1. Reducing postharvest brown rot problems - a systems approach

2. Booklet BMPs for brown rot (2015)
Resources
Brown rot control – project SF12004
Booklet BMPs for brown rot (2015)
Summerfruit – HIA (2015)
Summerfruit - HIA (2015)

3. Best practices to reduce postharvest brown rot (a systems approach)
Know the disease risk factors
Effective pre-harvest control
Determination of rot risk at harvest
Effective postharvest management

4. Know the disease risk factors
Block history (disease carry-over)
Climatic conditions
Crop susceptibility
Stage of fruit maturity
Fruit injuries increase susceptibility

5. Orchard sanitation key to reduce brown rot problems
Phases of brown rot
Sources of spore for infection
Twig blight
Blossom blight
(latent infection)
Fruit rot
Orchard sanitation key to reduce brown rot problems
Post-harvest brown rot

6. Fruit susceptibility to Monilinia infection (fresh market)
Flowers & fruitlets susceptible
Ripe fruit susceptible
Immature fruit least susceptible around pit hardening
Injury increases fruit susceptibility
Kreidl, Edwards, Villalta (2015). APPJ

7. Monilinia spore infection requirements (Brochure)
Kreidl, Edwards, Villalta (2015). APPJ

8. Strategies for blossom blight and pre-harvest fruit brown rot control
well-timed application of protectant and post-infection fungicide sprays
apply according to infection risk (ie spore infection risk and crop susceptibility)
more targeted (risk-based) spray programs
low disease blocks
high disease blocks (ie late season cultivars)

9. Factors to consider in risk-based spray programs
Sanitation to reduce inoculum
Infection risk high (blossom blight & young fruit): aim prevention
primary infection
Pre-harvest: risk very high ripe fruit
Infection risk in green fruit depends on: weather, fruit injury, disease pressure, etc.

10. Effect of fungicide treatments on blossom blight incidence

11. Blossom blight control
integrate orchard sanitation, infection risk prediction and fungicide sprays
2-3 sprays required from 5% bloom, then full bloom (i.e. 80% bloom) to shuck-fall, adjusted as per infection period frequency and fungicide efficacy
A preventive approach is more effective than relying on post-infection treatments

12. Efficacy of x2 pre-harvest fungicide sprays on fruit brown rot control
Late season nectarine, Victoria
Crop stage
Untreated
With Tilt
With Fontelis
With BASF P
With Luna Sensation
With Syngenta P
Bloom-shuck fall
No sprays
Chorus, Sumisclex, Syllit
Chorus, Fontelis, Syllit
Chorus, BASF P, Syllit
Chorus, Bayer P, Syllit
Chorus, Syngenta P, Syllit
Green fruit
Thiram
Pre-harvest
No spray
Tilt x2
Fontelis x2
BASF P x2
Bayer P x2
Syngenta P x2
Please notice: BASF P, Syngenta P and Bayer P are NOT registered for stone fruit in Australia

13. EXAMPLE ONLY - PLEASE READ THE LABEL BEFORE USING FUNGICIDES
Example of fungicides used in commercial trials in stone fruit (fresh market) orchards during
Tactics
Bloom - shuck fall
Post-bloom
30-50 days
Pit hardening
Pre-harvest
3-4 weeks
Post-harvest
Example existing fungicides*
Chorus
Sumisclex
Syllit
Thiram
Tilt, etc
Ziram
Mancozeb, etc
Tilt
Saprol, etc
Scholar
Other?
New chemistry (MRL issues?)
Fontelis Luna Sensation _
Fontelis, Luna Sensation
Spray interval?
7-10 days interval
14-30 days interval or as per rain
1-14 days interval
* To prevent overuse, Tilt used preferably preventively or for post-infection ONLY when necessary?
EXAMPLE ONLY - PLEASE READ THE LABEL BEFORE USING FUNGICIDES

14. Example typical spray program in blocks with brown rot problems (e. g
Example typical spray program in blocks with brown rot problems (e.g. late season cv)
Sprays (black symbols) applied preventively before infection periods of low and high infection risk severity during flowering-shuck fall (pink), post-bloom (light green), post-pit hardening (green) and pre-harvest (red).
This spraying strategy can be adjusted according to site disease pressure (i.e. over-wintered inoculum and crop susceptibility) and stages of fruit susceptibility.
Always read the label before using a fungicide product.

