Dow AgroSciences LLC Research Articles

Synthesis and biological activity of analogs of the antifungal antibiotic UK-2A. II. Impact of modifications to the macrocycle benzyl position.

UK-2A is an antifungal antibiotic produced by Streptomyces sp. 517-02. Derivatization of its picolinamide OH to form the isobutyryl acetal led to the discovery of fenpicoxamid (InatreqTM active), which is currently under development as a fungicide by Dow AgroSciences LLC. This paper documents efforts to achieve additional efficacy enhancements through semi-synthetic modification of the benzyl substituent of the UK-2A macrocycle. Of 34 analogs prepared, the most active had mitochondrial electron transport IC50 values 1.5- to 3.7-fold higher than UK-2A (IC50 0.86 nM). The cyclohexyl analog (38, IC50 1.23 nM) was the most intrinsically active derivative, and inhibited in vitro growth of Zymoseptoria tritici (EC50 2.8ppb) and Leptosphaeria nodorum (EC50 6.2ppb) more strongly than UK-2A (EC50 5.3 and 11.3ppb for Z. tritici and L. nodorum, respectively). Heterocyclic ring systems and polar linker functionalities resulted in substantial activity loss. Several analogs (20, 22, 23, 24, 36 and 38) translated Z. tritici in vitro growth inhibition activity to in planta disease control more effectively than did UK-2A, with log D being a key factor in this regard. UK-2A is amenable to further modification at the benzyl position on the macrocycle, which provides opportunities for manipulation of physical properties while retaining strong intrinsic and antifungal activity. © 2019 Society of Chemical Industry.

Assessment of genetically modified maize 1507×NK603 for renewal of authorisation under Regulation (EC) No1829/2003 (application EFSA-GMO-RX-008).

Following the submission of application EFSA‐GMO‐RX‐008 under Regulation (EC) No 1829/2003 from Pioneer Hi‐Bred International, Inc. and Dow AgroSciences LLC, the Panel on Genetically Modified Organisms of the European Food Safety Authority was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the insect‐resistant, herbicide‐tolerant genetically modified maize 1507 × NK603, for food and feed uses, import and processing, excluding cultivation within the EU. The data received in the context of this renewal application contained a systematic search and evaluation of literature, updated bioinformatic analyses and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. In conclusion, under the assumption that the DNA sequence of the events in maize 1507 × NK603 considered for renewal are identical to the newly reported 1507 sequence and the NK603 sequence of the originally assessed two‐event stack maize, the GMO Panel concludes that there is no evidence in the renewal application EFSA‐GMO‐RX‐008 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize 1507 × NK603 (EFSA, 2006).

Scientific opinion on an application for renewal of authorisation for continued marketing of maize59122 and derived food and feed submitted under articles 11 and 23 of Regulation (EC) No1829/2003 by Pioneer Overseas Corporation and Dow AgroSciences LLC.

Following the submission of application EFSA‐GMO‐RX‐003 under Regulation (EC) No 1829/2003 from Pioneer Overseas Corporation and Dow AgroSciences LLC, the Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application of the insect‐resistant genetically modified maize 59122. The data received in the context of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatics analyses, and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in maize 59122 considered for renewal is identical to the corrected sequence of the originally assessed event, the GMO Panel concludes that no new hazards or modified exposure and no new scientific uncertainties were identified that would change the conclusions of the original risk assessment on maize 59122.

Efficacy of herbicidal ionic liquids and choline salt based on 2,4-D

Five quaternary ammonium salts with the 2,4-dichlorophenoxyacetate [2,4-D] anion were synthesized and their physicochemical properties and efficacy against weeds was investigated. The following cations were used in the synthesis: (2-hydroxyethyl)trimethylammonium [Choline], (2-chloroethyl)trimethylammonium [CC], cocotrimethylammonium [Arq], bis(2-hydroxyethyl)cocomethylammonium [Etq C] and bis(2-hydroxyethyl)methyloleylammonium [Etq O]. Among them, four compounds: [CC][2,4-D], [Arq][2,4-D], [Etq C][2,4-D] and [Etq O][2,4-D] were classified as herbicidal ionic liquids (HILs).Data from greenhouse studies showed similar or better efficacy of ionic liquids based on 2,4-D compared to commercial formulations of 2-ethylhexyl ester and dimethylammonium salt and also to choline salts which is recently marketed but in the mixture with glyphosate (Enlist Duo, Dow AgroSciences LLC). HILS with 2,4-D anion also showed excellent efficacy in field experiments. In this case, all tested HILs demonstrated several times higher efficacy compared to choline, dimethylammonium salts and 2-ethylhexyl ester.All the described results suggest that selection of an appropriate cation allows to control the physicochemical properties of studied herbicidal ionic liquids, which proved to have a significant impact on its biological activity.

