Moving away from Chemicals for Pest, Disease and Weed ......The four pest management toolboxes...

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Moving away from Chemicals for Pest, Disease and Weed

Management

Dr Charles ‘Merf’ Merfield

The BHU Future Farming CentrePermanent Agriculture and Horticulture

Science and Extensionwww.bhu.org.nz/future-farming-centre

The BHU Future Farming CentrePermanent Agriculture and Horticulture: Science and Extension

Physical Chemical

Biological

The four pest management toolboxes

Ecological(Cultural)

Integrated Pest

Management (IPM)

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Pest management for last 70 years

Chemical


The future of pest management

EcologicalBiological

Physical

Chemical

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Biology and Ecology

Steve and Alison have covered biology and ecology

Now for some physics

Physics

Mesh crop covers - FFC research on mesh for tomato potato psyllid (TPP) control on potatoes

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TPP control

0

50

100

150

200

250

300

350

400

450

500

Control Chemicals Mesh 0.7mm Mesh 0.4mm Mesh 0.3mm

Nu

mb

er

of

TPP

Average total TPP caught on yellow sticky traps

Average total TPP on five leaf sample

a

a

b b b

312.5

403.5

1.0 1.3 0.8

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Yield of > 60 g tubers

60.069.6

78.786.5 85.3

0

10

20

30

40

50

60

70

80

90

100

Control Agrichemicals Mesh 0.7 mm Mesh 0.4 mm Mesh 0.3 mm

Yie

ld t

on

ne

/ h

a

a

b

bc

c c

24% increase from mesh over agrichemicals

Nearly any pest on any crop

Cabbage root fly

Flea beetles

Weevils

Carrot root fly

Shield bugs e.g., GMSB

Caterpillars

Potato tuber moth

Vertebrate pests

Impossible with chemicals

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Mesh on perennial crops

Chouinard, G., Firlej, A. & Cormier, D. (2016). Going beyond

sprays and killing agents: Exclusion, sterilization and

disruption for insect pest control in pome and stone fruit

orchards. Scientia Horticulturae, 208, 13-27.

Physical weed control

Physics is the main non-chemical weed toolbox

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Electrothermal weeders

Uses high voltage electricity to boil the water inside the plant

Cells explode from the inside

Biochemistry completely destroyed

Catastrophic tissue failure - zero chance of recovery

Thermal effect - impossible to evolve resistance


Electrothermal mode of action

True stem

Cotyledon leaves

Hypocotyl

True roots

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Systemic

mode of

action



Selective

mode of

action

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Photo Dr Mike Diprose



Broad acre

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Light - spectral filters

Many insects and diseases use / need specific wavelengths of light

– Aphids - yellow and UV bands to detect plants and orientate to the sky

– Fungal diseases, e.g., Botrytis cinerea and Alternaria solani need UV light to sporulate

Potatoes grown under UV blocking mesh - very little blight

Control - no mesh - lots of blight

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ECONET 0.15 × 0.35 mm hole mesh No mesh

54 tonne ha - 40 kg / 10 m row 8 tonne ha - 6 kg / 10 m row

TPP, mesh and UV light

When TPP gets under mesh it sulks - mesh blocks UV…..

When we really dial down UV light, psyllid yellows almost stops

What happens when we dial up the UV?

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UV light off UV light on

99.9% of TPP were collected on traps with UV light

14 times more on UV - 1,300% increase

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Conclusions

A smorgasbord of physical pest, disease and weed management techniques

The chemical toolbox is loosing tools and very few new ones are being found

The physics, biology and ecology toolboxes are having new tools added at an exponential rate

You need to understand and start using the new tools ASAP.

Moving away from Chemicals for Pest, Disease and Weed ......The four pest management toolboxes...

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