Colloque sur la pomme de terre Une production à protéger
13 novembre 2009, Québec
Utilisation des produits à base d’acide phosphoreux pour lutter contre le mildiou et la pourriture rose
Rick D. Peters, Ph.D., chercheur scientifique, AAC, Charlottetown Île-du-Prince-Édouard
Note : Cette conférence a été présentée en anglais lors de l’évènement et la
présentation PowerPoint a été publiée dans le cahier du participant.
Pour commander le cahier du participant, consultez le catalogue des publications du CRAAQ
1
UtilisationUtilisation des des produitsproduits à base d’ à base d’ acideacide phosphoreuxphosphoreux pour pour lutterluttercontrecontre le le mildioumildiou et la et la pourriturepourriture rose rose
Use of phosphorous acidUse of phosphorous acid--based products for control of late blight based products for control of late blight and pink rot of potatoesand pink rot of potatoes
Rick D. PetersAgriculture and Agri-Food Canada, Charlottetown
Pink Rot and Late BlightPhytophthora erythroseptica and P. infestans
Pink rot Late blight
2
Sensitivity to Ridomil Gold (metalaxyl-M)0 1 10 100
MHR
MMR
MS
Sensitivity of P. erythroseptica to metalaxyl-M2005 Canadian Survey
2.0
EC
(pp
m)
1.5
1.0
0.5
50
FieldPEINew BrunswickManitobaAlberta
121113109874365210.0
7 resistant isolates (14%) out of 49 isolates collected in total
2007: 2 isolates from Quebec = sensitive1 isolate from NB = resistant
3
Late Blight (Phytophthora infestans)2006 and 2007 Canadian Surveys
2006 2007MS MMR MHR MS MMR MHR
10% 65% 25% 16% 52% 32%
P d i tl A2 US 8 t• Predominantly A2, US-8 genotype• Some exceptions (A1, US-11 genotype)
Late Blight (Phytophthora infestans)2009 Canadian Survey
O l f Q b• One sample from Quebec• Preliminary result = A2, US-8• Other isolates from NB, PE also A2, US-8
4
Phosphorous acid-based products
• Mono- and dibasic sodium, potassium and ammonium salts of phosporous acid
• Neutral blend of phosphorous acid salts; converted tophosphite ions in the plant
• Systemic• Low environmental risk• Mode of action direct toxicity and/or stimulation of
plant defences(G f W P ki S h Li NSAC)(Gefu Wang-Pruski, Sanghyun Lim – NSAC)
• Confine, Phostrol, Rampart, etc.
• slide courtesy of Dr. Jeff Miller, Idaho
5
Suppression of pink rot and late blightby phosphorous acid (Confine)
Post-harvest Application100
405060708090
100
LBPR-RES
%tuber rot
010203040
C P T.5X TX T2X CX C.5XT CT C2XT
PR-SEN
Field Trials – 2007-2009Cavendish Farms
*with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
Cultivars: ShepodyRusset Burbank
Replications: 4 (RCBD)
Treatments: Check (water)Confine (5.8L product/250L water/ha)Bravo (2L product/250L water/ha)Confine + Bravo
Applications: 10
6
Phosphorous acid for control of foliar late blight - 2007* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
Phosphorous acid for control of foliar late blight – 2008 and 2009 * with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
• Foliar disease ratings based on natural disease progressionin the fieldin the field
7
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2008 Fungicide Trial - Shepody
Check Bravo PA PA+Bravo (100%)
40
60
80
100
Dis
ease
d Fo
liage
0
20
40
Aug 20 Aug 25 Aug 30 Sep 4 Sep 9 Sep 14 Sep 19 Sep 24
Sampling Date
% D
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2009 Late Blight Ratings - Shepody
100
Check Confine Bravo Confine + Bravo
40
50
60
70
80
90
% D
efol
iatio
n
0
10
20
30
40
28-Jul 4-Aug 11-Aug 18-Aug 25-Aug 1-Sep 8-Sep 15-Sep
%
8