Scientific opinion on an application by Dow AgroSciences LLC (EFSA-GMO-NL-2012-106) for the placing on the market of genetically modified herbicide-tolerant soybean DAS-44406-6 for food and feed uses, import and processing under Regulation (EC) No1829/2003.

Soybean DAS‐44406‐6 expresses 5‐enolpyruvyl‐shikimate‐3‐phosphate synthase (2mEPSPS), conferring tolerance to glyphosate‐based herbicides, aryloxyalkanoate dioxygenase (AAD‐12), conferring tolerance to 2,4‐dichlorophenoxyacetic acid (2,4‐D) and other related phenoxy herbicides, and phosphinothricin acetyl transferase (PAT), conferring tolerance to glufosinate ammonium‐based herbicides. The molecular characterisation data and bioinformatics analyses did not identify issues requiring assessment for food/feed safety. The agronomic and phenotypic characteristics revealed no relevant differences between soybean DAS‐44406‐6 and its conventional counterpart, except for pod count, seed count and yield. The compositional analysis identified no differences requiring further assessment, except for an increase (up to 31%) in lectin activity in soybean DAS‐44406‐6. Such increase is unlikely to raise additional concerns for food/feed safety and nutrition of soybean DAS‐44406‐6 as compared to its conventional counterpart and non‐GM reference varieties. There were no concerns regarding the potential toxicity and allergenicity of the three newly expressed proteins, and no evidence that the genetic modification might significantly change the overall allergenicity of soybean DAS‐44406‐6. Soybean DAS‐44406‐6 is as nutritious as its conventional counterpart and the non‐GM soybean reference varieties tested. There are no indications of an increased likelihood of establishment and spread of occasional feral soybean DAS‐44406‐6 plants, unless exposed to the intended herbicides. The likelihood of environmental effects from the accidental release of viable seeds from soybean DAS‐44406‐6 into the environment is therefore very low. The post‐market environmental monitoring plan and reporting intervals are in line with the intended uses of soybean DAS‐44406‐6. In conclusion, the GMO Panel considers that the information available for soybean DAS‐44406‐6 addresses the scientific comments raised by Member States and that soybean DAS‐44406‐6, as described in this application, is as safe as its conventional counterpart and non‐GM soybean reference varieties with respect to potential effects on human and animal health and the environment in the context of the scope of this application.

Scientific Opinion on an application by Dow AgroSciences LLC (EFSA-GMO-NL-2011-91) for the placing on the market of genetically modified herbicide-tolerant soybean DAS-68416-4 for food and feed uses, import and processing under Regulation (EC) No1829/2003.

Soybean DAS‐68416‐4 was developed by Agrobacterium tumefaciens‐mediated transformation to express the aryloxyalkanoate dioxygenase‐12 (AAD‐12) protein, conferring tolerance to 2,4‐dichlorophenoxyacetic acid (2,4‐D) and other related phenoxy herbicides, and the phosphinothricin acetyltransferase (PAT) protein, conferring tolerance to glufosinate ammonium‐based herbicides. The molecular characterisation data and bioinformatics analyses did not identify issues requiring further assessment for food/feed safety. The agronomic and phenotypic characteristics tested revealed no relevant differences between soybean DAS‐68416‐4 and its conventional counterpart, except for ‘days to 50% flowering’. The compositional analysis identified no differences requiring further assessment, except for an increase (up to 36%) in lectin activity in soybean DAS‐68416‐4. Such increase is unlikely to raise additional concerns for food/feed safety and nutrition for soybean DAS‐68416‐4 as compared to its conventional counterpart and the non‐GM reference varieties. There were no concerns regarding the potential toxicity and allergenicity of the two newly expressed proteins, and no evidence that the genetic modification might significantly change the overall allergenicity of soybean DAS‐68416‐4. Soybean DAS‐68416‐4 is as nutritious as its conventional counterpart and the non‐GM reference varieties. There are no indications of an increased likelihood of establishment and spread of occasional feral soybean DAS‐68416‐4 plants, unless these are exposed to the intended herbicides. The likelihood of environmental effects resulting from the accidental release of viable seeds from soybean DAS‐68416‐4 into the environment is therefore very low. The post‐market environmental monitoring plan and reporting intervals are in line with the intended uses of soybean DAS‐68416‐4. The GMO Panel concludes that the information available addresses the scientific comments of the Member States and that soybean DAS‐68416‐4, as described in this application, is as safe as its conventional counterpart and the tested non‐GM reference varieties with respect to potential effects on human and animal health and the environment in the context of the scope of this application.

