Impact of applying edible oils to silk channels on ear pests of sweet corn

J Econ Entomol. 2011 Jun;104(3):956-64. doi: 10.1603/ec10356.

Abstract

The impact of applying edible oils to corn silks on ear-feeding insects in sweet corn, Zea mays L., production was evaluated in 2006 and 2007. Six edible oils used in this experiment were canola, corn, olive, peanut, sesame, and soybean. Water and two commercial insecticidal oils (Neemix neem oil and nC21 Sunspray Ultrafine, a horticultural mineral oil) were used as the controls for the experiment. Six parameters evaluated in this experiment were corn earworm [Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)] damage rating, the number of sap beetle [Carpophilus spp. (Coleoptera: Nitidulidae)] adults and larvae, the number of corn silk fly (or picture-winged fly) (Diptera: Ulidiidae) larvae, common smut [Ustilago maydis (D.C.) Corda] infection rate, and corn husk coverage. Among the two control treatments, neem oil reduced corn earworm damage at both pre- and postpollination applications in 2006, but not in 2007, whereas the mineral oil applied at postpollination treatments reduced corn earworm damage in both years. The mineral oil also reduced the number of sap beetle adults, whereas the neem oil applied at postpollination attracted the most sap beetle adults in 2007. Among the six edible oil treatments, the corn and sesame oils applied at postpollination reduced corn earworm damage only in 2007. The application of the peanut oil at postpollination attracted more sap beetle adults in 2006, and more sap beetle larvae in 2007. Olive and neem oils significantly reduced husk coverage compared with the water control in both years. The mineral oil application consistently increased smut infection rate in both 2006 and 2007. Ramifications of using oil treatments in ear pest management also are discussed.

MeSH terms

  • Animals
  • Coleoptera
  • Diptera
  • Georgia
  • Glycerides
  • Insect Control / methods*
  • Insecta*
  • Insecticides*
  • Mineral Oil
  • Moths
  • Pest Control, Biological / methods
  • Plant Oils*
  • Pollination
  • Species Specificity
  • Terpenes
  • Ustilago
  • Zea mays / growth & development*

Substances

  • Glycerides
  • Insecticides
  • Plant Oils
  • Terpenes
  • neem oil
  • Mineral Oil