Taming Major Maize Field Pests in Kenya: The Role of Biotechnology

Transcription

1 Taming Major Maize Field Pests in Kenya: The Role of Biotechnology Stephen Mugo and Simon Gichuki Presentation to OFAB, Jacaranda Hotel, Nairobi, Kenya, 30 th July 2009 Presentation made to STAK in support of IRMA III Bt Project on 24th June 2009

2 Outline of Presentation 1. Introduction 1. Insect pests in agriculture Stem borers global/africa/ Kenya 2. Stem borer and stem borer control 3. Bt technology (history, Use, Pro & cons) 2. The IRMA Project 1. Goal / Objectives 2. Approach Holistic (Product development, Science, Communication, Environment, IRM, and Impact Assesment) 3. Bt maize introduction and testing in Kenya 4. Achievements Results from testing public and private sector events 5. Looking into the future Sharing private events 6. Conclusions

3 Introduction Maize is an important crop in Kenya Kenya is a net importers of maize annually o Very low grain yields of only 1.5 t/ha o World average is 4.9 t/ha Insect pests in the field and in storage are among the factors that reduce yields and food availability in Kenya Despite the heavy loss few maize improvement programs include breeding for resistance o This is attributed to the genetic and logistical challenges posed by screening and selection for insect resistance. Farmers rely on other non genetic methods: cultural, or no control Chemical,

4 Losses of maize grain yield due to various stresses in the Developing world

5 Insect Pests in Maize Production Insect pest problem Part of agricultural ecosystem Affects 46% of global maize growing area Causes 10% world loss annually 52 million MT valued at $5.7 billion 60% of maize loss is in the tropics US$550 M worth of insecticide used annually Major species of maize pests The moth group (cutworms, earworms, stem borers, and grain moths) The beetles (rootworms, wireworms, grubs, grain borers, and weevils) Disease vectors (leafhoppers and aphids)

6 Major Maize Insect Pests 1. Field insect pests 1. Field insect pests Stem borer resistance (various species Cp, Co, Bf, Sc, Es) Stem borer resistance (various species Cp, Co, Bf, Sc, Es) 2. Post harvest (storage) insect pests 2. Post harvest (storage) insect pests Maize weevil (Sitophilus zeamais) Maize weevil (Sitophilus zeamais) Larger grain borer (Prostephanus trancatus) Larger grain borer (Prostephanus trancatus) Spotted stem borer Maize weevil Larger grain borer (LGB)

7 Damage of Maize Cobs by the Maize Weevil

8 Damage of a Maize Cob by the Larger grain Borer (LGB) LGB damaged cob

9 The Stem Borer Problem Chilo partellus larva Dead heart Stalk tunneling Loss of photosynthetic leaf area Dead hearts Lodging from damaged stems Increased ear rots and aflatoxins Reduced grain yields

10 Worldwide Distribution of Important Maize Stem Borer Pests Worldwide Distribution of Important Maize Stem Borer Pests European corn borer European corn borer Oriental corn borer Oriental corn borer Pink stem borer Pink stem borer Sugarcane borer Sugarcane borer Spotted stem borer Spotted stem borer African maize stalk borer African maize stalk borer Pink stem borer Pink stem borer African armyworm African armyworm Asian corn borer Asian corn borer Asiatic stem borer Asiatic stem borer Maize stem borer Maize stem borer African armyworm African armyworm Spotted stem borer Spotted stem borer Pink stem borer Pink stem borer Source: Source: Mihm Mihm, J.A , J.A Insect Science and its Application Insect Science and its Application 6:369 6: Southwestern corn borer Southwestern corn borer Sugarcane borer Sugarcane borer Fall armyworm Fall armyworm Neotropical Neotropical corn borer corn borer European corn borer European corn borer Fall armyworm Fall armyworm Corn ear worm Corn ear worm Root worm Root worm

