Post-Industrial Agriculture: Competing Proposals for the Transformation of Agiculture

For many years, scientists have been sounding the alarm that the global ecosystem is in a precarious state and possibly on the verge of abrupt changes due to anthropogenic pressures

Simulating evolutionary responses of an introgressed insect resistance trait for ecological effect assessment of transgene flow: a model for supporting informed decisionmaking in environmental risk assessment

Predicting outcomes of transgene flow from arable crops requires a system perspective that considers ecological and evolutionary processes within a landscape context. In Europe, the arable weed Raphanus raphanistrum is a potential hybridization partner of oilseed rape, and the two species are ecologically linked through the common herbivores Meligethes spp. Observations in Switzerland show that high densities of Meligethes beetles maintained by oilseed rape crops can lead to considerable damage on R. raphanistrum. We asked how increased insect resistance in R. raphanistrum – as might be acquired through introgression from transgenic oilseed rape – would affect seed production under natural herbivore pressure. In simulation experiments, plants protected against Meligethes beetles produced about twice as many seeds as unprotected plants. All stages in the development of reproductive structures from buds to pods were negatively affected by the herbivore, with the transition from buds to flowers being the most vulnerable. We conclude that resistance to Meligethes beetles could confer a considerable selective advantage upon R. raphanistrum in regions where oilseed rape is widely grown

Main challenges and key features of indicator-based agroecological assessment frameworks in the context of international cooperation

Agroecology increasingly gains importance in the discussion about sustainable food systems. To facilitate the transition from conventional farming to agroecological farming, adequate methods and concepts to measure and assess impact and productivity of agroecological farming systems (AFSs) are needed, which consider their multifunctionality and other specific characteristics, here called agroecological sustainability assessment frameworks and tools (ASAFTs). In the past years, many agricultural sustainability assessment tools and frameworks were developed but their suitability and applicability to AFSs was not investigated. To close this knowledge gap, we aimed at identifying, reviewing, and discussing published ASAFTs in the context of international cooperation, providing an overview of the current challenges, needs, and requirements in assessing AFSs at the farm level with the means of indicators. Desktop and scientific database research was conducted to identify and discuss published indicator-based ASAFTs at the farm level. The analysis was based on the following four framework elements that the authors considered to be essential for ASAFTs: (1) the adaptability to local conditions all over the world, (2) the involvement of farmers in the development process, (3) the consideration of the multiple functions of an agroecosystem in the definition and measurement of its productivity, and (4) the accounting for interactions between multiple agroecosystem functions and their measurement. Only a few analyzed assessment frameworks at least partly consider these essential elements and were designed specifically for AFSs. However, our study also showed that these frameworks were (1) restricted in their geographical application scope, (2) quite heterogeneous and barely comparable, and (3) based on productivity indicators that do not fully capture the multiple functions of AFSs. Therefore, we identified the need for the development of appropriate agroecological productivity indicators and common standard or reference frameworks for assessing AFSs, which will be crucial for upscaling agroecology

Identifying indicator species for post-release monitoring of genetically modified, herbicide resistant crops

In Europe, regulations for release and placing-on-the-market of genetically modified (GM) crops require post-release monitoring of their impact on the environment. Monitoring potential adverse effects of GM crops includes direct effects as well as indirect effects, e.g. GM crop specific changes in land and pest management. Currently, there is a gap in the pre-release risk assessments conducted for regulatory approval of GM herbicide resistant (HR) crops. Since the relevant non-selective herbicides have been registered many years ago, in current dossiers requesting regulatory approval of GM HR crops, the environmental impacts of the corresponding non-selective herbicides are either entirely omitted or the applicant simply refers to the eco-toxicological safety assessments conducted for its original pesticide approval that do not address environmental issues arising in conjunction with the cultivation of GM HR crops. Since the ‘Farm-scale Evaluations', it is clear that consequences for farmland biodiversity can be expected. The objective of this project was to identify relevant indicator species for the long-term impact of GM HR maize cultivation and the application of their corresponding non-selective herbicides, glyphosate and glufosinate. In this article, we describe the outcome of a modified Event Tree Analysis, essentially a funnel-like procedure allowing to reduce the large number of potentially affected non-target species to those with greatest ecological relevance and highest risk to be adversely affected based on a number of ecological criteria. This procedure allowed us to identify a total of 21 weed-Lepidoptera associations that we proposed for post release monitoring of GM HR maize in German

Field decomposition of transgenic Bt maize residue and the impact on non-target soil invertebrates

