Journal Articles

There are hundreds of papers on eggplant and Bt crops. We provide a few selected articles in the areas of eggplant, environmental effects of Bt crops, and socio-economic impact of Bt crops.

Environmental effects of Bt plants

Field Performance of Bt Eggplants (Solanum melongena L.) in the Philippines: Cry1Ac Expression and Control of the Eggplant Fruit and Shoot Borer (Leucinodes orbonalis Guenée)

Plants expressing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling insect pests in maize and cotton globally. However, there are few Bt vegetable crops. Eggplant (Solanum melongena) is a popular vegetable grown throughout Asia that is heavily treated with insecticides to control the eggplant fruit and shoot borer, Leucinodes orbonalis (EFSB). Herein we provide the first publicly available data on field performance in Asia of eggplant engineered to produce the Cry1Ac protein. Replicated field trials with five Bt eggplant open-pollinated (OP) lines from transformation event EE-1 and their non-Bt comparators were conducted over three cropping seasons in the Philippines from 2010–2012. Field trials documented levels of Cry1Ac protein expressed in plants and evaluated their efficacy against the primary target pest, EFSB. Cry1Ac concentrations ranged from 0.75–24.7 ppm dry weight with the highest in the terminal leaves (or shoots) and the lowest in the roots. Cry1Ac levels significantly increased from the vegetative to the reproductive stage. Bt eggplant lines demonstrated excellent control of EFSB. Pairwise analysis of means detected highly significant differences between Bt eggplant lines and their non-Bt comparators for all field efficacy parameters tested. Bt eggplant lines demonstrated high levels of control of EFSB shoot damage (98.6–100%) and fruit damage (98.1–99.7%) and reduced EFSB larval infestation (95.8–99.3%) under the most severe pest pressure during trial 2. Moths that emerged from larvae collected from Bt plants in the field and reared in their Bt eggplant hosts did not produce viable eggs or offspring. These results demonstrate that Bt eggplant lines containing Cry1Ac event EE-1 provide outstanding control of EFSB and can dramatically reduce the need for conventional insecticides.

PLOS, 2016
Desiree M. Hautea, Lourdes D. Taylo, Anna Pauleen L. Masanga, Maria Luz J. Sison, Josefina O. Narciso, Reynaldo B. Quilloy, Randy A. Hautea, Frank A. Shotkoski, Anthony M. Shelton

Assessing Potential Impact of Bt Eggplants on Non-Target Arthropods in the Philippines

Studies on potential adverse effects of genetically engineered crops are part of an environmental risk assessment that is required prior to the commercial release of these crops. Of particular concern are non-target organisms (NTOs) that provide important ecosystem services. Here, we report on studies conducted in the Philippines over three cropping seasons with Bt eggplants expressing Cry1Ac for control of the eggplant fruit and shoot borer (EFSB), Leucinodes orbonalis, to examine potential effects on field abundance, community composition, structure and biodiversity of NTO’s, particularly non-target arthropod (NTA) communities. We document that many arthropod taxa are associated with Bt eggplants and their non-Bt comparators and that the number of taxa and their densities varied within season and across trials. However, we found few significant differences in seasonal mean densities of arthropod taxa between Bt and non-Bt eggplants. As expected, a lower abundance of lepidopteran pests was detected in Bt eggplants. Higher abundance of a few non-target herbivores was detected in non-Bt eggplants as were a few non-target beneficials that might control them. Principal Response Curve (PRC) analyses showed no statistically significant impact of Bt eggplants on overall arthropod communities through time in any season. Furthermore, we found no significant adverse impacts of Bt eggplants on species abundance, diversity and community dynamics, particularly for beneficial NTAs. These results support our previous studies documenting that Bt eggplants can effectively and selectively control the main pest of eggplant in Asia, the EFSB. The present study adds that it can do so without adverse effects on NTAs. Thus, Bt eggplants can be a foundational component for controlling EFSB in an Integrated Pest Management (IPM) program and dramatically reduce dependence on conventional insecticides.

PLOS, 2016
Mario V. Navasero, Randolph N. Candano, Desiree M. Hautea, Randy A. Hautea, Frank A. Shotkoski, Anthony M. Shelton

Field performance of Bt transgenic crops: A review

Genetically modified crops have been wildly cultivated in all over the world, since the commercialization of Bacillus thuringiensis (Bt) transgenic cotton in 1996. Some review papers have been summarized the benefit from the Bt transgenic crops and its ecological effects, but fewer of them focused on the agronomic and physiological performance comparison between Bt-transgenic crops with their non-Bt transgenic counterparts. Here, this review summarizes the researches on the field performance of Bt transgenic crops relative to their non-Bt counterparts, by focusing on differences in agronomic traits and Bt protein content, and the effect of abiotic stresses on the performance of Bt transgenic crops. Furthermore, the authors have discussed the physiological mechanisms underlying the variation of Bt protein content at different growth stages, or due to various environmental factors. In the end, crop management practices for maintaining stable Bt protein content and efficient control of pests were discussed.

