Dr. Charles N Waturu Centre Director KARI-Thika P.O. Box 220, Thika, Kenya (email:karithika@africaonline.co.ke)
Title of Presentation The Status of the Bt-cotton Confined Field Trials in Kenya
Bt-cotton Experimental Phases Phase I- Baseline Arthropod Survey Phase II-Screen-house Evaluation Phase III-Confined Field Trial
Purpose of Bt-cotton Introduction Experiment Bt-cotton with Cry IAc Prot Active on Lepidopteran insects Aim to establish efficacy of protein
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
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 Others=stainers, whiteflies, aphids and Mites IPM best for cotton pests
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
Chewing Pests Important Cotton Pests o African bollworm H. armigera o o Spiny bollwom E. insulana/biplaga o Pink bollworm P. gossypiella o Cotton leafworms Spodoptera sp.
Important Cotton Pests Bollworm larvae on Square
Important Cotton Pests Bollworm on Cotton Boll
Important Cotton Pests Bollworm Damage
Important Cotton Pests Semi-looper and Damage (Sporadic)
Important Cotton Pests Sucking o Pests ored Spider Mite Tetranychus spp. o Jassid Empoasca spp.
Important Cotton Pests Sucking Pests oaphids A. gossypii owhitefly B.tabaci Cotton stainers Dysdercus spp
Baseline Arthropod Survey Phase I Pre-introduction baseline Characterization and quantification of arthropods
Objective Establish a reference baseline for arthropod diversity for comparison with studies after introduction of Bt-cotton
Methodology Sticky and Water traps Pitfall trap
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
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
Screen-house Evaluation Phase II Screen-house Evaluation of NuCotn 35B For Impact on African bollworms and Nontarget Arthropods
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
Methodology
Results No direct/indirect effect on Tricho spp. No effect on Aphids Effective on African bollworms
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 Nontarget Species
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
Methodology Test Varieties DP 448B-Bt Cotton DP 404BG-Bt Cotton DP 5415-Isoline DP 4049-Isoline HART 89M-Local commercial variety
Methodology Treatments Code Treatment Details A DP 448B Un B DP 448B Treated 6 times for sucking pests C DP 404BG Un D DP 404BG Treated 6 times for sucking pests E DP 5415 Un F DP 5415 Treated 6 times for sucking pests G DP 4049 Un H DP 4049 Treated 6 times for sucking pests I HART 89M Un J HART 89M Treated 6 times for sucking pests
Methodology Variety Characteristics Characters DP 448B DP 404 BG NuCOTN 35B HART 89M Leaf shape Normal Normal Palmate Palmate Leaf color Dark green Dark green Light green Medium-green Leaf hairiness Semi hairy Semi hairy Smooth/semi smooth Semi hairy Plant shape Conical Conical Conical Conical Flower color Yellow Yellow Cream Cream Pollen color Creamy Creamy Creamy Creamy Ball size Medium Med-large Medium Large Maturing time Medium season Medium season Medium season Medium season Fibre quality Good Good Good Good Fibre yield High High High High
Methodology Experimental 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 @ 30 x 100cm 12m buffer of commercial variety Blue corner pegs Biosafety requirements of site observed
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
Data Analysis Treatments denoted with codes Counts data transformed (SQR of X+1) 2 way ANOVA Student Newman Keuls (SNK) test Data presented tabular and graphical
Results Bollworm Larvae Survival 30 25 Mean Bollworm Larvae 20 15 10 5 0 DP 448B un DP 448B DP 404BG un DP 404BG DP 5415 un DP 5415 DP 4049 un DP 4049 HART 89M un HART 89M Varieties
Results Damaged Squares 80 70 60 Mean Damage Squares 50 40 30 20 10 0 DP 448B un DP 448B DP 404BG un DP 404BG DP 5415 un DP 5415 DP 4049 un DP 4049 HART 89M un HART 89M Varieties
Results Semi-looper Larvae Survival 100 90 80 Mean Semi-Looper larvae 70 60 50 40 30 20 10 0 DP 448B un DP 448B DP 404BG un DP 404BG DP 5415 un DP 5415 DP 4049 un DP 4049 HART 89M un HART 89M Varieties
Results Aphid Survival 500 450 400 350 Mean Aphids 300 250 200 150 100 50 0 DP 448B un DP 448B DP 404BG un DP 404BG DP 5415 un DP 5415 DP 4049 un DP 4049 HART 89M un HART 89M Varieties
Results Ladybird Beetle Larvae Survival 40.00 35.00 30.00 Mean Lady birds 25.00 20.00 15.00 10.00 5.00 0.00 DP 448B un DP 448B DP 404BG un DP 404BG DP 5415 un DP 5415 DP 4049 un DP 4049 HART 89M un HART 89M Varieties
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