclerotiorum) QUICK FACTS Sclerotes survive for long periods in the soil (~6 years). i.e. a 1 in 3 years rotation will reduce but not eliminate risk. All broadleaf crops and pastures are hosts. (Koring = a break crop ) A single sclerote can produce up to 15 apothecia. All canola varieties are susceptible and bigger healthier canopies can increase the risk. (High fertiliser programs can ^severity) Main stem infections cause greater yield loss than lateral ones. Canola in Australia flowers for ~6-8+ weeks depending on variety but a spray offers ~3 weeks protection. ~Every 1% of plants infected = 0.5% yield loss

17 SCLEROTINIA Critical points for disease development. Soil temperature ~15 C with full moisture profile Apothecia will emerge after ~7-10 days and will keep emerging while conditions are favourable (high humidity). 18 hours of continual leaf wetness will allow a sclerotinia spore to infect the leaf. Rain/ dew days count most through flowering, Days of canopy wetness count more than the actual mm once the soil profile is full prior to flowering. Optimal temperature for lesion development is above 20 C Primary infection generally from petals or soil contact Secondary infection can occur from contact with infected leaves or stems.

18 SCLEROTINIA Stages of disease frequency & pressure. ENDEMIC: Consistent economic losses (30%+ infection) History and rotational experience of disease Sclerotes present in the paddock at high levels Apothecia emerge every year in crop Adjacent paddocks also have high incidence Leaf lesion (Petal infection) frequency is high Plant to plant (leaves, stem) infection is high and not uncommon to see infection initiating between contacting leaves First sprays crucial at ~20% flower and likely to warrant a 2 spray strategy in a season above 1.5 t/ha yield potential. MODERATELY ADJACENT (0-10% infection) Paddock has had no disease observed previously. Apothecia can t always be found. Adjacent paddocks with previous history within m Leaf lesion frequency low to moderate. Disease may initiate under ideal conditions most likely during mid flowering Spray economics dependent on conditions and yield potential HIGHLY ADJACENT (10-30% infection) Paddock has had low disease previously and/or adjacent paddock ( m) has had high levels Sclerotes may be present in the paddock at low levels? Apothecia found easily in adjacent paddock of cereal with previous history but hard to find in crop Leaf lesion frequency may be moderate to high but disease will initiate under ideal conditions Plant to plant infection occurs as primary infection takes off A well timed single spray from 20-50% will most likely be economic with potential second application under high pressure LOW RISK No history in area. Apothecia can t be found. Low rainfall region with extended dry periods and open low yielding canopies. Economic response unlikely A single spray at 20-50% may be required under conducive conditions to prevent paddock building an http: or Think twice Sclerotinia endemic sclerote bank in the soil.

19 SCLEROTINIA ENDEMIC disease development, Moonyoonooka WA 2014 ~3/7 ~2-5% flower First apothecia emerged in adjacent crop (hard to find) as wheat canopy fills in, 10/07 ~15% flower. Apothecia in adjacent wheat crop several days old with more emerging. Leaf infection commenced at low levels. 23/7 ~30% flower. Apothecia levels high in adjacent wheat and also found in canola paddock. Leaf infection occurring, first signs of leaves turning mouldy. 31/07 ~50% flower. First apothecia emergence finished, fresh emergence coming through. Leaf lesions common with first sign of stem infection. Significant stem infection seen within 3 weeks of apothecia emergence

20 Assessment of flowering stages Flowering stages should be assessed on the main stem: 10% = 10 flowers open 20% = flowers open 30% = 20 or more flowers open 40% = 30 or more flowers open 50% = All flowers are open or have opened, crop is at its most intense yellow (full flower) 60% = Flowering intensity is beginning to decline

