Citrus Citrus Black Spot Black Spot and and its

8/27/2010
Citrus Black Spot
First occurrence in São Paulo
1992
Citrus Black Spot and its
management in Brazil
Conchal
Eduardo Feichtenberger
U.P.D.Sorocaba/APTA
[email protected]
Citrus Black Spot
Citrus Black Spot
(Guignardia citricarpa
citricarpa))
Importance
Reduction of fruit value in the fresh fruit market
Host List
Never found in Persian (Tahiti) lime
Citrus spp.:
Lemons
Sweet oranges
Mandarins & Tangerines
Tangelos
Tangors
Hybrids
Resistant Genotypes:
Chinotto mandarin (C.myrtifolia
(C.myrtifolia))
Poncirus trifoliata
Kumquat (Fortunella
(Fortunella spp.)
Severinia buxifolia
(Aguilar--Vildoso et al., 2002)
(Aguilar
Florida: …”CBS causes early fruit drop, reduces crop yield and renders the
highly blemished fruit unmarketable”(USDA,2010).
Citrus Black Spot
Citrus Black Spot
(Guignardia citricarpa
citricarpa))
(Guignardia citricarpa
citricarpa))
Importance
Importance
To restrict exportation of fresh fruits
(mostly to European countries)
Sweet orange fresh fruit market
Reduction fruit value due to CBS: 20 – 30%
CEAGESP, June 2010
1
8/27/2010
Brazilian Citrus Industry
Brazilian Exportation of Citrus Fresh Fruits
Production Destination (%)
Sweet Oranges
Ton
65.9
90,118.7
33.5
50,140.5
0 140
49 48
49,748.7
38,257.2
30,652.1
26,185.2
0.6
Processing
Brazilian Fresh Fruit Market
Fresh Fruit Exportation
2004
2005
2006
2007
Source: Abecitrus, 2006.
Brazilian Exportation of Citrus Fresh Fruits
2009
Year
Brazilian Exportation of Citrus Fresh Fruits
Mandarins
Tahiti Lime
66,374.1
Ton
Ton
2008
Source: SECEX / DATAFRUTA / IBRAF
18,014.1
58,250.1
60,335.4
51,480.7
44,258.2
12,474.8
10,713.1
,
37,326.2
,
6,761.1
6,127.7
4,411.9
2004
2005
2006
2007
2008
2009
Year
Source: SECEX / DATAFRUTA / IBRAF
2004
2005
2006
2007
2008
2009
Year
Source: SECEX / DATAFRUTA / IBRAF
Citrus Black Spot
(Guignardia citricarpa
citricarpa))
Importance
Premature fruit drop reducing yield
2
8/27/2010
Citrus Black Spot Control
Valencia sweet orange – Mogi Guaçu, 2001/02
70
63.7b
FRUIT DROP
60
Citrus Black Spot
Fruit D
Drop (%)
50
40
30
20
17.6a**
Disease Cycle
23.0 a
20 4
20.4a
10
0
Cabendazim
Pyraclostrobin
Trifloxytrobin
Control
Fungicidal Treatments
** 1ª e 2ª sprays at interval of 4 weeks with copper hydroxide (90g metallic Cu/100L) + spray oil (0.25%)
3ª e 4ª sprays at interval of 6 weeks with carbendazin (25g /100L) or estrubilurin (2,5g a.i../100L), in mixture with mancozeb
(160g/100L) + spray oil (0.25%)
** Values followed by same letter do not differ significantly (Duncan, P ≤ 0,05).
Importance of leaves
leaves,, fruits and branches as source of inoculum
Importance of fruits and dead branches
Water splash
ascospores
wind
(40 – 180 days)
Citrus Black Spot Management
Citrus Black Spot Management
Preventive Measures
Regulatory measures
Use of clean propagative materials
Preharvest
Measures
Postharhest
Measures
Control led traffic of people, vehicles and equipments
3
8/27/2010
Exportion of Citrus Fresh Fruits to European
Countries
Regulatory Measures
Interstate trade of fresh fruits with leaves is forbiden in Brazil.
Requirements
1. Registration of Orchards plots
(up to 3 months before harvesting)
2. Registration of Packinghouses
(January 1st. to April 30th.)
3. Field inspection for CBS detection
(State Regulatory Office inspectors)
4. Fruit Sampling for Lab Test to accelerate fruit symptom development
(Sampling date must be informed to the State Regulatory Office at least 7
days in advance)
Sampling fruits for the Lab Test to accelerate
CBS symptom development.
development.