Genetically modified Bacillus thuringiensis Berliner (Bt) maize (Zea mays L.) expressing Cry toxins against various target pests is now grown on more than 16 million hectares worldwide, but its potential effects on the soil ecosystem need to be further investigated. In an 8-month field study, we investigated the effects of Bt maize expressing the Cry1Ab protein on both the soil community and maize residue decomposition. We used litterbags with three different mesh sizes (20, 125, and 5,000μm) to investigate potential effects of different soil organism groups on the decomposition processes. Litterbags were incorporated into the soil in fall into a field that had previously been planted with non-Bt maize and subsamples were removed monthly. The dry weight of the remaining residue was measured for all bags. Bt and non-Bt maize decomposed similarly in large mesh bags, which allowed the whole soil organism community to enter and interact with each other. In contrast, Bt maize decomposed significantly faster than non-Bt maize at some sample dates in winter in bags with small and medium mesh sizes. At the end of the experiment in late spring, however, there was no significant difference in the amount of maize plant residues remaining for any of these three mesh sizes. Additionally, soil organisms from bags with the largest mesh size were identified. The most frequent taxa extracted were collembolans (Isotomidae, Tullbergiidae, Entomobryidae), mites (Gamasina, Oribatida), and annelids (Enchytraeidae). Three of these taxa were extracted in higher numbers from non-Bt than Bt residue (Tullbergiidae, Gamasina, Enchytraeidae), while there was no difference in the number of individuals extracted for the remaining three taxa. Our results do not show major changes in the decomposition of Bt maize residue and in the composition of the soil organism community. However, further studies are needed that assess the impact of the continuous release of Cry1Ab via root exudates and plant biomass on the soil ecosyste

Tritrophic Interactions of Transgenic Bacillus thuringiensis Corn, Anaphothrips obscurus (Thysanoptera: Thripidae), and the Predator Orius majusculus (Heteroptera: Anthocoridae)

Laboratory feeding experiments using transgenic Bacillus thuringiensis variety kurstaki (Berliner) corn plants were carried out to study the effects of B. thuringiensis-fed herbivorous prey on the predator Orius majusculus (Reuter). Host plants were a transgenic B. thuringiensis-expressing (Cry1Ab) corn hybrid and the corresponding untransformed isogenic B. thuringiensis-free corn hybrid. The herbivorous prey species used in the experiment was Anaphothrips obscurus (Müller), a thysanopteran pest of corn, not sensitive to Cry1Ab toxin. The objectives were to quantify the effects of B. thuringiensis-fed prey on the development and mortality of immature O. majusculus. There was no significant difference in total mean mortality from hatch to adult eclosion between O. majusculus nymphs reared on B. thuringiensis-fed or B. thuringiensis-free prey. Similarly, no significant differences in total developmental time of O. majusculus was detected when reared on the two different prey types. Overall mortality was low, confirming that the methodology used was appropriate. We propose this approach as an efficient standardized preregistrational testing for side effects of transgenic plants on small predators such as Orius sp

Environmental risk assessment of genetically modified plants - concepts and controversies

Background and purpose: In Europe, the EU Directive 2001/18/EC lays out the main provisions of environmental risk assessment (ERA) of genetically modified (GM) organisms that are interpreted very differently by different stakeholders. The purpose of this paper is to: (a) describe the current implementation of ERA of GM plants in the EU and its scientific shortcomings, (b) present an improved ERA concept through the integration of a previously developed selection procedure for identification of non-target testing organisms into the ERA framework as laid out in the EU Directive 2001/18/EC and its supplement material (Commission Decision 2002/623/EC), (c) describe the activities to be carried out in each component of the ERA and (d) propose a hierarchical testing scheme. Lastly, we illustrate the outcomes for three different crop case examples. Main features: Implementation of the current ERA concept of GM crops in the EU is based on an interpretation of the EU regulations that focuses almost exclusively on the isolated bacteria-produced novel proteins with little consideration of the whole plant. Therefore, testing procedures for the effect assessment of GM plants on non-target organisms largely follow the ecotoxicological testing strategy developed for pesticides. This presumes that any potential adverse effect of the whole GM plant and the plant-produced novel compound can be extrapolated from testing of the isolated bacteriaproduced novel compound or can be detected in agronomic field trials. This has led to persisting scientific criticism. Results: Based on the EU ERA framework, we present an improved ERA concept that is system oriented with the GM plant at the centre and integrates a procedure for selection of testing organisms that do occur in the receiving environment. We also propose a hierarchical testing scheme from laboratory studies to field trials and we illustrate the outcomes for three different crop case examples. Conclusions and recommendations: Our proposed concept can alleviate a number of deficits identified in the current approach to ERA of GM plants. It allows the ERA to be tailored to the GM plant case and the receiving environment

