IPM in wheat
The EU requires IPM by 2014 what does this mean???
1. Blind Chemical control
–
Schematic and routine treatments
2. Chemical control based on advice
–
Recommendation given by region often using broad spectrum
pesticides
3. Specific control
–
Use economic threshold levels. differentiate between pesticides
(including impact on beneficials)
4. Integrated plant protection
–
Use mainly cultural methods and only limited input of pesticides
5. Integrated agricultural production
–
Use and exploit all positive factors in the agro-ecosystem
Definition given by IOBC
• Two case studies:
– fungicides in cereals
– herbicides in cereals
Elements in wheat IPM
• National monitoring of diseases
• Data on variety susceptibility
• Data on fungicide efficacy. Need for
lots of field trials which support the
use of reduced rates
• Implematation of threshold models
Monitoring network
Need for treatment
No need (45 loc.)
Susceptible variety
Resistant variety
Major thresholds in wheat
Disease
Examples of threshold in CPO
Eyespot
>35% plants attacked at GS 30-32
Mildew
>10% plants attacked from GS 29 (S)
>25% plants attacked from GS 29 (R)
No treatments after GS 40
Septoria
4 days with precipitation from GS 32 (S)
5 days with precipitation from GS 37 (R)
Or attack on third leaf from GS 45-60
Brown rust
Yellow rust
>25% plants attacked (S)
GS 29-60 > 1% plants attacked (S)
Appropriate and reduced dosages
of fungicides
Dt/ha grain per ha
12
10
8
Gross yield
6
4
Net yield
2
0
0
0.2
0.4
0.6
TFI –dose /ha
Control of Septoria in wheat -different input
6 trials from DK
0.8
Optimal dose depends on cultivar
and grain price
Resistant cultivar
14
D 20 €
CD 20 €
D 10 €
CD 10 €
12
10
Net yield gain (dt ha-1)
Net yield gain (dt ha-1)
14
Susceptible cultivar
8
6
4
2
12
10
8
BCD 20 €
CD 20 €
C 20 €
CD 10 €
C 10 €
BCD 10 €
6
4
2
0
0
0,0
0,2
0,4
0,6
0,8
1,0
0,0
Total fungicide input (TFI)
A: GS 25-31. B: GS 32-36. C: GS 37-50. D: GS 51-64
0,2
0,4
0,6
0,8
Total fungicide input (TFI)
1,0
Development of fungicide use in
winter wheat
TFI/Relative dose
2
1,6
1,2
TFI
Dose
0,8
0,4
0
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 '00 '01 '02 '03 '04
Source: Farmstat/Kleffmann/Pesticide statistics
Summary of 73 Danish field trials
on ear treatment in winter wheat
15.0
Net loss compared
with optimum. dt/ha
15
9.8
10
8.4
5.9
5.3
5
2.1
1.1
0.7
0
0.125
0.25
0.375
0.5
1.0
1.5
0.75
Dose. l/ha
Source: Danish Agricultural Advisory Service
Fungicide use stays close to the
optimum
TFI Fungicides
Winter
wheat
Spring
barley
Official
statistics
(2005-2007)
Target
0.71
0.34
0.65
0.35
CPO (trial
results)
0.7
0.4
Herbicides in cereals
• Herbicide performance is affected by
many biotic and physicochemical
factors such as:
– weed flora
– growth stage of weeds
– crop competitiveness
– climatic conditions
– application technique
– adjuvants
– the presence of other pesticides in the spray
solution
Efficacy profile for 60 weed species
DSS for weed control
DSS for weed control
Net yield loss compared
with optimum dose. dt/ha
Summary of 130 Danish field trials
on weed control in spring barley
Treatment Frequency Index
Source: Danish Agricultural Advisory Service
TFI Fungicides TFI Herbicides
Winter
wheat
Spring
barley
Winter
wheat
Spring
barley
Official
statistics
(2003-2005)
Target
0.71
0.34
1.32
0.99
0.65
0.35
0.95
0.70
CPO potential
0.7
0.4
0.7
0.5
• Why is the current herbicide use in
cereals onsiderably higher than the
targets?
– Because an integrated approach was
not adopted
• Decision-making for weed control is a
three step procedure
– Consider preventive measures such as
crop rotation or cultivation techniques to
reduce the potential losses due to
weeds
– Assess the need to apply herbicides
(threshold)
– Herbicide choice and dose rate
Monitoring for weeds is difficult and time consuming
Autonomous sprayer with weed sensor. The future?
• Conclusions:
– Only integrated pest control approaches
will be sustainable
– Integrated disease and insect control
can often be practised without major
changes in the cropping practice (1-year
perspective) .
– Integrated weed management often
requires major changes in cropping
practices (multi-year perspective)
Barriers for using thresholds and
DSS
”As little as possible.
as much as neccessary”
Factors influencing the optimal
theoretical pestice need
Management and
available
information
Spray capacity.
No. of hours to spray.
timing
Family. spare time.
holidays.
Other activities
on the farm.
animal. job?
Optimal pesticide
use in DK
1.7-2.3 TFI
Risk of crop failure
Scaling up trials to fields
Problematic areas.
limited harvest capacity.
Employees.
education.
working hours
Climate changes.
unknown factors.
Poor control
experiences
Price
relations
What do growers want?
•
•
•
•
Reliable and robust solutions
Economically sound solutions
Simple and easy messages
A dialogue with advisors
If they should do something else; they need
incentives!
Jokers!
• Increasing problems with fungicide
resistance
• Limitations in available fungicides (DK has
no chlorothalonil, prochloraz)
• Registration of ”heavy-loaded fungicides”
triazole mixtures!
• Climate changes have been estimated to
increase disease risk and TFI