Roy BatemanInternational Pesticide Application Research Centre,

Adrian Arnold, Cleber Bonina, Prakash Hebbar, Belinda Luke, Alan Pomella, Givaldo Niella

Delivery systems for fungal control agents(emphasising the importance of production quality control)

RPB delsys_cocoa: v.1.2

... gaining acceptance for environmentally-sound acridid control

12 years of development (and £10.2 M)

The importance of:n Identifying truly effective isolates

n Laboratory to fieldn Delivery systems, “enabling technologies”

n “Pre-field” test design, field trial programme

n Field to marketplace

Product development

Scientific research

Practical verification

“Enabling technologies” derived form the LUBILOSA Programme

n Techniques for identification of virulent isolatesn Mass production systems: pilot and commercialn Spore separation and packaging

n Formulations (oil-based and others)

n Application methods

n Storage techniques and models

n Field testing techniques

n Registration and licensing

Management of invasive cocoa diseases

using Trichoderma spp.... and others?Phytophthora megakarya

Crinipellis spp.

C. roreri C. perniciosa

… a promising biological agent for diseases caused by Crinipellis spp.

Trichoderma stromaticum

(with Hypocrea stromatica)

lumpy

Delivery systems …

The Nozzlehead view:

biopesticides are all just particles that must be delivered to their biological target as evenly and effectively as possible

The evil Dr. Mucus Spleen

©D

avid

Par

kins

… Preferably as single conidian Stokes’ law (particle size most important):

n Prevent settling in spray tankn Easier to formulate

n Optimise dispersion in spray droplet spectrum (therefore on the target)

D2 - 23

0

5

10

15

10 100 1000droplet diameter (µm)

% in

32

size

cla

sses

stromata

Aerial conidia are robust and effective

2 stage process, with grains (often rice) in bagstime consuming, expensive but …

Formulation problems common

MycoHarvester Mk. I

Tested with:Metarhizium etc.T. harzianum, T. asperellumT. stromaticum

T. stromaticum production at CEPLAC

Existing preparation

• Low particle size quality (nozzle blockage)

• Ground up rice: difficult to dry

• Poor shelf life

Need the spores not the substrate!

application

Inoculationand fermentation

formulationpacked in

polyethylenebags

Drying and grinding

pre-mix

dilution withwater

Production - delivery sequence (T. stromaticum)

application

Inoculationand fermentation

Surface drying only

dilution

Production - delivery: upgrade

Surface drying only

improved formulationsand/or adjuvants?

Thorough drying andpackaging (foil sachets)

Spore separation

Formulations

n Provisional (using adjuvants?)

n Optimised (higher technology: OF, WG?)

n Requirements:Stable, evenly dispersed TC, small particles (individual conidia?)

‘MycoHarvester’ Mk III

Internal mechanism

Particle size: quality assessment

Particle size analysis

T. stromaticum MH III (CEPLAC)(suspension in water)

0

25

50

75

100

1 10 100

particle diameter (µm)

cum

ula

tive

% in

cla

ss

MH3: sample 1

MH3: sample 2

Laboratory prototype

T. stromaticum (FA 64) MH4(suspension in water)

0

25

50

75

100

1 10 100

particle diameter (µm)

cum

ula

tive

% in

cla

ss

FA64, Mk IV,Plate 0FA64, Mk IV,Plate 5

Trichodermasuspensions

Spore separation also enables: 1. easier drying

Moisture analyser

Spore drying cabinet

Tri-laminate Al. foil sachet containing dried conidia

Bag sealing machine2. Packaging & storage

log10 σ = KE - Cwlog10m - CHt - CQt2

KE (6.3) absolute longevity extrapolated from value of log10 σσ at 1% mc

Cw (3.06) describes effect of mc on longevity

CH (0.00176) and CQ (0.000703) describe the effect of

temperature on longevity

t temperature

m moisture content (% wb)

Shelf life model (Hong et al.)

Model verification (Metarhizium)

a

0 20 40 60 80 1000

20

40

60

80

100

b

0 20 40 60 80 100

3 years

up to 1year

6 years

4years

5 years2years

Predicted viability (%)

Actual Viability (%)

Act

ual

Via

bili

ty %

Viability indicator

Conclusions

n The surface properties of T. stromaticum are unusual, having both hydrophilic and lipophiliccomponents

n Major sources of variation should be removed when Trichoderma spp. and similar fungi, are separated as single conidia using the ‘MycoHarvester’. This has significant implications for:- formulation- storage- ease of application …

n … and therefore experimental results.

Further information …

http://www.dropdata.net

Acknowledgements

USDAMasterfoods

CEPLAC