Effects of Activated Bt Transgene Products (Cry1Ab, Cry3Bb) on Immature Stages of the Ladybird Adalia bipunctata in Laboratory Ecotoxicity Testing

Insect-active Bacillus thuringiensis (Bt) proteins are expressed by several transgenic crop plants to control certain pests, but nontarget organisms such as ladybirds also can be exposed to these proteins in the field. We developed an improved ecotoxicity testing protocol and conducted feeding trials in a laboratory setting to test for possible adverse effects of different concentrations of microbially produced trypsin-activated Cry1Ab and Cry3Bb toxins on the coccinellid Adalia bipunctata. Larval/pupal mortality, development time, and overall body mass accumulation were recorded. Even at the lowest concentration (5 μg/ml), A. bipunctata larvae fed with the lepidopteran-active Cry1Ab toxin exhibited significantly higher mortality than the control group. In experiments with the coleopteran-active Cry3Bb, only a concentration of 25 μg/ml resulted in a marginally significantly higher mortality compared to the control. Both experiments revealed a slight decline in mortality at the highest concentration of 50 μg/ml, though this was statistically significant only in the Cry1Ab treatment. No differences were detected for development time and body mass of newly emerged adults. Dilutions of the expression vector pBD10—used as a control to exclude effects of the toxin production method—at concentrations between 10 and 100 μg/ml revealed no significant effects on either of the studied parameters. This suggests that the increased mortality of larvae in the toxin feeding trials was caused directly by the activated Bt toxins and raises questions regarding their commonly postulated specificity and their mode of action in A. bipunctata. Implications of the reported results for ladybird populations and their biological pest control functions in transgenic crop ecosystems are discusse

Ict4Agroecology - A Farmer Participatory Research Project In Tanzania

The role of technologies to support a transition to agroecological production systems is becoming increasingly important(e.g. digital or biotechnological technologies). Technologies are often assigned the role of a key driver of change wherethe proposed, mostly proprietary technologies shape the change process and require adaptation of the farmer and theproduction system to the technology in order to allow the technology to realize its maximum potential. We place the focuson the farmer and the agroecological production systems and retool digital technologies to support the farmers inrealizing the maximum potential of their agroecological production systems. Here, we present the current outcomes of theResearch and Advocacy on Agroecology program, coordinated by Swissaid Tanzania, and implemented by national andinternational partners, including Sustainable Agriculture Tanzania (SAT), Sokoine University of Agriculture (SUA) and theSwiss Federal Institute of Technology (ETH)

Toxicity of Bacillus thuringiensis CrylAb Toxin to the Predator Chrysoperla carnea (Neuroptera: Chrysopidae)

Laboratory feeding studies were carried out to determine the effects of the Bacillus thuringiensis (Berliner) CrylAb toxin on developmental time and mortality of Chrysoperla carnea (Stephens) larvae. A bioassay technique was developed that allowed for incorporation of the CrylAb toxin into a liquid diet that was then encapsulated within small paraffin spheres. Because only 2nd and 3rd instars can penetrate the surface of the paraffin spheres, 2 different methods were used to rear chrysopid larvae through the 1st instar. The 1st method used small foam cubes soaked in non-encapsulated, liquid diet (with or without CrylAb). The 2nd method used Ephestia kuehniella (Hübner) eggs as prey during the first instar (no CrylAb exposure). After reaching the 2nd instar, all larvae received encapsulated, artificial diet with or without CrylAb, respectively. When reared only on artificial diet containing CrylAb toxin, total immature mortality was significantly higher (57%) than in the respective untreated control (30%). Also, significantly more chrysopid larvae died (29%) that received CrylAb later during their larval development compared with the respective control (17%). Although mortality was consistently higher, no or only small differences in developmental times were observed between CrylAb-treated and untreated C. carnea larvae. C. carnea larvae required significantly more time to complete larval development when reared on artificial diet only than when reared first on E. kuehniella eggs followed by encapsulated artificial diet or on only E. kuehniella eggs, regardless of exposure to CrylAb. These results demonstrate that CrylAb is toxic to C. carnea at 100 μmg/ml of diet by using encapsulated artificial die