11 Stem Borer Ecologies and Economies in Kenya 13.5% losses per year US$ million Crop loss from stem borers in Kenya (US$ million) Lowland Tropics Highlands Dry Mid-altitude and trans. Chilo partellus Busseola fusca Sesamia calamistis Eldana sacharrinna Chilo orichalcilielus Moist Mid-altitude Moist-transitional

12 Stem Borer Management Options Cultural control Chemical control Biological control Micro organisms Predators/parasites Host plant resistance Chilo partellus Conventional breeding Biotechnology mediated Marker assisted selection (MAS) Transformation Genetic engineering Integrated Pest Management: Combine two or more of these options

13 Plant Improvement Options Related and Unrelated Species Linkage Maps Functional Genomics GENES Conventional Selection Marker assisted Selection Genetic Engineering IMPROVED GERMPLASM

14 Chronology of Maize Improvement for Insect Resistance Pre 1970s 1980s 1990s 2000s Pest identification Methodology development for screening and breeding Biotechnology applications in insect pest control Deployment of the transgenic technology in maize production

15 Bt Technology Bt crystal proteins use in agriculture Bt Sprays Isolated and purified Bt crystal proteins, Breakdown in sunlight, Requires several applications, Controls surface feeding insects only and not burrowed insects, Expensive and used for high value crops only Bt delta endotoxins Engineered into crops, genes are modified to ensure stable expression within the plant, No need for sprays, Can control burrowed insects, Cheaper and easier to handle

16 Process of Creating Bt Crop Plants

17 Benefits of Genetically Enhanced Crops A. Increased production 1 Increased crop efficiency, 2 Protection from diseases, pests, & herbicides 3 Improved nutritional quality & marketability 4 Resistance to adverse soil and weather conditions 5 Develop agri ceuticals for improving health and environment B. Healthier Environment 1 Reduced herbicides use of 30 40%, 2 Reduced pesticide use of 30% 3 Reduced pollution in water sources 4 Bioremediation clean ups Summary 1 Increased productivity, 2 Conserving biodiversity 3 Efficient use of external inputs 4 Increased stability of production

18 Commercialized Bt Maize Genes and Events Bt Event Trademark Cry protein Promoter Expression Owner 1 Bt11 YiedGuard cry1ab CaMV 35S All tissue Syngenta 2 Mon810 Yieldguard cry1ab CaMV 35S All tissue Monsanto 3 TC1507 Herculex 1 cry1fa2 - - Mycogen Pioneer, Dow 4 Mon863 Yieldguard- Rootworm cry3bb CaMV 35S Roots Monsanto Knockout, cry1ab PEPC + Green tissue Syngenta Natureguard Pollen + Pollen 6 CBH351 Starlink cry9c CaMV 35S All tissue Aventis CropSci. 7 DBT418 BTXtra cry1ac CaMV 35S All tissue Dekalb Genetics 8 TC cry1fa2 CaMV 35S - DOW Agrosci. LLC 9 Mon802 - cry1ab - - Monsanto 10 Mon809 - cry1ab - - Monsanto

19 Why Bt Maize? 1. Conventional resistance is a quantitative (polygenic) trait difficult to handle and less efficient to transfer. 2. Bt resistance is based on one or two genes that are easier to handle and more efficient to transfer. 3. Using Bt technology would reduce the heavy reliance on chemical pesticides, which pose their own set of environmental and health risks. 4. Bt technology can be readily combined with other stem borer control methods and can fit well into an IPM strategy

20 Bt and Non Bt Maize Fields Non-Bt Bt Bt Non-Bt

21 The Insect Resistant Maize for Africa (IRMA) Project Goal To develop and deploy stem borer resistant maize varieties to resource poor farmers in Kenya Approach Technical, regulatory, proprietary, and stewardship issues were addressed.