Australian Journal of Crop Science, 2014
Wang, Fei; Peng, Shaobing; Cui, Kehui; Nie, Lixiao; Huang, Jianliang

Key global environmental impacts of genetically modified (GM) crop use 1996–2012

Against the background of increasing awareness and appreciation of issues such as global warming and the impact of mankind’s activities such as agriculture on the global environment, this paper updates previous assessments of some key environmental impacts that crop biotechnology has had on global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops. The adoption of the technology has reduced pesticide spraying by 503 million kg (-8.8%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator the Environmental Impact Quotient [EIQ]) by 18.7%. The technology has also facilitated a significant reduction in the release of greenhouse gas emissions from this cropping area, which, in 2012, was equivalent to removing 11.88 million cars from the roads.

GM Crops & Food: Biotechnology in Agriculture and the Food Chain, 2014
Peter Barfoot and Graham Brookes

No effects of Bacillus thuringiensis maize on nontarget organisms in the field in southern Europe: a meta-analysis of 26 arthropod taxa

Maize with the insecticidal properties of the entomopathogenic bacterium Bacillus thuringiensis Berliner, known as Bt maize, has been sown in Europe since 1998. For several years, EU and Spanish regulations have required laboratory and field trials to assess risks of genetically modified crops for nontarget organisms prior to their authorization. Thirteen field trials were conducted in Spain to measure the effects of Bt maize on a broad range of arthropod taxa; no effects were found in accordance with most literature records. However, statistical analyses of single trials rarely have the statistical power to detect low effect sizes if they do not have a sufficient sample size. When sample size is low, meta-analysis may improve statistical power by combining several trials and assuming a common measure of effect size. Here we perform a meta-analysis of the results of 13 independent field trials conducted in Spain in which effects of single or stacked Bt traits on several arthropod taxa were measured with no significant results. Since the taxa included in each single trial were not the same for all trials, for the meta-analysis we selected only those taxa recorded in a minimum of six trials, resulting finally in 7, 7, and 12 taxa analyzed in visual counts, pitfall traps and yellow sticky traps, respectively. In comparison with single trial analysis, meta-analysis dramatically increased the detectability of treatment effects for most of the taxa regardless of the sampling technique; of the 26 taxa analyzed, only three showed poorer detectability in the meta-analysis than the best recorded in the 13 single trials. This finding reinforces the conclusion that Bt maize has no effect on the most common herbivore, predatory and parasitoid arthropods found in the maize ecosystems of southern Europe.

Transgenic Research, 2014
C. Comas, B. Lumbierres, X. Pons, R. Albajes

Insecticide Residues in Eggplant Fruits, Soil, and Water in the Largest Eggplant-Producing Area in the Philippines

This study looked into the insecticide residues in eggplant, soil, and water samples in the largest eggplant-producing community in the Philippines as well as to analyze the fate of insecticides. The study area consisted of eggplant farms in a community in the largest eggplant producer in the Philippines. A total of 20 of the environmental samples were taken from the farms and analyzed using gas chromatography. The samples were distributed spatially over a mean distance of 451 m (s.d. = 20.2 m). For eggplant pesticide application, the mean spraying time of the farmers was 1.4 (sdv = 0.53) h/day, 4.13 (sdv = 1.9) days/week, 3.79 (sdv = 0.22) weeks/month, and 1 year/cropping season. Forty percent of the farm samples of eggplants had positive reading of insecticides cypermethrin and chlorpyrifos between 0.02 and 0.03 mg/kg. There was no positive reading for the 20 water samples. There was only one positive reading of chlorpyrifos in one farm out of 20 soil samples at 0.03 mg/kg. Although Prevathon and Malathion were used by all the farms for eggplant pesticide application, the liter-years of exposure to pesticide was very low for both (0.06, 0.56). Although Brodan and Magnum were not prevalently used, they had the highest liter-years of exposure to pesticide at 4.73 for chlorpyrifos, and 6.09 for cypermethrin. The amount and duration of use of insecticide is important in the determination of its persistence in vegetables and in the environment. In this study, Brodan was the largest and longest used insecticide for eggplants which explains why there was reading for both cypermethrin and chlorpyrifos in the eggplants, but none for Malathion and chlorantraniliprole. The presence of insecticide in water, soil, and plants is also based on its environmental fate. Pesticide regulation and pesticide residue monitoring have been pursued to varying degrees of success in the Philippines, but implementation is considered inadequate. The study also suggests for better implementation of pesticide regulation.