Citrus Black Spot
( Guignardia citricarpa )
Test to accelerate fruit symptom development
• at least 30 days before harvesting;
• in declining trees;
•
Deep fruits in ethephon solution (750 ppm) for 5 minutes;
• in the lower canopy;
• in the face of the tree most exposed to sun light;
• mature fruits or fruits that have reached final size;
• in 1% of the trees (samples most have at least 20 fruits)
Citrus Black Spot
( Guignardia citricarpa )
Test to accelerate fruit symptoms development
•
Deep fruits in ethephon solution (750 ppm) for 5 minutes
•
Incubation of fruits at temperatures ≥ 25°C, under continuous light, during 28
days;
•
Microscopic and visual observations of fruits for CBS symptoms;
4
8/27/2010
Citrus Black Spot
Citrus Black Spot
(Guignardia citricarpa)
( Guignardia citricarpa )
Symptoms in Fruits Treated with Ethephon
Test to accelerate fruit symptoms development
•
Deep fruits in ethephon solution (750 ppm) for 5 minutes;
•
Incubation treated fruits at temperatures ≥ 25°C, under continuous light,
during 28 days;
•
Microscopic and visual observations of fruits for CBS symptoms;
•
Diagnosis confirmation by isolating Guignardia citricarpa;
48 hours
Freckle spot
Virulent spot
Exportion of Citrus Fresh Fruits to European
Countries
Requirements
Exportion of Citrus Fresh Fruits to European
Countries
Requirements
5. Preharvest field inspection for CBS detection
(State Regulatory Office inspectors)
Citrus Black Spot
Preventive Measures
6. Packinghouse inspection during processing and packing
(Regulatory Federal Office inspectors) i
Production of nursery trees free of
G.citricarpa
• Healthy nursery trees:
Optimal conditions for infection:
temperature: 21 – 32ºC
wetting period: 24- 48h
5
8/27/2010
Production of nursery trees free of
G.citricarpa
Citrus Black Spot
Traffic Control During Harvest
Preventive Measures
• Healthy nursery trees
trees::
• Controlled traffic of
vehicles
Citrus Black Spot Management
Citrus Black Spot Management
Cultural Practices
Removal of fallen leaves from the orchard floor
Cutural Practices
6
8/27/2010
Citrus Black Spot Management
Citrus Black Spot Management
Cultural Practices
Cultural Practices
Use of mulching over leaf litter;
Citrus Black Spot
Horticultural Practices for Citrus Health
• Weed Control
Citrus Black Spot Management
Forage interplanting for mulching production
Citrus Black Spot Management
Forage interplanting for mulching production
Herbicides in
total area
Natural Vegetation
Source: F.A. Azevedo
Interplanting with Coastcross grass (Cynodon dactylon cv. coastcross) or Peanut
(Arachys pintoi)
Source: Bellotte,J.A.M. 2006
Forage Turnip
Raphanus sativus
White Lupine
Lipinus albus
Black Oat
Avena strigosa
7
8/27/2010
Citrus Black Spot Management
Citrus Black Spot Management
Forage interplanting for mulching production
Comparison of Mowing Machines
Cultural Practices
Pruning and removal of dead branches;
“Ecological” Mowing Machine
Conventional Mowing Machine
X
Source: F.A. Azevedo
Reduction of disease
severity by 23% to 46%
Conventional
Ecological
Source: F.A. Azevedo
Source: F.A. Azevedo
Cultural practices to minimize CBS severity
Citrus Black Spot Management
‘Murcott
Murcott’’ Tangor.
Tangor. Casa Branca, 2004/05
Pruning and removal of dead branches
Cultural Practices
Irrigation management
Without pruning
With pruning
NOZAKI(2007) – Positive correlation between dead branches and CBS severity (false melanose type symptom).
Citrus Black Spot
Horticultural Practices for Citrus Health
• IRRIGATION
• to provide uniform and regular blossoming
blossoming;;
• to reduce water stress
• to reduce leaf fall during autumn and winter
Pseudothecium production favored by alternating
leaf wetting and leaf dryness.
8
8/27/2010
Citrus Black Spot
Irrigation to reduce leaf fall during dry season
Irrigation Methods
Number of dead leaves with pseudothecia in the orchard floor
Number of Dead leaves with pseudothecia**
Year*
Microsprinkles
Drip Irrigation
1995
20 8
20.8
2 75
2.75
Flood Irrigation
0 50
0.50
1996
16.5
0
1.00
1997
13.0
0.25
2.75
* In October of each year
**Number of pseudothecia of Guignardia citricarpa in the orchard floor (0.25 m²), bellow the canopy of the trees.
Source: Alcoba et al,1999.
Citrus Black Spot Management
Citrus Black Spot Management
Earlier harvesting
Cultural Practices
Earlier harvesting.
Citrus Black Spot
Chemical management
Citrus Black Spot
Chemical Management
COPPER FUNGICIDES
• Copper sulphate
RATE (g metallic Cu/100
Cu/100L)
L)
90 - 100
• Copper hydroxide
90
• Cuprous oxide
75
• Copper oxychloride
90
9
8/27/2010
Citrus Black Spot
Citrus Black Spot
Chemical Management
Chemical Management
Dithio--carbamates
Dithio
Dithio-carbamates
Rate (g a.i./100L)
Mancozeb
(g a.i./100
100L)
L)
25
• Carbendazin
25
• Thiophanate
Thiophanate--methyl
37.
37.5
70
Citrus Black Spot
Citrus Black Spot
Chemical Management
Chemical control
STROBILURINS
FUNGICIDES
RATE
• Benomyl
110 – 160
Propineb
BENZIMIDAZOLES
28 days
Rates
(g a. i. / L)
Copper
Trade compound (g ou mL/ 2,000L)
Azoxystrobin
4–8
Pyraclostrobin
3.75
300mL
(200-300mL)*
Trifloxystrobin
3.75
150g
(200g)*
160 – 320g
28 days
Copper
42 days
Benzimidazole
or estrobilurine
Benzimidazole
or estrobilurine
(320g)*
(*) Rates recommended by the Citrus Integrated Production Committee.
Petal fall
Fruit Susceptibility (5 -6 months)
CITRUS BLACK SPOT CONTROL
Fungicide Sprays at Low and High Volume
Field Trials
►Rio Claro, 2003/04
►Rio Claro, 2004/05
►Mogi Guaçu: 2007/08 e 2008/09
10