Yield Losses in Winter Wheat Caused by Low-Density Cereal Aphid Populations
- R. W. Kieckhefer* and
- J. L. Gellner
In most autumns on the Northern Plains of the USA, low population densities of several species of cereal aphids feed on seedling winter wheat, Triticum aestivum L., for a month or more. The objective of this research was to determine the influence of that feeding on the growth and yield of ‘Rose’ winter wheat. Experiments were conducted by confining non-viruliferous (barley yellow dwarf virus) greenbug, Schizaphis graminum (Rondani), at precisely maintained population densities of 2, 4, 6, 8, 10, and 15 aphids per plant, bird cherry oat aphids, Rhopalosiphum padi (L.), at densities of 10 or 15 aphids per plant, or Russian wheat aphids, Diuraphis noxia (Mordvilko), at 5, 10, 15, and 20 aphids per plant on seedling plants for 30 d in an environmental chamber at 10°C (to simulate mean October temperature in the field), 12 h day/night. The results showed that the threshold for significant yield loss under these environmental conditions was at the 10 aphids per plant level for the bird cherry oat aphid and the Russian wheat aphid, and 15 apbids per plant for greenbug. Yield losses caused by any of the aphid species were in the range of 35 to 40% at 15 aphids per plant. Although the visible injury to plants caused by the feeding of the greenbug and the Russian wheat aphid was striking, the bird cherry oat aphid was as damaging to yield as the other two species in this study.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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