Water, Air, & Soil Pollution, 2011
Jinky Leilanie Lu

A Review of the Environmental Safety of the Cry1Ab Protein

This document provides a comprehensive review of information and data relevant to the environmental risk assessment of Cry1Ab and presents a summary statement about the environmental safety of this protein. All sources of information reviewed herein are publically available and include: dossiers presented to regulatory authorities; decision summaries prepared by regulatory authorities; peer reviewed literature; and product summaries prepared by product developers.  Environmental risk assessments related to the introduction of genetically engineered (GE) plants are conducted on a case-by-case basis taking into account the biology of the plant, the nature of the transgene and the protein it produces, the phenotype conferred by the transgene as well as the intended use of the plant and the environment where it will be introduced (i.e., the receiving environment). These assessments are comparative by necessity, and typically involve comparisons to an untransformed parent line or closely related isoline (CBD 2000a, 2000b, NRC 1989, OECD 1992, EFSA 2006, Codex 2003a, 2003b). The point of these comparisons is to identify potential risks the GE plant might present beyond what is already accepted for like plants in the environment. Any identified risks can then be assessed for their potential consequence. Regulatory approvals for environmental release of GE plants expressing Cry1Ab have been issued in 9 countries as well as the European Union. This includes six transformation events, approved in 17 lines, many of which contain additional GE traits.  

Center for Environmental Risk Assessment, ILSI Research Foundation, 2011

Guidance On the Environmental Risk Assessment of Genetically Modified Plants

This document provides guidance for the environmental risk assessment (ERA) of genetically modified (GM) plants submitted within the framework of Regulation (EC) No. 1829/2003 on GM food and feed or under Directive 2001/18/EC on the deliberate release into the environment of genetically modified organisms (GMOs). This document provides guidance for assessing potential effects of GM plants on the environment and the rationales for the data requirements for a comprehensive ERA of GM plants. The ERA should be carried out on a case-by-case basis, following a step-by-step assessment approach. This document describes the six steps for the ERA of GM plants, as indicated in Directive 2001/18/EC, starting with (1) problem formulation including hazard identification; (2) hazard characterisation; (3) exposure characterisation; (4) risk characterisation; (5) risk management strategies; and (6) an overall risk evaluation. The scientific Panel on Genetically Modified Organisms (of the European Food Safety Authority (EFSA GMO Panel) considers seven specific areas of concern to be addressed by applicants and risk assessors during the ERA (1) persistence and invasiveness of the GM plant , or its compatible relatives, including plant-to-plant gene transfer ; (2) plant-to-micro-organism gene transfer; (3) interaction of the GM plant with target organisms and (4) interaction of the GM plant with non-target organisms, including criteria for selection of appropriate species and relevant functional groups for risk assessment; (5) impact of the specific cultivation, management and harvesting techniques; including consideration of the production systems and the receiving environment(s); (6) effects on biogeochemical processes; and (7) effects on human and animal health. Each specific area of concern is considered in a structured and systematic way following the above-mentioned steps (1 to 6). In addition, the guidance document is supplemented with several general cross-cutting considerations (e.g. choice of comparator, receiving environment(s), general statistical principles, long-term effects) that need to be considered in the ERA.

European Food Safety Authority, 2010
Bartsch, Detlef et al.

Impacts of Bt crops on non-target invertebrates and insecticide use patterns

The ubiquitous nature of Bacillus thuringiensis (Bt), a Gram-positive bacterium capable of producing crystal proteins with insecticidal activity during sporulation, is now being mirrored in major crops plants that have been engineered through recombinant DNA to carry genes responsible for producing these crystal proteins and providing host plant resistance to major lepidopteran and coleopteran pests. In 2007, the 11th year of commercial production, Bt maize and Bt cotton were commercially produced on a total of 42 million hectares in 20 countries. Assessment of environmental safety has been and continues to be a key element of transgenic crop technology. This review focuses on two environmental elements, effects on non-target invertebrates and changes in insecticide use patterns since the adoption of Bt maize and cotton. Meta-analyses of the extant literature on invertebrate non-target effects reveals that the pattern and extent of impact varies in relation to taxonomy, ecological or anthropomorphic guild, route of exposure and the non- Bt control against which effects are gauged. Hazards identified in the laboratory may not always manifest in the field and the minor negative effects of Bt crops demonstrated in the field pale in comparison with alternative pest suppression measures based on insecticides. The efficacy of Bt maize and cotton against major pest species has been associated with an estimated 136.6 million kg global reduction in insecticide active ingredient used between 1996 and 2006 (29.9% reduction). Benefits vary by country and region and are heavily weighted towards cotton production, which has historically been one of the largest users of insecticides in the world.  

CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 2009
Steven E. Naranjo

Eggplant and Bt eggplant


The baseline suscepitbility of eggplant fruit and shott borer (Leucinodes orbonalis) populations in the Philippines to a Bacillus thuringiensis Cry1Ac protein was evaluated using a diet-overlay bioassay. Infested fruits with larvae were collected from none eggplant growing provinces in the Philippines during the 2012-2013 crop growing seasons. L. orbonalis  larvae were reared to adults on semi-synthetic diet, allowed to mate in the laboratory and produce eggs. The neonate larvae, from eggs of the field collected parents, were3 exposed to eith concentrations of Cry1Ac along with an untreated control and then assessed for mortality. The results showed that all L. orbonalis populations tested were susceptible to the Cry1Ac protein obtained from a bio insecticide that was used in the assay. Probit analyses of 35 bioassays of EFSB larvae collected from nine provinces showed that the median lethal concentrations ranged from 0.45 to 2.07 ng/cm while LC values ranged from 65.10 to 1501.00 ng/cm. Interpopulation variation in susceptibility was 4.6-fold and 23-fold at the LC and LC values, respectively. Linear Mixed Model and pairwise mean comparison analysis allowed pooling of the 35 bioassays data into four (4) groups. Effects of season and province for lethel concentrations and the slope for each group were insignificant. The median lethal concentrations ranged from 0.88 to 1.54 ng/cm and the LC values ranged from 119/23-470.73 ng/cm which represented a <2-fold and 4-fold variation in suscepibility, respectively. The results obtained in this study will be continued to generate more reliable estimates of the LC values which can be considered for develolpment of diagnostic concentrations in resistance monitoring.

The Philippines Entomologist, 2016
Lourdes D.taylo, Joseph C. Banasihan, Desiree Hautea, Srinivas Parimi

Biology and Management of Eggplant Fruit and Shoot Borer, Leucinodes orbonalis Guenee (Lepidoptera: Pyralidae)

Eggplant (Solanum melongena Linnaeus) is one of the most economically important vegetable of tropics having hot-wet climate. The key pest, eggplant fruit and shoot borer, Leucinodes orbonalis Guenee found to be most destructive and first ranked threat especially in South Asia, hence become hot issue for research in this region. It inflicts sizeable damage up to 80 percent in terms of fruit and content of vitamin-C. This situation refrained the farmers growing eggplant, hence relevant literature were gleaned and overviews regarding biology and management of borer with supportive facts and figure for safe and healthy eggplant production. As integrated approaches of pest management have been gaining popularity nowadays, this article outlines all the components of IPM including use of resistant varieties, sex pheromones, cultural methods, physical and mechanical barriers, bio-pesticides and bio-control agents, botanical and chemical means of management including basic biological parameters associated with management.

International Journal of Applied Sciences and Biotechnology, 2014
Ram Prasad Mainali

Socioeconomic Impacts of Bt Eggplant

In 2006-2009, the author conducted a series of ex-ante impact assessments of Bt eggplant adoption to evaluate potential benefits in terms of improving farmers’ and consumers’ welfare, improving the environment, alleviating poverty of eggplant farmers, and improving nutritional status of consumers.  Results of these studies showed big potential of the technology once released and adopted by farmers. In the absence of information on actual field plantings of Bt eggplant, these studies used information on the potential yield levels, benefits, and costs elicited from farmers, scientists and industry experts. This present study provides a thorough socioeconomic analysis of the eggplant production environment where multi-location field trials of Bt eggplant technology were conducted, including the socioeconomic profile of eggplant farmers and farms within the field trial sites. It quantifies the  benefits from  Bt eggplant technology based on results obtained from multi- location field trials, and analyzes its performance relative to non- Bt eggplant  in terms of yields, cost efficiency, net profitability, and other economic  parameters. It provides information to support the commercialization of Bt eggplant. It also details the knowledge, awareness, and perception (KAP) of farmers in Pangasinan and Camarines Sur where the field trials were conducted.  The conduct of field trials of the eggplant fruit and shoot borer (EFSB)- resistant ( Bt ) eggplant in Luzon was approved by the Bureau of Plant Industry  through biosafety permits issued on 15 March 2010. The field trials aimed to generate information on the efficacy, yield, and horticultural performance of promising EFSB-resistant transgenic eggplant lines (Bt eggplant) containing MAHYCO event EE-1 into an open-pollinated variety (OPV). It also aimed to generate local data on non-target arthropods in support of biosafety regulatory approval for propagation and Fertilizer and Pesticide Authority (FPA) registration. Two of the approved trial sites in Luzon include Sta. Maria, Pangasinan and Central Bicol State University for Agriculture (CBSUA) in Pili,  Camarines Sur.  

