Rothamsted Researchwhere knowledge grows

Rothamsted Researchwhere knowledge grows

Managing Pests with Fewer Pesticides

Toby Bruce

“High yielding varieties”

really ?

Toby J. A. Bruce J. Exp. Bot. 2012;63:537-541

© The Author [2011]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Factors influencing crop protection in an agro-ecosystem

Bruce (2011) J. Exp. Bot. 63: 537-541

fewer effective

pesticides

legislation

reduced discovery and

approval of new products

rapid evolution and

spread of resistant biotypes

short generation

time

high reproductive rate

easy dispersal

global trade

consumer demand to

replace pesticides

Factors influencing crop protection in an agro-ecosystem

fewer effective

pesticides

reduced genetic diversity in crops

THRIVING PESTS AND HIGH CROP

LOSSES

climate change can make conditions better for pests

less intrinsic resistance to insects and

pathogens, and less competitiveness with

weeds

fertilised crops more nutritious to insects

and pathogens

broad spectrum pesticides kill

natural enemies of pests

Bruce (2011) J. Exp. Bot. 63: 537-541

Factors influencing crop protection in an agro-ecosystem

Promoting IPM and use of alternatives

2009/128/EC on the Sustainable Use of Pesticides

Reducing risks and impacts of

pesticide use on human health

and environment

Development of “Alternatives” is urgently needed

Development of “Alternatives” is urgently needed

Why is it needed?

Will future demand be met?

19611964

19671970

19731976

19791982

19851988

19911994

19972000

20032006

20092012

20152018

20212024

20272030

20332036

20392042

20452048

0

1000000

2000000

3000000

4000000

5000000

6000000

7000000

8000000

9000000

10000000

Popu

latio

n (1

000s

); Ce

real

Pro

ducti

on (x

500

tonn

es)

Source: FAOSTAT

human population

cereal production

Bruce (2010) Food Security 2: 133-141

To keep pace with growing demand,

global food production needs to increase by an estimated 70% by

2050 [United Nations]

New directions for 21st Century Agriculture

Royal Society: “There is a pressing need for the ‘sustainable intensification’ of global agriculture in which yields are increased without adverse environmental impact and without the cultivation of more land”.

Royal Society (2009) Policy document 11/09

A second green revolution which is knowledge intensive rather than input intensive?

Agronomy Resistant crops Enhancing Biocontrol Improved targetting RNAi

Information and data sharing Improved targeting Intelligent agriculture

Crop protection from pests – new directions are needed

Integrated Pest Management (IPM)

host plant resistance

IPM

biological control

pesticides

Tactics are more effective when used in combination and resistance is less likely to evolve

Biological control of pests - either by release in glasshouses or encouraging natural populations outside.

Biocontrol• Proven success in greenhouses with artificial release

• Conservation biocontrol strategies needed in outdoor cropping environments– Growth rate and arrival rate slower than pests– Can arrival be speeded up?

Biocontrol in edible protected crops 2010/11 (UK)

Aphidius ervi used on 2072 ha: 350 ha tomatoes, 131 ha of cucumbers, 1511 ha of peppers

Data from Fera Pesticide Usage survey (ha are treated hectares and include repeat treatments)

Aphidius colemani used on 3160 ha: 2235 ha peppers, 487 ha of cucumbers, 426 other vegetables

Conservation biocontrol: preserving what is already out there

Biocontrol opportunities

Develop attractants for natural enemies as part of an IPM strategy (lure and reward)

Develop attractants for pests as part of an IPM strategy (lure and kill)

Orange wheat blossom midge

Resistant varieties

Oakley et al 2005 HGCA Project Report No. 363

Now approx. 60% of UK wheat is resistant

Resistant varieties

• Females lay eggs, but larvae die when they start to feed

• A wound plug is formed at the feeding site due to lignification

• Antibiotic action of phenolic acids by the grain

Wound plug

Lignification process

OCOC3H7

OCOC3H7

2,7-nonanediyl dibutyrate

Sex pheromone

Monitoring systems

• Allow rational use of pesticides

• Need based applications save costs and importantly slow down the development of resistance

• sex pheromone traps:

- provide a solution to the detection problem

- enable more accurate and effective spray timing

Bruce et al. (2007) Pest Man. Sci. 63: 49

Bruce et al. (2007) Pest Man. Sci. 63: 49

pheromone traps are now commercially available to wheat growers in the UK

Monitoring systems

Is wheat at the ear emergence growth stage?

NOYES

Check pheromone traps. Are catches > 30 per day?

Is it at an earlier stage?

Check traps later when boots split

Crop is no longer vulnerable when flowering starts. Collect in traps

Keep checking traps daily until flowering starts…

Treat wheat fields in the surrounding area as soon as possible (females can fly to other nearby fields).

