asko hannukkala and ari lehtinen mtt – agrifood research ...€¦ · © mtt, field crop...

© MTT, Field crop protection and agroecology Euroblight, Bologna 03.05.2007

Estimated yield losses caused by potato late blight in Finnish fungicide trials in 1992-2006

Asko Hannukkala and Ari LehtinenMTT – Agrifood Research FinlandAnne Rahkonen, Potato Research Institute


Yield losses caused by Potato Late Blight

Background

•Early outbreaks•In 2000s one month earlier than in 1980s (Hannukkala et al 2007 Plant Pathology 56:167-176)

Three earliest blight observations 1983-2005

-40

-20

0

20

40

60

80

1982 1987 1992 1997 2002

No of days from 1st of July



Background

•Increased use of fungicidesThe average number of applications

0

1

2

3

4

1982 1987 1992 1997 2002



Objective

•Early epidemics – more severe yield losses?•Tuber blight?•Do fungicide programs give more benefit?•Efficacy of mancozeb in comparison to new contact, translaminar and metalaxyl programs



Materials

•Data from fungicide efficacy trials 1992-2006•Two locations (Jokioinen and Lammi)•44 trials with 4 replicates

Treatments:•Untreated control•Mancozeb•New contact (Shirlan, Ranman, Electis)•Translaminar: 2 x (Tattoo, Acrobat, Tanos, Sereno) + 3-5 contact•1-2 metalaxyl + 3-5 contact

0

1

2

3

4

5

6

7

8

1990 1995 2000 2005 2010

MancozebMetalaxyl +New ContactTranslaminar +Untreated

Number of treatments



Results: Leaf blight

0

20

40

60

80

100

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008

Untreated

Fungicideprogram

Leaf blight %, final rating



Results: Leaf blight

0

20

40

60

80

100

1990 1995 2000 2005 2010


Leaf blight %, final rating



Results: Tuber blight

0

5

10

15

20

25

1990 1995 2000 2005 2010

UntreatedFungicide program

Tuber blight




0

5

10

15

20

25

30

1990 1995 2000 2005 2010

MancozebNew Contact

Tuber blight %




0

5

10

15

20

25

30

1990 1995 2000 2005 2010


Tuber blight



Results: healthy marketable yield

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008

Untreated

Fungicide programs

Lin. (Fungicide programs)

Yield increase kg



Results: healthy marketable yield

-5000

0

5000

10000

15000

20000

25000

30000

1990 1995 2000 2005 2010


Yield increase kg



Conclusions

•Risk of yield losses has increased due to earlier epidemics•Fungicide programs give relative good protection•More sprays => higher yield increases•Fungicide programs do not always protect from tuber blight•Untreated plots are sometimes destroyed by leaf blight within few days => less tuber blight than in treated

asko hannukkala and ari lehtinen mtt – agrifood research ...€¦ · © mtt, field crop...

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