Scientific opinion on an application for renewal of authorisation for continued marketing of maize1507 and derived food and feed submitted under Articles 11 and 23 of Regulation (EC) No1829/2003 by Pioneer Overseas Corporation and Dow AgroSciences LLC.

Following the submission of application EFSA‐GMO‐RX‐001 under Regulation (EC) No 1829/2003 from Pioneer Overseas Corporation and Dow Agrosciences LLC, the Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) was asked to deliver a scientific risk assessment on the data submitted in the frame of a renewal of authorisation application of the insect‐resistant and herbicide‐tolerant genetically modified (GM) maize 1507. The data package received in the frame of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, an updated bioinformatics analysis and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed this data package for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the frame of the original application. Under the assumption that the DNA sequence of the event in maize 1507 considered for renewal is identical to the corrected sequence of the originally assessed event, the GMO Panel concludes that no new hazards or modified exposure and no new scientific uncertainties were identified for the application for renewal that would change the conclusions of the original risk assessment on maize 1507 (EFSA, 2005b, 2009).

Scientific Opinion on an application by DOW AgroSciences LLC (EFSA‐GMO‐NL‐2010‐89) for placing on the market the genetically modified herbicide‐tolerant maize DAS‐40278‐9 for food and feed uses, import and processing under Regulation (EC) No 1829/2003

Maize DAS-40278-9 was developed by direct Whiskers-mediated transformation to express the aryloxyalkanoate dioxygenase-1 (AAD-1) protein, conferring tolerance to 2,4-dichlorophenoxyacetic acid (2,4-D) and aryloxyphenoxypropionate (AOPP) herbicides. The molecular characterisation of maize DAS-40278-9 did not raise safety issues. The agronomic, phenotypic and compositional characteristics of maize DAS-40278-9 tested under field conditions revealed no differences between maize DAS-40278-9 and its non-genetically modified (GM) comparator that would give rise to food and feed or environmental safety concerns. There were no concerns regarding the potential toxicity and allergenicity of the newly expressed protein AAD-1, and no evidence that the genetic modification might significantly change the overall allergenicity of maize DAS-40278-9. The nutritional characteristics of maize DAS-40278-9 are not expected to differ from those of non-GM maize varieties and no post-market monitoring of food/feed is considered necessary. Maize DAS-40278-9 is as nutritious as its non-GM comparator and other non-GM commercial varieties. There are no indications of an increased likelihood of establishment and spread of occasional feral maize DAS-40278-9 plants, unless these plants are exposed to the intended herbicides. However, this will not result in different environmental impacts compared to conventional maize. Considering the scope of the application, interactions with the biotic and abiotic environment were not considered an issue. Risks associated with the unlikely but theoretically possible horizontal gene transfer from maize DAS-40278-9 to bacteria were not identified. The post-market environmental monitoring plan and reporting intervals are in line with the scope of the application. In conclusion, the EFSA GMO Panel considers that the information available for maize DAS-40278-9 addresses the scientific comments raised by the Member States and that maize DAS-40278-9, as described in this application, is as safe as the non-GM comparator and non-GM maize reference varieties with respect to potential effects on human and animal health and the environment in the context of the scope of this application.