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2008 Fungicide Trial - Russet Burbank
Check Bravo PA PA+Bravo (100%)
40
60
80
100
isea
sed
Folia
ge
0
20
40
Aug 20 Aug 25 Aug 30 Sep 4 Sep 9 Sep 14 Sep 19 Sep 24
Sampling Date
% D
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2009 Late Blight Ratings - Russet Burbank
100
Check Confine Bravo Confine + Bravo
50
60
70
80
90
100
Def
olia
tion
0
10
20
30
40
28-Jul 4-Aug 11-Aug 18-Aug 25-Aug 1-Sep 8-Sep 15-Sep
% D
9
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
• Tubers were harvested to assess overall yield andtuber rot
Suppression of late blight tuber rotby phosphorous acid (Confine) and Bravo
Results at Harvest - 2008
70
30
40
50
60
70
Shepody
Russet Burbank
%tuber rot
0
10
20
30
Check PA Bravo PA + Bravo
Russet Burbank
10
Crop YieldResults at Harvest - 2008
50
20253035404550
Shepody
Russet Burbank
HealthyYield/plot
(kg)
05
101520
Check PA Bravo PA + Bravo
Russet Burbank
Suppression of late blight tuber rotby phosphorous acid (Confine) and Bravo
Results at Harvest - 2009
25
10
15
20
25
Shepody
Russet Burbank
%tuber rot
0
5
10
Check PA Bravo PA + Bravo
Russet Burbank
11
Crop Yield - TotalResults at Harvest - 2009
60
30
40
50
60
Shepody
Russet Burbank
HealthyYield/plot
(kg)
0
10
20
Check PA Bravo PA + Bravo
Russet Burbank
Suppression of late blight tuber rotby phosphorous acid (Confine) + Bravo
Results after inoculation of healthy tubers from field plots
40
60
80
%tuber rot
aa
b
b
a a
0
20
Check PA Bravo PA + Bravo
Shepody Russet Burbank
b b
12
Suppression of pink rotby phosphorous acid (Confine) + Bravo
Results after inoculation of healthy tubers from field plots
40
60
80
100
%tuber rot
a
b
c
a
a
0
20
Check PA Bravo PA + Bravo
Shepody Russet Burbank
cb b
Photos: Guardian file, MacPhail Woods, Rob LeClair/CBC, PEI Government
13
Cultivar: Russet Burbank
Replications: 4 (RCBD)
Field Trials – 2008 and 2009Cavendish Farms
p ( )
Treatments: Check (water)Confine (5.8L product/250L water/ha)Bravo (2L product/250L water/ha)Confine + Bravo (tank-mix)Confine + Bravo (alternating)C fi + B (1 5L d t/h )Confine + Bravo (1.5L product/ha)Confine + Bravo (1.0L product/ha)Confine + Bravo (0.5L product/ha)Confine + Bravo (0.2L product/ha)
Applications: 10
120CH
Impact of foliar treatment on the progression of late blight in a field trial conducted in 2008
20
40
60
80
100 BRCONCBRTCBRACBR75CBR50
Disease severity
(%)
0
20
A20 A27 S02 S11 S25
CBR25CBR10
Date (2008)
14
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2009 Late Blight Ratings - Russet BurbankConfine Treatments
Check Bravo Confine + Bravo 1.5L
50
60
70
80
90
100
liatio
n
Confine + Bravo 2L Confine + Bravo 1L Confine + Bravo 0.5LConfine + Bravo 0.2L Confine L Confine, Bravo
0
10
20
30
40
50
28-Jul 4-Aug 11-Aug 18-Aug 25-Aug 1-Sep 8-Sep 15-Sep
% D
efo
Phosphorous acid and Bravo for control of foliar late blight* with R. Coffin, Cavendish Farms and G. Wang-Pruski, NSAC
2009 Late Blight Ratings - ShepodyConfine Treatments
Check Bravo Confine + Bravo 1.5L
50
60
70
80
90
100
liatio
n
Confine + Bravo 2L Confine + Bravo 1L Confine + Bravo 0.5LConfine + Bravo 0.2L Confine L Confine, Bravo
0
10
20
30
40
50
28-Jul 4-Aug 11-Aug 18-Aug 25-Aug 1-Sep 8-Sep 15-Sep
% D
efo
15
Suppression of late blight tuber rotby phosphorous acid (Confine)/Bravo
Results at Harvest – 2008 Russet Burbank
4550
202530354045
%tuber rot
05
1015
CH CON BR CBR CBR CBR CBR CBR CBR5.8 2.0 2.0 2.0 1.5 1.0 0.5 0.2
