Bt Brinjal The scope and adequacy of the GEAC environmental risk assessment

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52 Bt Brinjal: The GEAC environmental risk assessmentThese values for the yield benefit of Bt brinjal are significantly less than thosesuggested by Mahyco and EC-II.The main reasons for this are that (1) Mahyco and EC-II did not consider how EE-1 Bt brinjal would be compatible withpresent brinjal production systems,and (2) they assumed that yieldsTable 4. Estimated expected maximum yield benefit from hybrid Bt brinjal to farmers inIndia based on a comparison to a similar non-Bt brinjal hybrid without any control ofobtained under controlled experimentalBFSB, using data from the MST and LST, yield gaps, and other factors related to Indianconditions accurately estimated yields production systems described above.on farm and ignored the scientificLocation Size of farm Proportion Maximum potentialliterature on yield gaps. Moreover, theyof farmers yield benefit (q/ha)did not adjust their estimates to reflectMST LSTtheir own data. Their estimates areWest Bengal, Mostly small-scale0.61 0 0based on the MST data. The newer Orissa, Bihar resource-poorLST data shows significantly lower Rest of India Large-scale commercial 0.04 84.2 43.7potential yield benefits from EE-1 Btbrinjal, yet their estimates have notbeen adjusted downward.Rest of India Small-scale resource-poor 0.35 13.9 7.2Even so, the low estimates presented here are likely to overestimate the actual yield benefits to India as a whole because itis unlikely that all farmers will adopt EE-1 hybrid Bt brinjal technology. There are three factors that may limit adoption. Asdiscussed above, hybrid Bt brinjal may not fit well with some of the large-scale commercial production systems that presentlyrely on open-pollinated varieties (OPVs), and is unlikely to fit into small-scale resource-poor production. In addition, hybridBt brinjal may be too costly for some farmers to afford to use. Lastly, the yield risk of using hybrid Bt brinjal may deter manyfarmers from adopting it. About 16% of the field trials showed hybrid Bt brinjal having no yield advantage over non-Bt brinjaleven when non-Bt brinjal had no control of BFSB. Many farmers are risk-averse and may not adopt hybrid Bt brinjal if the riskof no benefit is too high.In addition, the estimates are likely to be overestimates because the relevant control comparison for farmers is the Btvariety against the best non-Bt variety being used in a region. The control comparison used in the MST and LST was the Btvariety against a genetically similar non-Bt variety. The best non-Bt variety in a region is expected to have higher yields than agenetically similar non-Bt control variety used in the MST and LST experiments, and this also will reduce the estimated yieldbenefit of hybrid Bt brinjal. This serves to reiterate previous points about the limitations of the data from the MST and LSTexperiments. One should expect a large yield gap and refrain from making any inferences about which hybrid Bt brinjal varietyis best in a region.The MST and LST were designed to answer the narrow question: how much does the EE-1 Bt transgene, by itself and allother things being equal (the ceteris paribis assumption), improve agronomic performance. This is not the relevant questionfor a farmer. A farmer is interested in whether hybrid Bt brinjal will “improve” things compared to what the farmer ispresently doing. For farmers, all things are not equal, and the concern is a comparison of brinjal varieties (often under unequalconditions), not merely the effect of the transgene. The narrow framing of the MST and LST limits the broader applicability ofthese data to problems of interest to the farmer or the Indian government.Finding 26. Insecticide use might decline in large-scale commercial Bt brinjal production systems by an average of6.5 applications. However, other factors may modulate this substantially, and new secondary pests will result in moreinsecticide use. It is not possible to estimate how insecticide use might change if Bt brinjal were used by small-scaleresource-poor farmers.Another expected advantage of Bt brinjal is a reduction in insecticide use. A reduction in the need for insecticide
Socioeconomic Analysis 53applications on brinjal would be welcomed by many farmers. The vastFigure 6. Number of insecticide applicationsmajority of Indian farmers recognise that insecticides have adverse effectseliminated by Bt brinjal compared to the non-Bton their personal health and the health of their families (Alam et al. control based on the large-scale trials (Supplemental2006, Barel et al. 2006).Materials).Brinjal farmers typically overuse insecticides (see Context and Needsection above). This is true for both large-scale commercial farmers andsmall-scale resource-poor farmers. Small-scale resource-poor farmersprobably apply insecticides much more frequently than large-scalecommercial farmers.Although EC-II and the Dossier imply that Bt brinjal will addressthe overuse of insecticides, the LST experiments are designed todetermine how much Bt brinjal can reduce insecticide use comparedto optimal use of insecticides to control BFSB. Optimal control isbased on applying insecticides when BFSB damage exceeds some threshold. Threshold-based application of insecticides is afundamental cornerstone of Integrated Pest Management (IPM).The results for the 11 sites and two years of LST experiments are shown in Fig. 6. At one site, two of the Bt brinjal varietieseliminated a whopping 16 applications of insecticides (2.4% of observations). However, in 6.4% of the observations Bt brinjaldid not eliminate any applications of insecticides. The variation is quite large (Fig. 6), and it may be a bimodal distribution,with some Bt brinjal varieties in some sites in some years eliminating >10 insecticide applications and another group eliminating
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Table of Contents 1Bt Brinjal Event
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Table of Contents iBt Brinjal:The s
Page 5 and 6: Summary and Conclusion 1Summary an
Page 7 and 8: Summary and Conclusion 3The EE-1 t
Page 9 and 10: Summary and Conclusion 5Event EE-1
Page 11 and 12: Summary and Conclusion 7Conclusion
Page 13 and 14: Context and Need 9standards for ER
Page 15 and 16: Context and Need 11and seek to incr
Page 17 and 18: Context and Need 13the reported yie
Page 19 and 20: Characterisation of Transgene 15Cha
Page 21 and 22: Characterisation of Transgene 17wor
Page 23 and 24: Characterisation of Transgene 19In
Page 25 and 26: Characterisation of Transgene 21Sci
Page 27 and 28: Environmental Risk Assessment 23Gen
Page 29: Environmental Risk Assessment 25thi
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Bt Brinjal The scope and adequacy of the GEAC environmental risk assessment

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