Outcome of a public consultation on the draft Guidance to develop specific protection goals options for environmental risk assessment at EFSA, in relation to biodiversity and ecosystem services

Outcome of a public consultation on the draft Guidance to develop specific protection goals options for environmental risk assessment at EFSA, in relation to biodiversity and ecosystem services

Scientific Opinion on an application by Dow Agrosciences LLC (EFSA‐GMO‐NL‐2009‐68) for placing on the market of cotton 281‐24‐236 × 3006‐210‐23 × MON 88913 for food and feed uses, import and processing under Regulation (EC) No 1829/2003

Scientific Opinion on an application by Dow Agrosciences LLC (EFSA‐GMO‐NL‐2009‐68) for placing on the market of cotton 281‐24‐236 × 3006‐210‐23 × MON 88913 for food and feed uses, import and processing under Regulation (EC) No 1829/2003

Scientific Opinion on an application by Dow Agrosciences LLC (EFSA-GMO-NL-2009-68) for placing on the market of cotton 281-24-236 3 3006-210-23 3 MON 88913 for food and feed uses, import and processing under Regulation (EC) No 1829/2003

The Panel on Genetically Modified Organisms of the European Food Safety Authority (GMO Panel) previously assessed the three single events combined to produce a three-event stack cotton 281-24-236 9 3006-210-23 9 MON 88913 and did not identify safety concerns. In this opinion, the GMO Panel assesses only the three-event stack cotton. No new data on the single events, leading to modification of the original conclusions on their safety, were identified. The combination of cotton events 281-24-236, 3006-210-23 and MON 88913 in the three-event stack cotton did not give rise to issues – based on the molecular, agronomic, phenotypic or compositional characteristics – regarding food and feed safety and nutrition. The combination of the newly expressed proteins in the threeevent stack cotton did not raise concerns for human and animal health. Considering the introduced traits and the outcome of the comparative analysis, the routes of exposure and limited exposure levels, the GMO Panel concludes that this three-event stack cotton would not raise safety concerns in case of accidental release of viable cottonseeds into the environment. The post-market environmental monitoring plans provided by the applicant are in line with the scope of the three-event stack cotton. No post-market monitoring of food/feed derived from the three-event stack cotton is considered necessary. The GMO Panel concludes that the three-event stack cotton is as safe and as nutritious as its conventional counterpart in the context of its scope.

Development of a Scalable Process for the Crop Protection Agent Isoclast

A scalable process to the insecticide Isoclast manufactured by Dow AgroSciences LLC is described. The process involves the de novo construction of a fully elaborated pyridine sulfide using enamine-mediated cyclization followed by two efficient and inexpensive oxidations to introduce the sulfoximine.

Claim Construction Cannot Save a Modified Gene Invention Claimed with a Scientifically Debatable Biological Mechanism: A Lesson from Bayer CropScience AG v. Dow AgroSciences LLC, 728 F.3d 1324 (Fed. Cir. 2013).

Bayer CropScience AG owns U.S. Patent No. 6,153,401, which claims a genetically modified plant that incorporates a tfdA gene.1 Because of the product of this gene, the plant can resist a weed herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D).2 The biological action associated with the tfdA gene is degradation of 2,4-D into 2,4-dichlorophenol (2,4-DCP) by an enzyme encoded by the tfdA gene.3 This enzyme was mistakenly known as a “monooxygenase” among the scientific community when Bayer was developing the invention.4

Control of Canada fleabane (<i>Conyza canadensis</i>) with glyphosate DMA/2,4-D choline applications in corn (<i>Zea mays</i>)

Glyphosate resistant (GR) Canada fleabane (horseweed) has quickly spread across southwestern Ontario and is a difficult weed to control in GR crops. Glyphosate dimethylamine (DMA)/2,4-D choline (Enlist Duo?TM Dow AgroSciences LLC), a new herbicide premix developed by Dow Agro Sciences, provides control of GR and other problematic weeds. The objective of this study was to compare single and sequential applications of glyphosate DMA/2,4-D choline for the control of GR Canada fleabane in GR corn. Three single applications of glyphosate (DMA)/2,4-D choline (1720 g·ae·ha-1) were evaluated: 1) preplant (PP) applied to Canada fleabane up to 10 cm diameter/height, 2) postplant 1 (POST 1) applied when Canada fleabane was up to 20 cm tall and 3) postplant 2 (POST 2) applied up to 30 cm tall Canada fleabane. Four sequential applications were also examined:1) PP followed by (fb) POST 1, 2) PP fb POST 2, 3) POST 1 fb POST 2 and 4) PP fb POST 1 fb POST 2. The single applications provided 69%-86% control of the GR Canada fleabane while the sequential applications increased control to 92%-100%. Three applications did not provide an increase in control over a sequential two-pass application at 8 weeks after the application (WAA). Results from this research indicate that a sequential 2-pass application of glyphosate DMA/2,4-D choline provided acceptable control of GR Canada fleabane in corn.