Suppression of late blight tuber rotby phosphorous acid (Confine)/Bravo
Results at Harvest – 2009 Russet Burbank
4 55
22.5
33.5
44.5
%tuber rot
00.5
11.5
CH CON BR CBR CBR CBR CBR CBR CBR5.8 2.0 2.0 2.0 1.5 1.0 0.5 0.2
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• Use good cultural practices (reduce wounding, avoid harvesting wet spots etc )
P. erythroseptica - DISEASE MANAGEMENT
harvesting wet spots, etc.)• In-furrow application of Ridomil Gold provides excellent
suppression of pink rot where sensitive strains of the pathogen occur
• Strains of the pink rot pathogen resistant to metalaxyl-m are starting to appear in NB (late blight pathogen already insensitive)Rid il G ld i bl t t l i k t i th• Ridomil Gold is able to control pink rot in the presence of late blight
• Products containing salts of phosphorous acid provide excellent control of pink rot when applied foliarly (minimum of 3 applications at recommended rate) and as a post-harvest treatment
P. infestans - DISEASE MANAGEMENT• Remove culls and volunteers• Use clean seed• Fungicide seed treatment to prevent spread
during cutting and handlingg g g• Application of protectant and locally systemic
fungicides during the growing season• Forecasting systems• Products containing salts of phosphorous acid
provide control of foliar late blight and tuber rot when applied foliarly (minimum of 3 applicationsat recommended rate) and as a post-harvest treatment
• Best approach (for yield and disease control) is to incorporate PA into a protectant spray program, which also allows reduction in rates of protectant products
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Advantages of a phosphorous acid + protectant foliar program:• Excellent control of foliar late blight• Combines the benefits of a protectant with a systemic productCombines the benefits of a protectant with a systemic product• Superb control of late blight tuber rot, even if foliar disease
is present (especially late in the season)• Allows usage of reduced rates of protectants for
environmental benefits• Excellent control of pink rot and provides a resistance
management tool for Ridomilg• Suppression of late blight and pink rot in tubers lasts into
storage• Suppression of early blight• Post-harvest application of PA for late blight, pink rot
and silver scurf
Acknowledgments
FundingFunding
Agriculture and Agriculture and AgriAgri--Food CanadaFood CanadaCavendish FarmsCavendish FarmsPest Management Centre Pest Management Centre –– OttawaOttawa
MUR06MUR06--150150Agronomy Company of CanadaAgronomy Company of Canada
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Acknowledgments
AAFC CharlottetownAAFC Charlottetown
Bud PlattBud Platt
Cavendish FarmsCavendish Farms
Robert CoffinRobert CoffinBud PlattBud PlattRick PetersRick Peters
Ian MacdonaldIan MacdonaldKathy DrakeKathy DrakeRoger HenryRoger Henry
Harrington Farm StaffHarrington Farm Staff
Robert CoffinRobert CoffinStephanie Stephanie VeenhuisVeenhuis--MacNeilMacNeilWilliam HardyWilliam Hardy
Nova Scotia Agricultural CollegeNova Scotia Agricultural College
GefuGefu WangWang--PruskiPruskiSanghyunSanghyun LimLimg yg y
Participating Potato GrowersParticipating Potato Growers
Provincial Government RepsProvincial Government Reps& Diagnostic Clinics& Diagnostic Clinics
Industry RepsIndustry Reps
Thank you !Thank you !yyFor more information:
–Contact Rick Peters: [email protected] –Web site: www.agr.gc.ca/science/charlottetown
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