Australian postharvest sanitation and fungicide resistance survey

Transcription

1 Australian postharvest sanitation and fungicide resistance survey Survey results from the Australian Citrus Postharvest Science Program (CT15010) John Golding. NSW Department of Primary Industries

2 Postharvest decay control Postharvest decay control must use a range of complementary strategies: + correct harvesting and handling + shed hygiene + correct use of sanitisers + use of fungicides just one component of decay management + temperature management + monitoring inoculum levels and fungicide resistance

3 Postharvest decay control Requires an integrated approach don t rely on fungicides alone Correct harvesting + handling Spore exclusion + sanitation Use Of sanitisers Temperature management Use of fungicides Monitoring inoculum levels + fungicide resistance

4 Current fungicides - control of blue and green mould Thiabendazole (TBZ) Imazalil Imazalil + Pyrimthanil Fludioxonil Propiconazole + Fludioxonil Vorlon, Tecto Benzimidazole Group (activity also on Stem End Rot, Phomopsis citri) Magnate, Fungaflor DMI (Demethylation Inhibitors) (Imidazole) Philabuster DMI and Anilinopyrimidine Group Scholar Phenylpyrrole Group (activity also Diplodia Stem End Rot) Chairman DMI and Phenylpyrrole Group GROUP 1 FUNGICIDE GROUP 3 FUNGICIDE GROUP FUNGICIDE GROUP 12 FUNGICIDE GROUP FUNGICIDE Preventol ON Fungicide (controls blue mould only) (sodium ortho-phenylphenate)

5 Current fungicides Control of sour rot Guazatine Zanoctine, Panoctine Multi-site activity (Guanidine) (activity also on blue and green mould) ** Note that guazatine is not allowed in some export markets ** GROUP M7 FUNGICIDE Fludioxonil + Propiconazole Chairman Phenylpyrrole Group and DMI GROUP FUNGICIDE Sodium bicarbonate can control sour rot

6 Issues with fungicides Cost Disposal / waste Correct application rates (monitoring and measuring) and methods Fungicide resistance issues Compatibility with sanitisers, waxes etc Maximum Residue Limits (MRL) Domestic Export

7 Fungicide resistance

8 Fungicide resistance Resistance occurs in well-used fungicides (eg TBZ and imazalil) which causes major losses if not properly managed Risks: Fungicide-treated fruit are stored for long time Similar fungicides used on same fruit during packing Pathogens produce lots of spores = shed hygiene Fungicides which have a single-site mode of action (eg TBZ and imazalil) Fungicide resistance = $$$

9 Fungicide resistance survey Survey of shed sanitation and resistance to postharvest fungicides across Australia from May to September 2018 (follow on from previous June/July 2017) New South Wales Queensland South Australia Victoria Western Australia Test resistance to common postharvest fungicides (TBZ, imazalil and fludioxonil) 3 locations in shed: (1) start of the line, (2) end of the line and (3) coolroom

10 Fungicide resistance survey - example

11 Fungicide resistance survey - example Untreated (#colonies) TBZ resistance Imazalil resistance Fludioxonil resistance Shed 1 Shed 2 Start End Coolroom Start End Coolroom very low very low very low high high high very low very low very low very low low very low very low very low very low very low very low very low

12 2018 Fungicide sanitation and fungicide resistance survey results NSW Untreated TBZ Imazalil Fludioxonil Shed S E C T S E C T S E C T S E C T NSW A NSW B NSW C NSW D NSW E NSW F NSW G NSW H NSW I Average

13 2018 Fungicide sanitation and fungicide resistance survey results Queensland Untreated TBZ Imazalil Fludioxonil Shed S E C T S E C T S E C T S E C T Qld A Qld B Qld C Qld D Qld E Qld F Qld G Qld H Qld I Average

14 2018 Fungicide sanitation and fungicide resistance survey results Victoria Untreated TBZ Imazalil Fludioxonil Shed S E C T S E C T S E C T S E C T Vic A Vic B Vic C Vic D Average

15 2018 Fungicide sanitation and fungicide resistance survey results Western Australia Untreated TBZ Imazalil Fludioxonil Shed S E C T S E C T S E C T S E C T WA A WA B WA C WA D WA E Average

16 2018 Fungicide sanitation and fungicide resistance survey results South Australia Untreated TBZ Imazalil Fludioxonil Shed S E C T S E C T S E C T S E C T SA A SA B SA C SA D SA E SA F SA G SA H SA I SA J SA K SA L SA M SA N SA O SA P Average

