Soil, Soil, Toil and Trouble

What Lurks Beneath

Dr Glynn Percival

Bartlett Tree Research Laboratory

R&D Lab – Charlotte USA

Bartlett Tree Research Laboratory,

University of Reading Clients

SITES Clients

Dying Trees and Shrubs

Box blightSymptoms of box blight

Where do you start?

Soil Sampling

Soil

nutrient

analysis and

prescription

fertilisation

FERTILISERS

Modes of application

Percolation test

Drainage Analysis

Soil profileSOIL COMPACTION

EVALUATION

Decompact

End resultBefore After

Soil

nutrient

analysis and

prescription

fertilisation

Boron Contaminated Soils

So how do you remediate soils high in boron and heavy

metals?

Puccinellia frigida

Strategic Planting of Accumulator Plants

Heavy Metal Removal (mg/Kg of soil ) By Accumulator Plants

2015 2016 2017

Boron 19.0 17.1 15.8

Copper 9.2 8.8 8.3

Zinc 80.4 77.4 72.5

Three aspects of soils1. Chemical: pH, macro and micronutrients

2. Physical: Structure/compaction/silt:sand:clay

ratios

3. Biological: Soil is a very complex “living organism”

There are more microorganisms in a handful of soil

than there are people on earth.

Soil is at the bottom of the food chain, yet it is the cornerstone of life on earth.

Testing for soil biological activity

Worm test: 0-2 = Low biological activity

2-4 = Medium biological activity

5-8 = Acceptable biological activity

9-10 = High biological activity

Honey Fungus

.

0

1

2

3

4

5

6

RCX Control RCX Control

Co

nd

itio

n R

ati

ng

(1-5

)

Vineyard 1Vineyard 2

Plant condition higher in RCX treated vines

Baumgartner K (2004) Plant Disease 88:1235-1240. RCX + Biochar

A purified form of charcoal.

When added to soil it:

Increases CEC

Improves water retention

Improves fertiliser effectiveness

Soil Management –

Biochar

Benefits are now realised.

BiocharOrganic material pyrolysedat temperatures in excess of 350°c

Biochar

Vinca and Gardenia inoculated with Phytophthora

Control Compost Biochar

Acts as a haven for mycorrhiza

Slides courtesy of J MacPhail

Mycorrhizae trapping nematodes with their filamentous hyphae

Slides courtesy of J MacPhail

Biochar effect on leaf blotch and leaf miner severity

GrowChar

0.25kg m2

GrowChar 0.50kg m2

Control

Bio-Control - Trichoderma

Fungi in the genus Trichoderma have been recognised since

the 1920s for their ability to act as bio-control agents against

both root and foliar plant pathogens. When added to the soil

and come into contact with tree roots, Trichoderma rapidly

colonize the root surface or cortex, depending on the strain. In

addition to colonizing roots, spp. attack, parasitize and gain

nutrition from other fungi.

RCXApply Trichoderma

Protect the root collar

Use of physically inert compounds such as perlite, vermiculite, sand etc., that are suitable for root but not rhizomorph growth and development.

Question. What makes a successful disease a successful disease?

Plant Defence Activators (PDA’s) PDA’s “switch on” a plant's own defence mechanisms by

treatment with either a biological or chemical agent.

Commercially available PDA’s.Messenger (a.i. Harpin protein) in the US.Bion (BTH) in Europe.Agri-Fos (a.i. Potassium phosphite) in Australia and the US .Rigel (a.i. Salicylic acid analog) in the UKOryzemate (a.i. Probenazole) Japan.

Changes in tree physiology:

1. Accumulation of antimicrobial proteins, fungi-toxic

derivatives and antimicrobial fatty acid.

2. Increase in plant antibodies (phytoalexins)

3. Leaves become thicker and more resistance to

enzymatic degradation

4. Enhanced resin production, synthesis of new

phenolics and initiation of a wound periderm.

5. Alteration of the topography of the leaf surface thus

interfering with fungal recognition of host

penetration sites

Control

Fungicide

Messanger

Control

Fungicide

MessangerResults of several

years of trials show

PDA’s can reduce

disease severity by 60-

70%.

Mulching

Research Plan

Experiments used containerized stock of horse

chestnut (Aesculus hippocastanum) – highly

sensitive to Phytophthora root diseases.

Inoculation

Each potted plant was inoculated with twelve rice grains colonized

by P.cactorum.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Control F.sylvatica Q.robur Q.ilex P.avium B.pendula C.monogyna

Dis

ease s

everi

ty

The influence of pure mulches on disease severity of Phytophthora root rot

***

***

Willow mulchNo mulch Willow mulch

Number Trees Re-Infected

0

1

2

3

4

5

6

7

8

Control Treated

Improvements in Tree Health

Oak Processionary Moth –

Dangerous to humans

My favourite tree

Thank

You