22 IRMA Guiding Principles and Key Aspects Guiding principles Model of good practice (including biosafety aspects); Pilot project for public private partnership and cooperation; Employ state of the art technology and methodology; and, Transparent and open with ongoing stakeholder dialogue Key aspects Conventional (HPR) plus Bt strategies Effective public & private Bt events Baseline data on insect ecologies Feasible IRM strategies Communications and education

23 Communication and Documentation Farmers Scientists Govt Minister Media Workshops & seminars, Stakeholders meetings

24 Biosafety Facilities BS level 2 Bioassay Lab Quarantine Field Site Biosafety Level 2 Greenhouse

25 Insect Resistant Hybrids Vs. Checks Check SBR Resistant

26 Feb Jan Mar Dec Apr May 2004 Dec Feb Nov May 2007 Introduction of Bt Maize in Kenya Application for Bt maize leaf imports for Leaf bioassays Approval for introduction of Bt maize leaves from 1st generation events, imported and leaf bioassays from first generation events done Application for import permits for combinations of 1 st generation events Leaf from combination imported and leaf bioassays performed Application for imports of seeds from 2 nd generation events made Approvals of importation of seeds made and seeds introduced and evaluated in the BGHC Application for confined field trials Approval for confined field trial granted Application for introduction of MON810 Approval for MON810

27 Bt Genes and Events Introduced and Tested in Kenya First generation events Event 176 cry1ab PEPcar Event 5207 cry1ac ubiquitin Event 5601 cry1b actin Event 1835 cry1b ubiquitin Event 7 cry1ab 1B actin Event 602 cry1e actin MON810 cry1ab 35S Second generation events Event 3 cry1ba ubiquitin Event 6 cry1ba ubiquitin Event 10 cry1ba ubiquitin Event 58 cry1ba ubiquitin Event 93 cry1ba ubiquitin Event 127 cry1ba ubiquitin Event 216 cry1ab ubiquitin Event 223 cry1ab ubiquitin Event 396 cry1ab actin Private sector event MON810 cry1ab CaMV 35S

28 Testing Bt Maize Events in BGHC

29 Bt and non Bt plants Tested in Biosafety Greenhouse

30 Testing Bt Maize in Confined Field Trials at KARI Kiboko First season (LR 2005) Second season (SR 2006)

31 Leaf Bioassays on Bt Maize and Five Stem Borers Species

32 Stem Damage in Bt and Non Bt Maize Plants Non Bt Bt

33 Results from Leaf Bioassays in Public Events

34 Leaf Damage Scores from Chilo Partellus Stem Borer for Bt Maize Events Lead damage score (1-9) Event 3 Event 6 Event 10 Event 58 Event 93 Event 127 Event 216 Event 223 Event 396 CML Event 3 Event 6 Event 10 Event 58 Event 93 Event 127 Event 216 Event 223 Event 396 CML 216 Event and control

35 Leaf Damage in Field by C. Partellus on Bt Maize in Confined Field Trials at Kiboko 3.0 a Stem Borer Damage (Score: 1-9) bc b c c bc c c bc bc 0.0 Event 3 Event 6 Event 10 Event 58 Event 93 Event 127 Event 216 Event 223 Event 396 CML 216 Bt Maize Event

36 Larval Mortality in Leaf Bioassays of Bt maize in Confined Field Trials at Kiboko c abc ab ab d b ab ab ab bc bcd b a bcd ab a abc ab abc cd ab ab a ab ab abc a abc d c Mortality (%) Event 3 Event 6 Event 10 Event 58 Event 93 Event 127 Event 216 Event 223 Event 396 CML 216 Bt Maize Event Busseola fusca Eldana sacharrina Sesamia calamistis

37 Results and Discussion of Testing Public Bt Maize Events First generation Bt maize events showed control of Chilo partellus, C. orichalcocililiellus, Eldana saccharina, Sesamia calamistis by endotoxin from cry1ab, cry1ac, cry1ba and the fusion cry1ab cry1ba genes but no control by toxins from cry1e. Bt maize endotoxin from cry1ab and cry1ba from Bt maize grown in the greenhouse controlled Chilo partellus, E. saccharina, and S. calamistis. However, complete control was not observed in the laboratory and greenhouse for Busseola fusca.