17 2018 Fungicide sanitation and fungicide resistance survey results Follow-up after sanitation and hygiene improvements No fungicide - control Before Start End Coolroom After Start End Coolroom +TBZ Start End Coolroom Start End Coolroom

18 2018 Fungicide sanitation and fungicide resistance survey results Follow-up after sanitation and hygiene improvements 1. Initial reading 2. After cleaning Untreated TBZ Imazalil Fludioxonil Shed Time S E C T S E C T S E C T S E C T A A B B C C

19 Reducing fungicide resistance Management of fungicide resistance requires an integrated approach: 1. Optimise fruit health 2. Use best hygiene practices 3. Optimise fungicide use 4. Optimise fungicide efficacy 5. Monitor fungicide resistance

20 Reducing fungicide resistance 1. Optimise fruit health good postharvest practices Minimise physical damage to the fruit - most postharvest decay fungi can only infect through wounds in the peel = less decay Australian Citrus Harvest Handbook = guidelines on the correct harvest and handling of citrus Limit storage of the fruit and keeping fruit at the optimal storage temperatures = reduces the ageing of the fruit and therefore its susceptibility to decay

21 Reducing fungicide resistance 2. Use best hygiene practices good postharvest hygiene Reduce numbers of decay-causing spores in the shed, cool room and on the fruit = reduced risks Remove all culled and especially decaying fruit from the shed Regular sanitation of equipment (including picking bins), cool rooms and packing line Ideal to have a separate area of receivals of fruit to the packing line Good shed hygiene

22 Reducing fungicide resistance 3. Optimise fungicide use rotate different fungicides with different actions Understand the class of fungicide you are using and limit the total number of fungicide applications of any one class. = the continued use of the same fungicide class can cause selection pressures resulting in resistance Use rotations and mixtures or pre-mixtures whenever possible before resistance selection occurs Use the label rate for each fungicide - lower rates of fungicide can select for less sensitive spores in the population

23 Reducing fungicide resistance Thiabendazole (TBZ) Vorlon, Tecto Benzimidazole Group (activity also on Stem End Rot, Phomopsis citri) GROUP 1 FUNGICIDE Imazalil Magnate, Fungaflor DMI (Demethylation Inhibitors) (Imidazole) GROUP 3 FUNGICIDE Imazalil + Pyrimthanil Fludioxonil Propiconazole + Fludioxonil Philabuster DMI and Anilinopyrimidine Group Scholar Phenylpyrrole Group (activity also Diplodia Stem End Rot) Chairman DMI and Phenylpyrrole Group GROUP FUNGICIDE GROUP 12 FUNGICIDE GROUP FUNGICIDE Preventol ON Fungicide (controls blue mould only) (sodium ortho-phenylphenate)

24 Reducing fungicide resistance 3. Optimise fungicide use rotate different fungicides with different actions Understand the class of fungicide you are using and limit the total number of fungicide applications of any one class. = the continued use of the same fungicide class can cause selection pressures resulting in resistance Use rotations and mixtures or pre-mixtures whenever possible before resistance selection occurs Use the label rate for each fungicide - lower rates of fungicide can select for less sensitive spores in the population

25 Reducing fungicide resistance 4. Optimise fungicide efficacy use fungicides properly Fungicide coverage determines the efficacy of the treatment and minimises the chances of decay spores surviving following treatment Use of sanitisers and alkaline salts in the packing line to kill pathogens Sanitisers have a broad method of killing fungi, and resistance to these chemicals is unlikely

26 Reducing fungicide resistance 5. Monitor fungicide resistance can only improve postharvest practices by monitoring Routinely monitor pathogen populations = the early detection of potential resistance increases the chance that its development can be managed Routine hygiene monitoring helps knowing that sanitation and cleaning programs are working

27 More information Regular updates in Australian Citrus News Postharvest decay control - fungicides and sanitisers Management change can reduce fruit decay Preventing postharvest fungicide resistance

28 Australian Citrus Postharvest Science Program (CT15010)

29 Future fungicide resistance activities Hort Innovation Postharvest Project (CT15010) will no longer conduct this survey. The Project will focus on other postharvest and market access R&D activities A cost-recovery service will be available for growers and packers in 2019 season Citrus Australia and NSW Department of Primary Industries partnership The service is currently being finalised and will be cost-recovery (not for profit) service for industry. Details will be available soon

30 Australian Citrus Postharvest Science Program John Golding Center of Excellence for Horticultural Market Access NSW Department of Primary Industries Ourimbah NSW Telephone