Socioeconomic Impacts of Bt Eggplant: Ex-ante Case Studies in the Philippines, 2014
SR Francisco

Costs and benefits of UPLB Bt Eggplant with Resistance to Fruit and Shoot Borer in the Philippines

Eggplant, Solanum melongena L., is one of the most economically important vegetable crops in the Philippines currently valued at PhP3.44 billion (BAS, 2008). Production generally increased from 1990 to 2007, same with area except in 1998 (Figure 1). Yield followed a pattern similar to production until 1999 when it barely moved. Nevertheless, eggplant accounted for an average  of 29 percent of the total quantity of vegetables produced, equivalent to an  average of 185,153 metric tons from 2000-2007 (BAS, 2008). As with other vegetables, eggplant prices are highly seasonal in the Philippines – low during the summer months of March to May and high during the colder months of November to January. This price pattern reflects the volume of product available in the market. At constant prices, the value of eggplant production remained to be the highest among vegetables in the Philippines from 2000-2007. Within the same period, the top eggplant producing provinces were Pangasinan, Quezon, and Isabela which gave an average combined production of 93,095 metric tons. Pangasinan and Quezon accounted for nearly 50 percent of total eggplant production in the Philippines.  

Projected Impacts of Agricultural Biotechnologies for Fruits and Vegetables in the Philippines and Indonesia, 2009
S.R. Francisco

Is genetically engineered technology a good alternative to pesticide use? The case of GE eggplant in India

Are pesticides used efficiently in eggplant cultivation? Is Genetically Engineered (GE) eggplant a good alternative to pesticide use? Building on the literature on damage control specification for production functions, we estimated the pesticide productivity for eggplant, using data from a farm‐level survey conducted in Maharashtra, India. Even though the intensity of pesticide use by Open Pollinated Variety (OPV) growers is less relative to hybrid growers, the average use of pesticides is substantially greater than the estimated optimum use levels. We then used Bt trial plot data to estimate the potential benefits that Bt technology might provide in terms of reduction in pesticide application. If the adoption of GE eggplant reduces the pesticide use by 52%, as is reported from the field trials of GE eggplant, that will result in a saving of Rs. 6844/acre for hybrid growers and Rs. 2784/acre for OPV growers. Results from our study suggest that GE technology provides a good alternative to pesticide use for farmers in developing countries such as India.

International Journal of Biotechnology, 2008
Deepthi Kolady and William Lesser

Economic and Environmental Benefits and Costs of Transgenic Crops: Ex-Ante Assessment

Agricultural Biotechnology Support Project II, 2007
C.Ramasamy, K.N. Selvaraj, George W. Norton, and K.Vijayaraghavan (Eds.)

Economic and social value of Bt plants

A Meta-Analysis of the Impacts of Genetically Modified Crops

Despite the rapid adoption of genetically modified (GM) crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion.

PLOS One, 2014
Klümper W, Qaim M

Economic, Ecological, Food Safety, and Social Consequences of the Deployment of Bt Transgenic Plants

Transgenic plants expressing insecticidal proteins from the bacterium, Bacillus thuringiensis (Bt), are revolutionizing agriculture. Bt, which had limited use as a foliar insecticide, has become a major insecticide because genes that produce Bt toxins have been engineered into major crops grown on 11.4 million ha worldwide in 2000. Based on the data collected to date, generally these crops have shown positive economic benefits to growers and reduced the use of other insecticides. The potential ecological and human health consequences of Bt plants, including effects on nontarget organisms, food safety, and the development of resistant insect populations, are being compared for Bt plants and alternative insect management strategies. Scientists do not have full knowledge of the risks and benefits of any insect management strategies. Bt plants were deployed with the expectation that the risks would be lower than current or alternative technologies and that the benefits would be greater. Based on the data to date, these expectations seem valid.

Annual Review of Entomology, 2002
A. M. Shelton, J.-Z. Zhao, and R. T. Roush