15. Example spray program in a block with early season cv with low brown rot pressure
Mummies = 0% blossom blight = 0% green fruit = 0% brown rot = 0%
Fungicide program
Copper
Ziram
Sillyt
Tilt
Thiram
Saprol

16. Example spray program in a block with late season cv with history of brown rot problems
Mummies = 2 m2 blossom blight = 0% green fruit = 0% brown rot = 7.5%
Standard Treatment
Copper
Chorus
Sumisclex
Syllit
Thiragranz
Tilt

17. Management of pre-harvest brown rot
If weather wet and disease pressure high (e.g. spores around and fruit injury) – fruit must be protected with fungicides (ie 7-14 days intervals as per product efficacy)
Benefits of pre-harvest sprays:
inhibit sporulation of existing infections
protect fruit from new infections
reduce inoculum preventing more infections

18. Risk of brown rot at harvest and postharvest
Risk fruit rots at harvest:
infections initiated early season (latent)
infection during the fruit ripening period
Risk fruit rots postharvest:
quiescent (latent) infection in ripe fruit
spores contaminating fruit surfaces
spores in flumes and dump tank
post-harvest decay fungi infect tissue mostly through wounds but also healthy tissues

19. Integrated postharvest control of brown rot and other decay-causing fungi
Management most effective using integrated strategy that includes:
pre-harvest fungicide sprays (inhibit infections at harvest)
determination of fruit infections (latent) at harvest
post-harvest fungicides (protect fruit from infections)
effective post-harvest sanitation decay control practices

20. Determination of fruit infection (latent) at harvest
Incubate fruit under moist conditions at room temperature (18-25°C)
Assess fruit rot levels after 5-7 days incubation
Collect min. 120 fruit per block (1 ha) 7 days before harvest

21. Estimate overall rot risk at harvest to develop a postharvest and market strategy
Overall rot risk: integrate orchard information (spray dairy, insect pressure, block history) with measured fruit rot levels
Subsequent post-harvest handling practices will influence the overall risk!
Infected fruit require post-harvest treatment
Disease-free fruit for premium markets!

22. Effect of post-harvest treatments on brown rot control (fruit held for 10 days at 0°C and then 10 days at 20°C)
x3 pre-harvest sprays + post-harvest treatment (Autumn Snow peach)
x1 pre-harvest spray + post-harvest treatment : Arctic Snow nectarine

23. Control of blue mold wound infection by Scholar (apples)
Fruit wound-inoculated with Penicillium spp.
Fruit dipped in various fungicide treatments
Fruit stored for 2-3 weeks room temperature

24. Best postharvest practices to reduce decay-causing organisms
harvest fruit at right time, avoid injuries and cool quickly
store fruit optimum temperature to retard ripening/softening
remove plant pathogens from equipment with effective sanitisers
sanitisers kill microorganisms and spores suspended in water but they often do not protect wounded tissue against subsequent infection from spores lodged in wounds

25. Disinfestation activity of some postharvest treatments
Delivery system
Disinfestation Activity
Chlorine
water
fruit surface/in solution
Ozone
water/air
water poor solubility
in air/antisporulation
Scholar fungicide*
wound protection
*export MRLs concerns
Always read the label before using a fungicide product.

26. Are there effective alternatives to post-harvest fungicides?
few products available with wide spectrum fungicidal activity
alternatives are often less effective than fungicides
biocontrols inconsistent control – compatibility issues with chemicals!
high calcium content known to help reduce incidence fruit rots
Key considerations when selecting post-harvest treatments:
efficacy (pathogen type in the fruit and decay)
location of pathogen in the fruit,
is it a wound or contact protection product?

27. Acknowledgements
HIA, Summerfruit Australia and DEDJTR for funding the research
Team: Oscar Villalta, Robert Holmes, Simone Kreidl,
Collaborators: Jacky Edwards, Kim Plummer, Phil Keane, Hu Baishi, Belen Guijarro, Chin Gouk, M. Hossain
Many fruit growers in Renmark, Swan Hill, Cobram and Bangalow for collaborating with field trials

28. Thanks

29. Example of spectrum of activity of registered or proposed post-harvest fungicides in the USA
Class
Crops
Fungi/decay
Fludioxonil
Phenylpyrrole
Stone fruit
Pome fruit
Brown rot, Gray mold, Rhizopus rot, Penicillium decays
Fenhexamid
Hydroxyanilide
Stone fruit, pome fruit
Brown rot, Gray mold
Pyrimethanil
Anilinopyrimidine
Brown rot, Penicillium decay, Gray mold
In Australia, fludioxonil,thiabendazole, iprodione and imazalil have been available for post-harvest control of fungal rots of pome fruit
Always read the label before using a fungicide product.

30. Management of pre-harvest and post-harvest brown rot (continuation)
Benefits of sanitation post-harvest practices:
maintain good sanitation to reduce spore levels available for infections
harvest correct maturity for storage and reduce injuries
use correct storage temperature to stop growth of target fruit rot fungi and slow decay development

31. Management of pre-harvest and post-harvest brown rot
Benefits of post-harvest fungicidal treatments:
inhibit sporulation of existing infections
prevent new infections (wound infections)
is a contact or wound protection treatment?