title: Effects of Carriers, Emulsifiers, and Biopesticides for Direct Silk Treatments on Caterpillar Feeding Damage and Ear Development in Sweet Corn.
abstract: In the northeastern United States, control of Lepidopteran pests of sweet corn, particularly corn earworm [Helicoverpa zea (Boddie)], is difficult using organic methods. The direct application of corn oil and Bacillus thuringiensis (Bt) to corn silk has been shown to reduce ear damage from corn earworm in past studies; these studies sought to optimize this method by evaluating additional carrier and biopesticide mixtures that comply with the United States Federal Insecticide, Fungicide, and Rodenticide Act and National Organic Standards. Carriers, which are liquids used to dissolve the biopesticide and deliver it into the tip of the ear, may have phytotoxic or insecticidal properties. Experiments conducted from 2001 to 2005 evaluated caterpillar damage and ear development effects from carriers (vegetable and paraffinic oils and carrageenan), biopesticides (Bt, spinsosad, and neem), and three emulsifiers in various combinations when applied directly to the tips of the ears 5-7 d after silk initiation. There were no effects of emulsifiers on ear quality, except for slight reduction in caterpillar damage in one of the two years. There were no differences among corn, soy, canola, and safflower oils in corn earworm control or tip development. The carrageenan carrier had the least effect upon ear development as measured by the length of nonpollinated kernels at the tip, compared to corn oil or paraffinic oil (JMS Stylet Oil), which caused the greatest tip damage as well as an oily discoloration. The carrier-pesticide combinations with the best ear quality overall were spinosad in carrageenan or corn oil, and Bt in carrageenan.
authors.affiliation: Kleinfelder Inc., 500 Enterprise Dr., Suite 4B, Rocky Hill, CT 06067 (PWestgate@kleinfelder.com).
authors.forename: P J
authors.initials: PJ
authors.lastname: Westgate
authors.affiliation: School of Natural Science, Hampshire College, Amherst, MA 01002 (bschultz@hampshire.edu).
authors.forename: B B
authors.initials: BB
authors.lastname: Schultz
authors.affiliation: UMass Extension, Center for Agriculture, Food & the Environment, 250 Natural Resources Rd., University of Massachusetts, Amherst, MA 01003 (rhazzard@umass.edu).
authors.forename: R V
authors.initials: RV
authors.lastname: Hazzard
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics; D002351:Carrageenan / Q000737:chemistry / Q000494:pharmacology; D000069601:Crop Protection / Q000379:methods*; D004337:Drug Carriers; D004338:Drug Combinations; D045703:Emulsifying Agents / Q000737:chemistry / Q000494:pharmacology; D005989:Glycerides / Q000737:chemistry / Q000494:pharmacology; D007300:Insect Control / Q000379:methods; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology*; D018942:Macrolides / Q000494:pharmacology; D008404:Massachusetts; D009036:Moths / Q000187:drug effects*; D009821:Oils / Q000737:chemistry / Q000494:pharmacology; D010232:Paraffin / Q000737:chemistry / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D030821:Plants, Genetically Modified; D013729:Terpenes / Q000737:chemistry / Q000494:pharmacology; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development*
chemical_list: D004337:Drug Carriers; D004338:Drug Combinations; D045703:Emulsifying Agents; D005989:Glycerides; D007306:Insecticides; D018942:Macrolides; D009821:Oils; D010938:Plant Oils; D013729:Terpenes; C002443:neem oil; D010232:Paraffin; C015418:paraffin oils; D002351:Carrageenan; C415329:spinosad
keywords: Helicoverpa zea; biopesticide; direct silk application; sweet corn; tip fill