38 Results and Discussion of Testing Public Bt Maize Events In the OQS, Leaf damage scores in the field showed that Bt maize effectively controlled C. partellus with mean scores of 1.2 against 2.7 for the non-bt CML216 control. Laboratory bioassays using leaves from the same plants showed control for E. saccharina and S. calamistis, with mean larval mortality of 64% and 92%, respectively. However, complete control was not observed for Busseola fusca.

39 Conclusions from Testing Public Bt Maize Events These results show that Bt maize will control three of the four major stem borers in Kenya These results also demonstrate the great specificity of Bt maize endotoxin even to different stem borer species. Additional Bt genes or events will need to be sought and tested for effective stem borer control in all maize growing ecologies in Kenya.

40 Testing Private Sector Bt Maize Events The public Bt maize events did not show control of the African stem borer (Busseola fusca Fuller): o An important stem borer species o Without B. fusca stewardship of Bt maize would be compromised by the possibility of rapid development of resistance to Bt delta endotoxins. Requests were made to several companies but only Monsanto offered Bt maize event MON810. Bt MON810 was therefore tested in 2008 as an option to control of all major stem borer species in Kenya.

41 Bt Maize Event MON810

42 Bt Maize Event MON810

43 Leaf Damage Scores from Bt and Non Bt Maize Plants Infested with Larvae of B. Fusca and C. Partellus at V6 and V8 Stages 4 DKC8073YG (MON 810-1) DKC8053YG (MON 810-2) Insect Damage Score DKC8053YG (Non-Bt) Event 223 Bt (Cry1Ab) 0 Leaf Damage Bf V6 Leaf Damage Cp V6 Leaf Damage Bf V8 Leaf Damage Cp V8 Varieties and leaf stage

44 Mortality in Bioassays of Bt and Non Bt Plants with 5 Stem Borer Species at V6 Stage DKC8073YG (MON 810)V6 DKC8053YG (MON 810) V6 DKC8053YG (Non-Bt)V6 Event 223 (Cry1Ab) V6 Mortality (%) Busseola fusca Chilo partellus Eldana saccharina Sesamia calamistis Stem Borer Species

45 Conclusions from Testing Bt maize Event MON810 The efficacy of MON810 against all four major stem borer species in Kenya was demonstrated in whole plant infestation and in leaf bioassays. Deploying Bt Maize Event MON810 may not pose risks of development of insect resistance However, Bt Maize Event MON810 is being replaced by Bt Maize Event MON89034 and this needs to be evaluated in Kenya.

46 The future Sharing Private Sector Events Yield Guard II (YGII) Event = MON Latest insect pest control technology Genes = Cry1A.105 & Cry2Ab2 Wider spectrum of lepidopteran pests More effective IRM tool Season long control Status = FDA approved = USDA approved = EPA approved = Being grown in USA, commercialized 2008

47 Sharing MON89034 Bt Maize Event A Private Private Public Partnerships for Delivery of Bt maize to farmers in Kenya in which: o Monsanto will avail Bt trait and germplasm to Kenya market through licensing interested seed companies o MON89034 trait will be integrated into selected KARI and CIMMYT maize germplasm to be availed to resource poor farmers in Kenya through some market segmentation system.

48 Towards Sharing MON89034 Bt Maize Event Agreements to facilitate use of MON89034 event 1. Trait integration of MON89034 to 13 CIMMYT and 8 KARI inbred lines a. Monsanto CIMMYT b. Monsanto KARI b. TI on going (BC3) in RSA 2. KARI Monsanto R&D agreement to test MON Licences between Monsanto and participating seed companies for trait 4. Licences between KARI and participating seed companies for germplasm

49 Concluding Remarks 1. Stem borers contribute significant loss of maize in Kenya 2. Biotechnology holds great promise in improving food production in Kenya 3. KARI and CIMMYT have enhanced capacity to test and develop Bt maize events from the Public and Private sectors 4. Bt maize event MON89034 holds promise for control of major stem borer pests in Kenya 5. An innovative way to share MON89034 by the private provider and other seed companies in private sector own germplasm and in public sector germplasm through market segmentation is planned to avail Bt maize to Kenyan farmers by 2013.