Are you growing a midge resistant variety?

YESNO

No further action needed

(i.e. no need for monitoring traps or insecticide treatment)

Pheromone traps need to be put up before ear emergence in fields where wheat was grown in previous years – these fields are sources of the pest [if growing susceptible varieties].

YESNO

NOYES

Are catches > 120 per day

NOYES

Assess wheat ears in field in evening. Spray if >1 midge on 6 ears

Wheat midge decision support

Web-based spray forecasting system incorporating MET data and crop growth stage

Fields AT RISK when there are 2 consecutive days with temperature at or above 20C at pod set (50% pods at 2cm)

http://www3.syngenta.com/country/uk/en/AgronomyTools/Pages/BruchidCast.aspx

You get this twice a week

during the season

4-Methylheptane-3,5-dione

Beauveria bassiana spores adhering to Entostat particles

Sitona lineatus adults

♂ produced aggregation pheromone that attracts ♀s and ♂s

Team: Toby Bruce (PI), Lesley Smart, Janet Martin

Lure-and-kill of pea and bean weevil, Sitona lineatus

The Lure: Aggregation pheromone: 4-methyl-3,5-heptanedione• Male produced• Attract both sexes of Sitona lineatus• Monitoring system: pheromone-based traps

(Blight et al., 1984; Glinwood et al., 1993)

The killing part: Entomopathogenic fungus: Beauveria bassiana• Naturally present in the soil• Known to kill S. lineatus insects, when infected

(Feng et al., 1994; Maurer et al., 1997; Poprawski et al., 1988)

4-methyl-3,5-heptanedione

Monitoring trap

Lure-and-kill technology:1. The aggregation pheromone & the pathogenic fungus

combined in a device2. The attracted insects will be coated with spores of the

fungal disease3. When they leave the device, the weevils will spread the

pathogen to others insects of the same species

Lure-and-kill of pea and bean weevil, Sitona lineatus

Field testing lure formulations

42

09-mar

s

13 18/20

23 27 1-2 Apr

7 9 10 13 15 170

20

40

60

80

100

120

140

160

180

A = Blank B = standard lure C = synthetic 1% D = synthetic 3% E = natural 1% F = natural 3%

tota

l/4

trap

s

Treatment F traps was the most effective lure

Traps were able to attract weevils during the whole trial period whereas the lure’s release rates were only measurable for 2 days in the lab

Mortality assessment with Beauvaria bassiana formulations

43

3-5 jun 5-8 jun 8-11 jun

11-15 jun

15-19 jun

19-23 jun

0

10

20

30

40

50

60

Control Entostat 1gINS 0.5g B1 2gB1 0.633g B1 0.2gB1 0.063g B1 0.02g

3-5 jun

5-8 jun

8-11 jun

11-15 jun

15-19 jun

19-23 jun

0

10

20

30

40

50

60

Control Entostat 1g INS 0.5gB2 2g B2 0.633g B2 0.2gB2 0.063g B2 0.02g

Click icon to add picture

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Team: Toby Bruce (PI), Jon West, Stephen Moss

http://croprotect.com/

TARGET MENTIONSAphid 35Slugs 32Black grass 30septoria 27yellow rust 19cleavers 16cabbage stem flea beetle 15light leaf spot 15fusarium head blight 14annual meadow grass 13brome 13charlock 13phoma 13pollen beetle 12sclerotinia 12wild oats 12chocolate spot 11brown rust 10dock 10early blight (alternaria) 10bruchid beetle 9chickweed 9Nematodes 9net blotch 9rhynchosporium 9cranesbill 8leatherjackets 8pea & bean weevil 8powdery mildew 8barley yellow dwarf virus (BYDV) 7broad leaved weeds (generic BLW) 7crown rust 7late blight (phytophthora) 7mayweed 7orange wheat blossom midge 7ryegrass 7thistles 7turnip yellows virus (TuYV) 7downy mildew 6fat hen 6knotgrass 6michrodochium 6redshank (weed) 6take all 6wheat bulb fly 6woodpigeon 6

Big data – the power of mapping in time and space

Hugh Oliver-Bellasis, 3 Nov 2015

Resistant crops

Labandeira (2013) Curr. Opin. Plant Biol. 16: 414

400 Million years of Coevolution

Agriculture can learn lessons from the wild plants and ecosystems

Conclusions – what to do?

Crop protection is becoming increasingly difficult - but that means farmers need professional agronomists even more!!

• Diversify crops and protection strategies– Not just pesticides – more IPM– Include resistant crop cultivars– Use biocontrol more– Prevention instead of cure?

• Monitor pests/weeds/diseases– Expect rapid developments in surveillance systems

• Share information www.croprotect.com