btme harrogate presentation january 012

Suppression of

Fusarium Patch By

Phosphite in Cool

Season Amenity

Turfgrasses

John Dempsey BSc

Curragh Golf Club

and

Centre for Research in Biosciences

UWE, Bristol

Course manager of Curragh Golf Course

BSc in Turfgrass science

Myerscough college

PhD in Biosciences – Uwe, Bristol

Suppression of Microdochium nivale

Infection by Phosphite in Cool-season

Amenity Turfgrasses

CONCLUSIONS OF THE

MYERSCOUGH STUDY

Phosphite

treatment-

Not metabolised

Improved

turfgrass quality

Reduced disease

Research Objectives

Phosphite reduce

Microdochium?

Field trials

Means of reduction

Direct or indirect?

Combination?

Microdochium active on Poa annua

PHOSPHITE

Form of phosphorus

P

Phosphate PO4Phosphite PO3

Not metabolised

in plants

PHOSPHITE

Suppresses phytopathogens

Oomycete pathogens

Pythium and

Phytophthora

Anthracnose

Improved turf quality

Microdochium in cereals

No research into

Microdochium and turfgrass

Agrostis canina canina

Agrostis stolonifera

Poa annua

Trial plots

120 2 x 2 m plots

Cut at 5mm

Maintained as

greens

GRIGGS TRIALS

PK Plus 20L ha-1

PK Plus 20L ha-1

Ultraplex 10L ha-1

Chipco 20L ha-1

Chipco 20L ha-1

PK Plus 20L ha-1

NPK Control

Untreated Control

Trials running since Sept 2010

Poa annua plots

Agrostis stolonifera plots

Agrostis canina canina plots

Agrostis canina canina plots

Mean values over two years

Agrostis canina canina plots – January 2011

CONTROL PK PLUS

Poa annua plots – January 2011

CONTROL PK PLUS

Agrostis canina canina plots – January 2012

Agrostis canina canina plots – January 2012

Agrostis canina canina plots – January 2012

Poa annua plots – January 2011

Poa annua plots – January 2012

Poa annua plots – October 2011

CONTROL PK PLUS

MEANS OF SUPPRESSION

• Inhibits pathogen

Direct

• Stimulates plants defences

Indirect

Combination of both

In Vitro Study

Microdochium

propagated from

infected turfgrass

Grown on and

used for in vitro

study

To assess

inhibition of

mycelial growth

AMENDED GROWTH MEDIA

Amended PDA

Range of

phosphite and

phosphate

From 0.5 μg/ml to

1000 μg/ml

Compared with

unamended

controls

Control + 4 days

Phosphate - 100 μg/ml + 4 days

Phosphite - 100 μg/ml + 4 days

Mycelial Growth on Amended PDA

Phosphite Phosphate Control

Hyphal morphology

Unamended 75µg/ml Phosphite

Hyphal morphology

Unamended 75µg/ml Phosphite

• Measure assimilation rate

• Track translocation

• Determine accumulation amounts

• Assess the fate

Targets

•Treat turfgrass

•Collect samples

•Six week period

•Analyse - HPIC

Methods

What happens when phosphite is applied to

turfgrass?

48 hours - 4889 ppm

Further Research

Field trials

In vitro

HPIC analyses

Infection

process in

turfgrass

Defence

processes

ROS

NO2

Phytoalexin

synthesis

Measure

salicylic acid

Systemic

Acquired

Resistance

Alternative means

to suppress

Microdochium are

required

Phosphite is

rapidly

assimilated and

translocated by

turfgrass

Phosphite treated

plants less

susceptible to

Microdochium

nivale

Phosphite has a

direct inhibitory

effect on mycelial

growth

Evaluate defence

processes –

ROS, NO and

salicylic acid

Inducible defence

mechanisms

Systemic Acquired

Resistance

Summary

Updates on Twitter - @J_J_Dempsey