Contenu connexe
Plus de Avocados Australia
Plus de Avocados Australia (20)
Elizabeth Dann
- 1. Impacts of fruit disease management
on quality
Liz Dann, Lindy Coates,
Luke Smith, Ken Pegg,
Jan Dean, Tony Cooke
QPIF, Indooroopilly, QLD
- 2. Queensland Primary Industries and Fisheries
Topics covered
• Overview of anthracnose and stem-end rot
• Experimental results
• Rootstocks, including nutrition
• Crop load, including nutrition
• Integrated control
• Field fungicides, including strobilurin group
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 3. Queensland Primary Industries and Fisheries
Postharvest diseases
stem-end rot
anthracnose
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 4. Queensland Primary Industries and Fisheries
Anthracnose (Colletotrichum gloeosporioides)
Infection Symptoms
occurs in field develop
dormant
from fruit set to during fruit
harvest ripening
period
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 5. Queensland Primary Industries and Fisheries
Stem-end rot (many fungi)
• Botryosphaeria spp
• Lasiodiplodia theobromae
• Colletotrichum gloeosporioides
• Phomopsis perseae
• Thyronectria pseudotrichia
Stem-end rot (SER) fungi colonise the
stem tissue of avocado trees without
causing disease
Symptoms develop during fruit ripening
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 6. Queensland Primary Industries and Fisheries
Effect of rootstock on fruit quality & major nutrients
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 7. Queensland Primary Industries and Fisheries
Rootstock affects postharvest disease
• Fruit harvested from T. Whiley’s rootstock trials at
– Childers, QLD (‘Hass’ in 2008 and 2009)
– Walkamin, QLD (‘Shepard’ in 2009)
– Pemberton, WA (‘Hass’ in 2008)
– Hampton, QLD (‘Hass’ in 2007 and 2008)
• Ripened at 23° & 65% RH (Indooroopilly)
C
• Stored 5 weeks at 5.5° then ripened 20° (Maroochy)
C, C
• Assessed for postharvest disease
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 8. Queensland Primary Industries and Fisheries
Effect of rootstock on anthracnose, Hampton 2008
40
% anthracnose a
30 ab
20 bc
c
c c
10
0
3
s
k
d
no
7
-0
as
ic
ee
e
ta
lv
SR
uk
H
R
Zu
Ve
D
SH
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 9. Queensland Primary Industries and Fisheries
Effect of rootstock on fruit skin N:Ca ratio, Hampton 2008
50
Skin N:Ca
40
30
20
10
0
Velvick Reed SHSR- Zutano Duke 7 Hass
03 © The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 10. Queensland Primary Industries and Fisheries
Effect of rootstock on leaf N:Ca ratio, Hampton 2009
4
Leaf N:Ca
a
ab ab
3 abc
bcd
cd
d
2
1
0
Velvick SHSR- A10 Reed Duke 7 Zutano Hass
03 © The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 11. Queensland Primary Industries and Fisheries
Correlations between disease, yield & nutrient balance –
Hampton 2008
Variable 1 Variable 2 P r (correlation Relationship
coefficient)
Anthracnose Yield per tree 0.044 0.30 -
severity
Anthracnose Fruit skin N:Ca 0.011 0.39 +
severity
Stem-end rot Fruit skin N:Ca 0.013 0.38 +
severity
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 12. Queensland Primary Industries and Fisheries
Effect of rootstock on anthracnose, Pemberton 2008
20 % anthracnose
a
ab
bc
cd
d
d
0
A10 Reed Velvick Duke 7 Zutano Barr
Duke
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 13. Queensland Primary Industries and Fisheries
Effect of rootstock on fruit skin N:Ca ratio, Pemberton 2008
20
N:Ca
a
a
ab
ab
bc
c
0
Velvick A10 Zutano Duke 7 Barr Reed
Duke
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 14. Queensland Primary Industries and Fisheries
Effect of rootstock on anthracnose, Childers 2009
80 % anthracnose a
ab
abc
abcd abcd
60 bcd
cd cd
d d cd
40
20
0
al
3
2
3
al
o
SH 10
S- k
10
e7
k
-0
-0
-0
an
c
S- lvic
ab
ab
A
-A
vi
uk
SR
SR
SR
ut
S-
N
el
-N
C
Ve
-D
-Z
SH
-V
H
C
C
S-
-S
C
C
S-
C
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 15. Queensland Primary Industries and Fisheries
Effect of rootstock on N:Ca ratio, Childers 2009
60
N:Ca
a
40
b
bc bc
bc bc bc bc
bc bc
c
20
0 al
3
2
-D 3
SH al
o
10
10
ck
7
k
