Dr' Charles N Waturu

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Dr. Charles N Waturu Centre Director
KARI-Thika P.O. Box 220, Thika, Kenya
(emailkarithika_at_africaonline.co.ke)
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Title of Presentation

• The Status of the Bt-cotton Confined Field Trials
  in Kenya

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Bt-cotton Experimental Phases

• Phase I- Baseline Arthropod Survey
• Phase II-Screen-house Evaluation
• Phase III-Confined Field Trial

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Purpose of Bt-cotton Introduction

• Experiment Bt-cotton with Cry IAc Prot
• Active on Lepidopteran insects
• Aim to establish efficacy of protein

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Transgenic Bt cotton

• Plants with transgene expressing Bt proteins
  toxic to Lep pests
• Bt proteins much more persistent and effective
• Bt toxins in plants reduce the need for
  insecticides
• Bt cotton one of the plants approved for
  commercial production

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Justification of Introduction

• Collapse of cotton production in Kenya
• Pest control take 32 of production costs
• African Bollworm most important cotton pest
• Can cause 100 yield loss if un-checked
• Synthetic pyrethroids for bollworm control
• Othersstainers, whiteflies, aphids and Mites
• IPM best for cotton pests

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Benefits of Bt-cotton

• Bt-cotton control bollworms
• Bt-cotton indirectly control sucking pests
• Increased activity of natural enemies
• Reduced spraying with pesticides
• Reduce environmental pollution
• No effect on beneficial insects
• Safe to human beings
• Chances of resistance reduced

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Important Cotton PestsChewing Pests

• African bollworm H. armigera
• Spiny bollwom E. insulana/biplaga
• Pink bollworm P. gossypiella
• Cotton leafworms Spodoptera sp.

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Important Cotton Pests Bollworm larvae on Square
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Important Cotton Pests Bollworm on Cotton Boll
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Important Cotton Pests Bollworm Damage
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Important Cotton Pests Semi-looper and
Damage (Sporadic)
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Important Cotton Pests Sucking Pests

• Red Spider Mite Tetranychus spp.
• Jassid Empoasca spp.

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Important Cotton Pests Sucking Pests

• Aphids A. gossypii
• Whitefly B.tabaci
• Cotton stainers Dysdercus spp

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Baseline Arthropod Survey

• Phase I
• Pre-introduction baseline Characterization and
  quantification of arthropods

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Objective

• Establish a reference baseline for arthropod
  diversity for comparison with studies after
  introduction of Bt-cotton

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Methodology
Sticky and Water traps
Pitfall trap
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Methodology

• Districts covered Meru, Kitui, Malindi, Kirinyaga
• Trapping methods-direct counts and water, pitfall
  and sticky traps
• Trapped arthropods recovered every week for 4
  weeks.
• Arthropods sampling on plants conducted for 4
  weeks.
• Preserved specimens identified at the NARL

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Results

• Arthropods recovered in orders Hymenoptera,
  Coleoptera, Homoptera, Lepidoptera, Acarina,
  Hemiptera and Diptera.
• Arthropods in these orders included important
  cotton pests and natural enemies.
• Reference collection of voucher specimens of
  species of various taxa maintained

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Screen-house Evaluation

• Phase II
• Screen-house Evaluation of NuCotn 35B
• For Impact on African bollworms and Non-
• target Arthropods

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Objectives

• Verify direct (bitrophic) effect on Tricho spp.
• Verify indirect (tritrophic) effect on Tricho
  spp.
• Verify effect on A. gossypii
• Verify efficacy on African bollworms

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Methodology
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Results

• No direct/indirect effect on Tricho spp.
• No effect on Aphids
• Effective on African bollworms

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Confined Field Trial (CFT)

• Phase III
• Field Evaluation of Transgenic Bt-Cotton
• DP448B and DP 404BG for Efficacy on
• African Bollworms and its Impact on Non-
• target Species

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Objectives

• Effect of Bt-cotton on natural enemies
• Risk of intercrossing with the Bt-cotton
• Evaluate economic advantage of Bt-cotton
• Efficacy on African Bollworms
• Impact on other arthropods

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Methodology

• Test Varieties
• DP 448B-Bt Cotton
• DP 404BG-Bt Cotton
• DP 5415-Isoline
• DP 4049-Isoline
• HART 89M-Local commercial variety

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Methodology Treatments

• Code Treatment Details
• A DP 448B Untreated
• B DP 448B Treated 6 times for sucking pests
• C DP 404BG Untreated
• D DP 404BG Treated 6 times for sucking pests
• E DP 5415 Untreated
• F DP 5415 Treated 6 times for sucking pests
• G DP 4049 Untreated
• H DP 4049 Treated 6 times for sucking pests
• I HART 89M Untreated
• J HART 89M Treated 6 times for sucking pests

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Methodology Variety Characteristics
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MethodologyExperimental design and
layout

• Experimental Design RCBD
• 4 replications
• 10 treatments
• 5 x 5m plot size
• 3m between blocks
• 2m between plots within block
• 70 plants per plot _at_ 30 x 100cm
• 12m buffer of commercial variety
• Blue corner pegs
• Biosafety requirements of site observed

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Data Collection

• Counts of target and non-target pests
• Counts of damaged squares
• Counts of natural enemies
• Arthropod diversity
• Harvested boll count
• Seed-cotton yield
• Seed sampling for PMG
• Costs and yield data for economic study

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Data Analysis

• Treatments denoted with codes
• Counts data transformed (SQR of X1)
• 2 way ANOVA
• Student Newman Keuls (SNK) test
• Data presented tabular and graphical

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Results Bollworm Larvae
Survival
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Results Damaged Squares
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Results Semi-looper
Larvae Survival
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Results Aphid Survival
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Results Ladybird Beetle
Larvae Survival
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Bt Cotton Project Output

• Efficacy on African bollworm established
• No effect on egg laying
• Lower square damage for Bt-cotton
• Efficacy on Semi-looper established
• No impact on key natural enemies
• No impact on other arthropods
• PMG established
• Bt-cotton give better returns

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THANK YOU