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
0
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23-F
eb
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ar
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copper hydroxide flutolanil azoxystrobin
oxycarboxin clorothalonil mixed regime
controls
**
**: 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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aste
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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
������
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
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