Sensitivity of hypogean and epigean freshwater copepods to agricultural pollutants

Widespread pollution from agriculture is one of the major causes of the poor freshwater quality currently observed across Europe. Several studies have addressed the direct impact of agricultural pollutants on freshwater biota by means of laboratory bioassays; however, as far as copepod crustaceans are concerned, the ecotoxicological research is scarce for freshwater species and almost nonexistent for the hypogean ones. In this study, we conducted a comparative analysis of the available literature data on the sensitivity of freshwater copepods to agricultural pollutants. We also assessed the acute and chronic sensitivity of a hypogean and an epigean species, both belonging to the Crustacea Copepoda Cyclopoida Cyclopidae, to two N-fertilizers (urea and ammonium nitrate) and two herbicides (ARIANE(TM) II from Dow AgroSciences LLC, and Imazamox), widely used for cereal agriculture in Europe. According to the literature review, freshwater copepods are sensitive to a range of pesticides and N-fertilizers. Ecotoxicological studies on hypogean species of copepods account only one study. There are no standardized protocols available for acute and chronic toxicity tests for freshwater copepods, making comparisons about sensitivity difficult. From our experiments, ionized ammonia proved to be more toxic than the herbicide Imazamox, in both short and chronic bioassays. Urea was the less toxic chemical for both species. The hypogean species was more sensitive than the epigean one to all chemicals. For both species and for all tested chemicals, acute lethality and chronic lethality were induced at concentrations higher than the law limits of good water body quality in Europe, except for ionized ammonia, which provoked the chronic lethality of the hypogean species at a lower concentration. The hazardous concentration (HC) of un-ionized ammonia for 5 % of freshwater copepods, obtained by a species sensitivity distribution, was 92 μg l(-1), significantly lower than the HC computed for traditional test species from freshwater environments.

Isoclast Active Manufacture: In Situ Spectroscopic Investigation of the Unstable Products of Cyanamide and Sodium Hypochlorite Reactions

Isoclast Active is a new insecticide manufactured by Dow AgroSciences LLC. In an effort to lower the cost of manufacture of Isoclast Active, we have studied the reaction which produces N-cyano sulfilimine, which is the precursor to Isoclast Active. The reaction involves the oxidative coupling of cyanamide with the sulfide intermediate using sodium hypochlorite. In this study, we demonstrated that a transient intermediate species is produced by the reaction between bleach and cyanamide. On the basis of in situ Raman, IR, and NMR spectroscopic evidence we propose that the intermediate is the anionic form of N-chlorocyanamide: ClN––C≡N. The degradation of this intermediate species was found to be highly sensitive to its environment and leads to a complicated mixture of products. This work also demonstrates that in situ Raman and IR spectroscopy are powerful and invaluable tools for monitoring reactions/processes involving unstable reaction intermediates for kinetic modeling and process R&D.

Scientific Opinion on an application from Pioneer Hi‐Bred International and Dow AgroSciences LLC (EFSA‐GMO‐NL‐2005‐23) for placing on the market of genetically modified maize 59122 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003

This Scientific Opinion reports on a risk assessment on an application for placing on the market of genetically modified maize 59122 for import and processing for food and feed uses and cultivation. The EFSA GMO Panel considers that maize 59122 is unlikely to have any adverse effect on the environment, except for the possible evolution of resistance to the Cry34Ab1/Cry35Ab1 proteins in coleopteran target pests. The Panel recommends the implementation of appropriate and diversified insect resistance management strategies and case-specific monitoring to delay and monitor the possible evolution of resistance to Cry34Ab1/Cry35Ab1 in coleopteran target pests, respectively. In addition, the Panel recommends revision of the applicants’ insect resistance management plan and the proposed post-market environmental monitoring plan. Although maize 59122 is tolerant to glufosinate-ammonium-based herbicides, the Panel did not assess the potential adverse effects associated with the use of such herbicides on maize 59122, as maize 59122 will not be marketed in the European Union as a herbicide-tolerant crop. This Scientific Opinion updates the previous Panel safety evaluation of the food and feed uses, and import and processing of maize 59122 and derived products. The Panel concludes that the information available for maize 59122 addresses the scientific comments raised by Member States and that maize 59122, as described in this application, is as safe as its conventional counterpart and commercial maize varieties with respect to potential adverse effects on human and animal health. If subjected to appropriate management measures, the cultivation of maize 59122 is unlikely to raise safety concerns for the environment.