21 SCLEROTINIA MANAGEMENT ONLINE DISEASE RISK TOOLS

22 Year, Location Mean 13 Henty (NSW) 12 Dookie (Vic) 13 Wagga Wagga 12 Dookie (Vic) 12 Chapman Valley (WA) 12 Howlong (Vic) 11 Howlong (Vic) 15 Chapman Valley (WA) x 2 spray 12 Alma park (NSW) 14 Pingelly (WA) 14 Williams (WA) 14 Gt Southern (WA) 13 Junee (NSW) 15 Esperance (WA) x 2 spray 12 Dookie (Vic) 14 Gt Southern (WA) 14 *Bolgart (WA) 11 Rudd's Gully (WA) 11 Chapman Valley (WA) 11 Chapman Valley (WA) 14 *Gibson (WA) 13 Chapman Valley (WA) 13 Green Range (WA) 11 Strawberry (WA) 13 Tarcutta (NSW) 14 Moonyoonooka (WA) 14 *Moonyoonooka (WA) 12 Boorowa (NSW) 13 Cowra (NSW) 13 *Narngulu (WA) 13 Henty (NSW) 12 Holbrook (NSW) 12 Dookie (Vic) 12 Burrumbuttock (NSW) 14 Geraldton (WA) x 2 spray 14 West Narrogin (WA) 14 West Narrogin (WA) 13 Walbundrie (NSW) % untreated yield Prosaro control of sclerotinia in canola, Australia Average % yield increase over untreated (100% = 1.83 t/ha) 22% average yield increase (350 kg) over untreated across 38 trials

23 SCLEROTINIA Field experience in Western Australia 2016 Disease development Early sowing dates through April or even late March means flowering coincides with wettest months. ~10 days from significant apothecia emergence in crop to high incidence and severity leaf infection. Peak infection evident ~3 weeks after significant apothecia emergence with stem rot commenced. Adjacency to previous trouble spots is critical or 2014 canola stubbles worst affected. Lupin and fallow pasture paddocks with Cape weed (Arctotheca calendula) in 2015 Disease found very early pre significant flowering in fallow pasture paddocks or lupins in 2015 in the high rainfall zone Sclerotinia geography has significantly increased (~30% of planted area) We have diseased crops throughout the entire high rainfall zone and areas of the medium rainfall zone now

24 Getting the best results for sclerotinia in canola The checklist: Don t apply too early - check for apothecia in the area. Single spray: ENDEMIC: ~20-30% flowering dependent on conditions. ADJACENT: 30-50% flowering. Multiple Sprays under high disease pressure or early sowing: ENDEMIC: 20 & 50% under high disease pressure Longer flowering varieties in the Great Southern. Other considerations: Temperature and rainfall are more important than flowering stage. 100 L/ha+ water rate. Faster growing plants = shorter window of protection due to growth dilution. Future developments: Aviator Xpro will be registered for use in canola in the 2016 season.

25 High Yielding grower Barry Clarke West Bolgart WA 429 mm mean rainfall at Wattening nearby

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27 CANOLA SECONDARY DISEASES White leaf spot and Downy mildew are both sporadic and very seasonal Like Japanese rugby they normally don t cause an issue!

28 Thanks for listening Dankie vir die luister

29 CANOLA WHITE LEAF BLISTER (Pseudocercosporella capsellae) Symptoms Greyish-white to light-brown leaf lesions up to 10mm diameter often with a brown rim. Lesion can merge and lead to premature defoliation and spread to upper leaves and less commonly, stems and pods Disease cycle Stubble borne After prolonged wet weather in autumn/winter,wind-borne spores are produced that cause primary leaf lesions on canola. These initial lesions produce new wind and rain-borne spores that cause the rapid spread of the disease throughout the crop. Not usually seed-borne but can be spread by infected seeds or infected debris with the seed. Management strategies Rotation White leaf spot infection is not usually severe enough to warrant control. Control brassica weeds Crop rotation and isolation from the previous year s canola stubble

30 CANOLA DOWNY MILDEW (Peronspora parasitica) Symptoms Yellow areas on the upper leaf surface is the first symptom. These can be seen on young seedlings when cotyledons or first true leaves are present. A white powdery fungal growth can be seen on the underside of the leaf beneath these spots. Disease cycle Downy mildew is both soil and seed-borne and can persist in the soil for a long time. Infection is favoured by cool wet weather and under ideal conditions, new infections can develop in as little as 3 to 4 days. Management strategies Rotation Infection is not usually severe enough to warrant control. Control brassica weeds Crop rotation and isolation from the previous year s canola stubble