A 2-yr field study was used to examine the main effects and interactions of western corn root worm (WCR), Diabrotica virgifera virgifera LeConte, infestations, nitrogen (N), and corn plant population levels on larval survival and damage, and root growth response. Nitrogen application and higher plant density treatments increased adult emergence, although there were significant N by plant density interactions both years. In 1985, root damage ratings increased with moderate N application but decreased with high N levels. Plant density treatments had no effect on damage ratings. Nitrogen application in 1985 decreased lodging by 44% in plants injured by WCR. Increased N and low to moderate plant population levels resulted in larger root systems and greater regrowth and brace root development. A significant N by plant density interaction indicated that a high plant population level negated the positive response of brace root development to increased N application. WCR infestation promoted root regrowth and brace root development. Decreased adult emergence, root damage ratings, lodging, and increased root regeneration were observed in 1984, a year characterized by excessive June rainfall and saturated soil conditions. These results suggest that N, plant population, and soil moisture levels are contributing factors in WCR larval survival and recovery of the corn plant root system.
Document Type: Research Article
Publication date: October 1, 1988
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.