Composition of Grain and Forage from Insect-Protected and Herbicide-Tolerant Corn, MON 89034 × TC1507 × MON 88017 × DAS-59122-7 (SmartStax), Is Equivalent to That of Conventional Corn (Zea mays L.)

Monsanto Company and Dow AgroSciences LLC have developed the combined-trait corn product MON 89034 × TC1507 × MON 88017 × DAS-59122-7 (SmartStax, a registered trademark of Monsanto Technology LLC). The combination of four biotechnology-derived events into a single corn product (stacking) through conventional breeding provides broad protection against lepidopteran and corn rootworm insect pests as well as tolerance to the glyphosate and glufosinate-ammonium herbicide families. The purpose of the work described here was to assess whether the nutrient, antinutrient, and secondary metabolite levels in grain and forage tissues of the combined-trait product are comparable to those in conventional corn. Compositional analyses were conducted on grain and forage from SmartStax, a near-isogenic conventional corn hybrid (XE6001), and 14 conventional reference hybrids, grown at multiple locations across the United States. No statistically significant differences between SmartStax and conventional corn were observed for the 8 components analyzed in forage and for 46 of the 52 components analyzed in grain. The six significant differences observed in grain components (p < 0.05) were assessed in context of the natural variability for that component. These results demonstrate that the stacked product, SmartStax, produced through conventional breeding of four single-event products containing eight proteins, is compositionally equivalent to conventional corn, as previously demonstrated for the single-event products.

Designing optimal global supply chains at Dow AgroSciences

The design of the underlying supply chain network can have a tremendous impact on the profitability, manageability, and level of risk of a global supply chain. Taxes, duties, and tariffs vary from country to country as well as trading bloc to trading bloc and can consume as much as 10% of the revenues of certain products. In the highly regulated business environment of agricultural chemicals, the country of origin of an active ingredient can determine where the final product can be marketed and the amount of taxes and duties applied to the product, making it necessary to trace all batches of product through many layers of the supply chain to their sources. This article presents a mixed integer linear programming model in use at Dow AgroSciences LLC that simultaneously optimizes the network design underlying global supply chains and the monthly production and shipping schedules for maximum profitability. This work contributes to the supply chain design literature by demonstrating a novel method of tracing products to their source for inventory valuation, taxation, and duty computation in a production environment where the products change into other products as they pass through nodes in the network. It also demonstrates an iterative scheme for determining unit fixed costs for fixed cost allocation for the same purposes. Finally, it provides a case study of a supply chain design initiative in a global enterprise.

Ear Pests and Damage to Organic, Conventional and Bt-Protected Sweet Corn Grown in Central Kentucky

Sweet corn (Zea mays L. var. rugosa) was grown in replicated plots in 2004 and 2006 using organic, conventional, and genetically-engineered (Bt) production practices. Organic plots were treated with Entrust® (Dow AgroSciences LLC, Indianapolis, IN) whereas conventional and Bt sweet corn plots were treated with Warrior® (Syngenta Crop Protection, Inc., Greensboro, NC). All plots were treated once at silk emergence. Organic and conventional plots were treated again 1 wk later. Twenty-five ears were harvested from row centers in each treatment subplot to quantify ear pests and assess ear damage. The highest number of corn earworm, Helicoverpa zea (Boddie), larvae were found on organically-grown sweet corn. European corn borer, Ostrinia nubilalis (Hübner); southwestern corn borer, Diatraea grandiosella Dyar; and fall armyworm, Spodoptera frugiperda (J.E. Smith), larvae were not found as frequently. Neither corn earworm nor European corn borer larvae were found on Bt sweet corn ears. Sap beetles, Carpophilus lugubris Murray, were found on all 3 types of sweet corn. Organically and conventionally-grown sweet corn had a greater number of tip-damaged ears and numbers of damaged kernels per ear than Bt sweet corn. Ear length and weight were the same for all 3 types of sweet corn. Based on the information generated in this study, growing late-planted sweet corn organically or conventionally on a large commercial scale with a limited spray program and without using other types of ear pest management does not appear to be a practical or profitable option in central Kentucky.