effect of the interaction of variety resistance and
TRANSCRIPT
EFFECT OF THE INTERACTION OF VARIETY RESISTANCE AND FUNGICIDE DOSES IN
POTATO LATE BLIGHT CONTROL
Acuña, I, C. Sandoval, F. Cádiz and M. Vargas
Potato crop and late blight in Chile
Integrated Pest Management Vision
Farmer
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Genotype frequency of P. infestans populationon in southern Chile using SSR analysis. Seasons 2003/04 to 2011/12
A1, resistant to Metalaxil
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
2003/04 2004/05 2006/07 2007/08 2008/09 2009/10 2010/11 2011/12
Ge
no
typ
e
fre
qu
en
cy
Genotype 24
Genotype 23
Genotype 22
Genotype 21
Genotype 20
Genotype 19
Genotype 18
Genotype 17
Genotype 16
Genotype 15
Genotype 14
Genotype 13
Genotype 12
Genotype 11
Genotype 10
Genotype 9
Genotype 8
Genotype 7
Genotype 6
Genotype 5
Genotype 4
Genotype 3
Relative Susceptibility to late blight in different commercial potato cultivars in Chile
hi
cde
gh ghi
k
efg
ghi
a
cdc
cd
j
a
ij
fgh gh
cde
ab
def
b
0
10
20
30
40
50
60
70
80
90
100
RA
UD
PC
Yagana
Desiree
Asterix
Rosara
Shepody
Karu
Pukara
Sinfonia
Rom
ano
Patagonia
Granola
Atlantic
Am
adeus
Bintje
Rodeo
Red S
carlett
Mozart
Cornado
Cardinale
Baraka
ANOVA: CV 13.62, p=0.0001, LSD (p=0.05) 10.05. ANOVA: CV 13.62, p=0.0001, LSD (p=0.05) 10.05.
DSS Chile: www.tizon.inia.cl
Weather station network
Main Objective
To develop an Integrated Pest Management strategy to control late blight in the potato crop in southern Chile
Methodology
• Four Experiment:
– Irrigation and schedule application of fungicide
– Irrigation and DSS application of fungicide
– Dryland and schedule application of fungicide
– Dryland and DSS applications of fungicide
• Split splot design and 3 repetitions
• Treatment:
– Fungicide Rate: 0, 50, 75, 100 % of the commercial dose. - Clorotalonil 720 (Bravo 1.5 l/ha). - Propamocarb + Fluopicolide 687.5 (Infinito 2 L/ha).
– Three cultivars: Symfonia (R), Patagonia (MR), Yagana (S).
Results
Late blight DSS: Irrigated and dryland field
Symfonia
Yagana
0
500
1000
1500
2000
2500
3000
3500
4000
0% 50% 75% 100% 0% 50% 75% 100% 0% 50% 75% 100% 0% 50% 75% 100%
Irrigated field DSS (a)Dry land field DSS (b)
Irrigate field SA (a)
Dry land field SA (b)
AU
DP
C
ANOVA ExperimentsProbability = <0,0001
ANOVA DosesProbability = <0,0001LSD = 67,3Rate 0% (a)Rate 50% (b)Rate 75% (c)Rate 100% (d)
c
b
a
ANOVA CultivarProbability = <0,0001LSD = 58,2
Effect of application, fungicide rate, cultivar
Symfonia
Patagonia
Yagana
0
500
1000
1500
2000
2500
3000
3500
0%50%
75%100%
c
a
aa
d
ab
aa
e
b
ab
a
AU
DP
C
Rate of commercial doses (%)
Irrigation and Schedule application
c
b
a
a b bc c
ANOVA: p doses<0.0001, p cultivar< 0.0001, p doses*cultivar< 0.0001
Symfonia
Patagonia
Yagana
0
500
1000
1500
2000
2500
3000
0%50%
75%100%
b
aa
a
c
aa
a
d
ab
aa
AU
DP
C
Rate of commercial doses (%)
Dryland and Schedule application
c
b
a
a b
b b
ANOVA: p doses<0.0001, p cultivar< 0.0001, p doses*cultivar< 0.0001
Symfonia
Patagonia
Yagana
0
500
1000
1500
2000
2500
3000
3500
0%50%
75%100%
AU
DP
C
Rate of commercial doses (%)
Irrigation and DSS application
b
b
a
a b c c
ANOVA: p doses<0.0001, p cultivar< 0.0003, p doses*cultivar< 0.5394
Symfonia
Patagonia
Yagana
0
500
1000
1500
2000
2500
3000
3500
0%50%
75%100%
c
aa
a
c
a
aa
d
b
aa
AU
DP
C
Rate of commercial doses (%)
Dryland and DSS application
c
b
a
a b c
c
ANOVA: p doses<0.0001, p cultivar< 0.0001, p doses*cultivar< 0.0001
Conclusions
• A late blight IPM strategy considers many factors: pathogen, cultivar resistance and environmental conditions
• However, farmers want to know what product to use.
• Then, the information of WHAT, WHEN and HOW MUCH to spray, need to be estimated.
• It was possible to determine significant differences for management, cultivar susceptibility and fungicide rate.
• The interaction rate of fungicide and cultivar susceptibility showed significant differences under most of the conditions evaluated.
• It is possible to reduce the fungicide rate with a more resistant cultivar.
Thank you¡¡¡
Finance by: Agricultural Innovation Agency (FIA) and The Potato Consortium of Chile