Pesticides for cocoa: Saviour, interim Solution or Side-track?

Roy Bateman, Prakash Hebbar

RPB: Pestic_Paris06: v.1.1

Developing Good Agricultural Practice (GAP) in cocoa

Many cocoa farmers decide to use pesticides

…some of which (especially insecticides) are toxic

They are often applied highly inefficiently

The fastest, most obvious way to mitigate this situation is:

– better selection of control agents

– more efficient application

Pesticides: the issuesResidues, MRLsWithdrawal of traditional compounds under EU/91/414 etc.- What do we replace them with?Application: operator safetyFarmers’ skills (cost effectiveness)Environmental concerns (perception and actual impact)

Scientific Approach:Rational Pesticide Use (RPU)

How to spray?

What to apply?

When?

targeting …

Collaborators: Field sitesEcuador: INIAP Moniliophthora (2 spp.)Brazil: CEPLAC, Almirante M. perniciosaCosta Rica: CATIE/CABI M. roreriCameroon: IRAD P. megakaryaGhana CRIG ? Mirids ?Indonesia: Prima, Sulawesi CPB

BLRS Sumatra CPB + Helopeltis

Developing capacity to improve local production, formulation and application of bio-control agentsApplication and evaluation of chemical control agents

Black pod fungicides: PHIs, residues, costs?

do not use within 30 days of harvest

INIAP 2005 / 06

• Evaluation of chemical and biological agents on Moniliophthora diseases

• Active spore traps to improve timing of application?

Rio Lindo 2005: wet weight

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copper hydroxide flutolanil azoxystrobin

oxycarboxin clorothalonil mixed regime

controls

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**: copper hydroxide (c.f. controls): increase in dry wt. 283 Kgif value = $377; total costs = $149 ($45 fungicides)Profit = $228 / ha (benefit / cost = 2.7)

CPB: the Rational Use of Insecticides

“pesticides are ineffective at reducing [CPB] infestation”

92% of Sulawesi farmers (that spray insecticides for CPB) can’t be wrong …

… or can they?

Insecticides that Sulawesi farmers spray

endosulfan16%

cypermethrin9%

deltamethrin3%

lambda-cyhalothrin21%

other pyrethroids1%

chlorpyrifos47%

other OP1%

carbamates2%

total pyrethroids: 34%

source: Hussin bin Purung

Field trial pre-requisites

Even stand of crop

Very good infrastructure

High pest population

Factorial:• insecticides x

application methods(+ controls)

• 2 stat. blocks (= divisions)

Factorial treatmentsApplication:

Side-lever knapsack (SK)Motorised mistblower (MM)

Insecticides:lambda-cyhalothrin (Matador)flufenoxuron (Cascade) “IPM”

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wasted: l-cyhalothrin MM wasted: controls

yield: controlsyield: l-cyhalothrin MM

August September October November December

Rambong Sialang: proportion wasted & yield

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Rain - crop cycle

Feb- May spraying• high Helopeltis populations• elevated proportion of CPB

infested pods (“trap crop”?)

Rambong Sialang: 10 year meansRising main crop

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Rainfall mm Cocoa tons CPB wasted 05 CPB wasted mean

Monitoring with pheromones

Evaluations at:Prima (Sulawesi)BLRS (Sumatra)

Trial design: overviewfactorial treatments to provide narrative on the relative efficacy of pesticide intervention strategies (and their cost effectiveness)

Control 2

Alwaysuntreated

IPM agent *

Manual (LK) sprayer

Broad spectrum insecticide

Manual (LK) sprayer

Control 1 (2005)“Toxic standard”- continuous paired sprays (from Mar. 06)

IPM agent: low toxicity & “soft”on NEs *

Motorised mistblower

Broad spectrum (BS) insecticide

Motorised mistblower (MM)

Control 2

Alwaysuntreated

IPM agent *

Manual (LK) sprayer

Broad spectrum insecticide

Manual (LK) sprayer

Control 1 (2005)“Toxic standard”- continuous paired sprays (from Mar. 06)

IPM agent: low toxicity & “soft”on NEs *

Motorised mistblower

Broad spectrum (BS) insecticide

Motorised mistblower (MM)

Pyrethroid If not IGR (flufenoxuron) then what?

Collaborative Bioassay network

Bioassays: the search for molecules and microbial agents

• Sharing (standardising) techniques:

• Insect rearing

• Application & assessment protocol

• Lab to field?

Conclusions (needs & opportunities)There is much to learn about the role of modern pesticides in IPM (“research vacuum” for 20 years).Are fungicides/insecticides cost effective in cocoa? Insecticides (against mirids, CPB etc.): perhaps the greatest priority for operator safety, residues, etc.Application: some practical research/evaluation needs, but mostly implementation / extension.Is application taking place at the right time?Ømonitoring with pheromones for CPB?Ø Active traps / assays for Moniliophthora spores

=> identifying effective measures for Good Agricultural Practice