|MAHMOUD, MERVAT - University Of Missouri|
|SHARP, ROBERT - University Of Missouri|
|FINKE, DEBBIE - University Of Missouri|
|ELLERSIECK, MARK - University Of Missouri|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2016
Publication Date: 4/11/2016
Publication URL: http://handle.nal.usda.gov/10113/62318
Citation: Mahmoud, M.A., Sharp, R.E., Oliver, M.J., Finke, D.L., Ellersieck, M.R., Hibbard, B.E. 2016. The effect of western corn rootworm (Coleoptera: Chrysomelidae) and water deficit on maize performance under controlled conditions. Journal of Economic Entomology. 109:864-898.
Interpretive Summary: Both water deficit and western corn rootworm can dramatically affect maize yield. Previous anecdotal evidence in the field had suggested that when both plant stress factors were present, the effect on maize was greater than would be expected from the combined effects of the two factors alone. We conducted a series of greenhouse experiments using three infestation levels of the western corn rootworm under well-watered, moderately dry, and very dry soil moisture levels to quantify the effects of western corn rootworm and soil water deficit when found together under carefully controlled conditions. Overall, the effect of water deficit on maize growth was much greater than the effect of western corn rootworm and the combined effect on maize was no greater than expected from addition of the individual effects. A greater understanding of the effects of plant stress factors on maize growth will allow better decisions by growers as they attempt to optimize yield.
Technical Abstract: A series of greenhouse experiments using three infestation levels of the western corn rootworm, Diabrotica virgifera virgifera LeConte, under well-watered, moderately dry, and very dry soil moisture levels were conducted to quantify the interaction of western corn rootworm and soil water deficit on B73×Mo17 maize growth and physiology. Three separate experiments were conducted using neonate, 2nd instar, and western corn rootworm eggs. Soil moisture regimes were initiated 30 days post-planting in the neonate and the second instar experiments and 30 days post infestation in the egg experiment. In the neonate and second instar experiments, there was no significant differences between western corn rootworm levels in terms of leaf water potential, shoot dry weight, and root dry weight. The interaction of western corn rootworm and soil moisture significantly impacted the larval recovery in the neonate experiment, but no significant other interactions were documented between soil moisture levels and rootworm infestation levels. Overall, results indicate that under the conditions of these experiments, the effect of water deficit was much greater than the effect of western corn rootworm and that the interactions between water deficit and western corn rootworm levels minimally affected plant measurements.