-0
-0
-0
an
ic
ab
ab
e
A
-A
vi
SR
SR
SR
lv
uk
ut
S-
N
el
-N
C
Ve
S-
-Z
SH
-V
H
C
S-
-S
C
C
C
S-
S-
C
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 16. Queensland Primary Industries and Fisheries
Significant trends
• Rootstock affects fruit quality
– All locations
• yield ↓ as anthracnose severity ↑
– Childers and Hampton 2008
• anthracnose severity ↑ as N and/or N:Ca ↑
– All locations
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 17. Queensland Primary Industries and Fisheries
Effect of crop load on fruit quality
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 18. Queensland Primary Industries and Fisheries
Effect of crop load on anthracnose disease
100 A
% severity
% incidence B
80
N:Ca
60 a
40 y
b
z
20
0
high load low load high load low load
2007 2008
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 19. Queensland Primary Industries and Fisheries
Effect of crop load on stem-end rot disease
40
% severity
% incidence
20
a
b
0
high load low load high load low load
2007 2008
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 20. Queensland Primary Industries and Fisheries
Crop load affects quality
• ↓ anthracnose & ↓ N:Ca with ↑ crop load
• But, ↑ stem-end rot with ↑ crop load
– Stem-end rot more severe when trees are stressed
– Optimum irrigation and nutrition critical for control
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 21. Queensland Primary Industries and Fisheries
Using fungicides to improve fruit quality
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 22. Queensland Primary Industries and Fisheries
Assessment of new strobilurin products
• Initially a product screening trial (2008)
– pyraclostrobin – Group 11 (previously Group K)
– metiram – zinc based protectant fungicide
– boscalid – locally systemic f’cide with wide activity
– pyraclostrobin + boscalid
– pyraclostrobin + metiram
• Then as part of an anti-resistance program (2009)
– Pyraclostrobin ± metiram
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 23. Queensland Primary Industries and Fisheries
Product screening trial, Duranbah 2008 (cv. Reed)
% severity anthracnose % incidence anthracnose
60 a
50
ab
40
abc
abc
30
bc
20
c
10
0
untreated p'strobin boscalid p'strobin + p'strobin + Amistar
boscalid metiram
p’strobin = pyraclostrobin
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 24. Queensland Primary Industries and Fisheries
Anti-resistance trial, Glasshouse Mtns 2009 (cv. Hass)
% severity anthracnose % incidence anthracnose
120
100
a
80
ab
60 bc
bc bc
c
40 c
20
0
untreated copper Amistar + p'strob 20 p'strobin p'strobin p'strobin
copper + copper 20 + 40 + 40 +
metiram + copper metiram +
copper copper
p’strobin = pyraclostrobin
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 25. Queensland Primary Industries and Fisheries
Most effective and responsible use of fungicides
• Always follow label directions
• Protectants – no “short-cuts” in copper spray program
(every 28 days in fine weather, every 14 days if wet)
• Strobilurins – only Amistar® registered in avocado
– post-infection activity
– use with copper sprays in an anti-resistance strategy
– effective when applied close to harvest and after
extended periods of wet weather
• Postharvest – apply prochloraz within 24h after harvest
– use in conjunction with field spray program
– can’t be used on fruit destined for Europe
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 26. Queensland Primary Industries and Fisheries
Integrated control – the complete picture
Tree Strategic Careful Postharvest
husbandry fungicides harvest care
- nutrition (N, Ca) - protectants and - maturity %DM - cool chain
- canopy mgt post-infection - wet weather - pre-condition
- mulching - phosphorus acid - CA, ethylene
- root health - postharvest
- irrigation © The State of Queensland, Department of Employment, Economic Development and Innovation, 2009
- 27. Queensland Primary Industries and Fisheries
Acknowledgements
Thank you to the many growers
and collaborators for supporting
our research!
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009