infinito tuberblight control through reduction of sporangia …infinito 1,6 l/ha shirlan acrobat...
TRANSCRIPT
Dr. Latorse, M.P, Jarry F., Mercier V., Veloso S.
Bologna Potato Workshop May 2-5 2007
Tuber blight control: effect of foliar applied fungicides such as Infinito on viability of sporangia of Phytophthora infestans
Bayer CropScience Research – Bologna Euroblight Slide 2
How to Control Tuber Blight ?
1) Reduction of sporulation
2) Spores + product are washedoff together:direct sporicide effect
3) Newly formed sporangia are affected in their viability :inoculum less infectious
Bayer CropScience Research – Bologna Euroblight Slide 3
In vitro sporangia germination test in aquaeousmedia
On planta sporangia infectivity test on foliar discs or tuber slices
Sporangia viability (vital staining)
Methods for Viability Evaluation
A rapid Live/dead viability test using fluorescent fluorochromes developed / validated
Bayer CropScience Research – Bologna Euroblight Slide 4
Live/ dead Viability Test Comparison
FDA fluoresces bright green in viable spores / PI fluoresces red-orange in non viable spores under blue light
Advantage / disavantage using FDA alone or in mixture Kit (FDA/PI)
- Live /dead viability Kit formulation stable for observation all day long // FDA alone
- PI is a potential mutagen: handle with appropriate caution
No significant differences detected between FDA alone and Kit (FDA+PI)Ratio Alive/dead sporangia depends on time of sporangia harvest in relation to beginning of sporulation and also links to the ability of products to reduce sporulation
Bayer CropScience Research – Bologna Euroblight Slide 5
Translaminar Activity (% infestation)
Strong translaminar activity of Infinito
Good translaminar effect of fluopicolide and dimethomorph with kinetic response
Rapid penetration of fenamidone
Quick penetration cymoxanil but short persistance due to quick metabolism
0
20
40
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80
100
3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48
UTC
Infinito 1,2 L/ha
Infinito 1,4 L/ha
Infinito 1,6 L/ha
Shirlan 0,4 L/ha
Acrobat M 2 kg/ha
Fluopicolide 0.18 L eq 1,4 L/haInfinitoFluopicolide 0.2 L eq 1,6L/haInfinitoCurzate M 2kg/ha
Fenamidone 0.3 L eq 1,5kg/haSereno
% infestation
Time between treatment and inoculation
Bayer CropScience Research – Bologna Euroblight Slide 6
Translaminar Activity (% infestation)
Translaminar effect of fungicides with 24 h interval between preventive treatment and inoculation
0
20
40
60
80
100
UTC Fluopicolide0,16 L/ha (eq1.2 Infinito)
Fluopicolide0,18 L/ha (eq1.4 Infinito)
Fluopicolide 0,2L/ha (eq 1.6
Infinito)
Infinito 1,6 L/ha Shirlan Acrobat Fenamidone0,3 L/ha (eq 1.5Kg/ha Sereno)
% in
fest
atio
n
Fluopicolide translaminar activity with clear dose responseInfinito strong translaminar profile within 24 hours after treatment Sporangia for secondary infection could not be harvested for Infinito
Bayer CropScience Research – Bologna Euroblight Slide 7
Sporangia Viability by Vital Staining
Dead sporangia (%) by viable staining 7 days after inoculation ( 48h, preventative)
Contact fungicides do not influence the viability of newly formed sporangiaTranslaminar product such as fenamidone reduces viability of newlyformed sporangia
0
20
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Control Control 0.4 l/ha 2 kg/ha 1.5 kg/ha
Dead Alive fluazinam mancozeb Sereno
Bayer CropScience Research – Bologna Euroblight Slide 8
Sporangia Viability by Vital Staining
Reduction of viability by translaminar fungicides at curative applicationlower compared to preventativeInfinito provided significant reduction of spore viability
Dead sporangia (%) by viable staining 7 days after inoculation ( 48h, curative)
0
20
40
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80
100
Control Control 0.4 l/ha 1.5 kg/ha 1.6 l/ha 1.6 l/ha
Dead Alive fluazinam Sereno fluopicolide Infinito
Bayer CropScience Research – Bologna Euroblight Slide 9
Anti-sporulant Activity :
Infinito has strong anti-sporulant properties
Sporulation index relative to untreated after curative application
Index (%)
0
20
40
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Control 1.2 l/ha 1.6 l/ha 2.0 l/ha 0,4 l/ha 2.14 kg/ha
Control Infinito Infinito Tattoo C fluazinam mancozeb
Bayer CropScience Research – Bologna Euroblight Slide 10
Infectivity Test (sporangia production)
Infinito reduces the infectivity of newly formed sporangia, coming fromthe reduction of sporangia both number and viability
Infectivity newly formed sporangia (spores / ml)
0
10000
20000
30000
Control 1.2 l/ha 1.6 l/ha 2.0 l/ha 2.14 kg/ha
0
20
40
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100
Control 1.2 l/ha 1.6 l/ha 2.0 l/ha 0,4 l/ha 2.14 kg/ha
Anti-sporulant effect
Control Infinito Infinito Tattoo C mancozeb
Infinito Infinito
Bayer CropScience Research – Bologna Euroblight Slide 11
How to Control Tuber blight
Sporicide effect
Spore viability
Tuber blight control of Infinito based on multiple action
Spore quantity
Bayer CropScience Research – Bologna Euroblight Slide 12
Tuber Blight Control NL
Relative tuber blight infection (%)
0
20
40
60
80
100
0.3 l/ha 0,4 l/ha 0.2 l/ha 1.2 l/ha 1.4 l/ha 1.6 l/ha
(relative % diseased tubers, average of 2 trials BCS Netherlands 2006)
InfinitoFluazinam InfinitoCyazofamidFluazinam Infinito
Bayer CropScience Research – Bologna Euroblight Slide 13
Conclusions / Recommendations
The live/dead viability kit ( FDA & PI) validated as a rapid indicator ofPhytophthora sporangia viabilityTranslaminar fungicides have potential to reduce sporulation according to their kinetics of penetration, bio availability and fungicidal properties
Infinito was confirmed as a strong translaminar and anti-sporulant fungicideInfinito has a multiple action:
– strong sporicide effect– reduction of sporulation– reduction of viability and infection success of sporangia
The properties of fungicides on apparent infection rates should be consideredfor incorporation into DSS to optimise late blight / tuber blight control
Thank you very much for your kind attention