Title page for ETD etd-05022009-040359


Type of Document Master's Thesis
Author Laub, Curtis A.
URN etd-05022009-040359
Title Influence of cover crop management on Armyworm, Pseudaletia Unipuncta (Haworth) seasonal abundance, natural enemies, and yield in no-till corn, and diurnal abundance and spatial distribution of Armyworm
Degree Master of Science
Department Entomology
Advisory Committee
Advisor Name Title
No Advisors Found
Keywords
  • Cover crops
Date of Defense 1990-04-10
Availability restricted
Abstract

Rye (Secale cereale L.) used as a winter cover crop was killed by paraquat or by mowing with a bushog. In subsequent no-till corn, early season armyworm, Pseudaletia unipuncta (Lepidoptera: Noctuidae) abundance was lower in the mowed treatment compared with the sprayed treatment. Total cumulative armyworm-days in the sprayed treatment were greater than in the mowed treatment and were significantly greater in the sprayed treatment in two fields. Lower armyworm populations may have resulted from a combination of mowing which physically destroyed some larvae, and predation by generalist predators attracted to the moist conditions provided by the mulch of mowed rye. Twelve species of parasitoids attacked armyworm. Glyptapanteles 111ilitaris (Walsh) (Hymenoptera: Braconidae) and Periscepsia laevigata (Wulp) (Diptera: Tachinidae) were the most abundant parasitoids. Seasonal parasitization rates ranged from 36-45%. Parasitism did not differ significantly between treatments. Mowing the cover crop was 40% less expensive than spraying. Corn silage yields did not differ significantly between treatments, but the average increase in net benefit from mowing compared to spraying was $91-113/ha.

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