Tuesday, November 14, 2006

A Correlative Study of Percent Stunting and Yield in Barley Yellow Dwarf Virus (BYDV) Infected Plants.

Andrea Collett1, Fredric Kolb2, Eric Brucker2, and Norman Smith2. (1) Univ of Illinois at Champaign-Urbana, 1102 S. Goodwin, Urbana, IL 61801, (2) Univ of Illinois at Urbana, 1102 S. Goodwin, Urbana, IL 61801

Barley yellow dwarf (BYD) is a viral disease vectored by aphids.  This disease causes economic yield losses in small grains including wheat, oats and barley.  Symptoms include stunting, yellowing or reddening of the leaves, and a slight thickening of the leaves.  Assessing severity of BYD is difficult in wheat because of the subtle range of visual symptoms.  Our objective in this experiment was to determine the correlation between percent stunting and yield loss due to BYDV.  Percent stunting and yield were evaluated in a field experiment using three replications of hill plots with three treatments: inoculated, natural, and Gaucho® (imidocloprid) treated.  The experiment included sixteen winter wheat lines and was conducted at Urbana, IL for two years.  Plants were inoculated at the three leaf stage by applying aphids carrying the PAV-IL strain of BYDV.  Aphids were not applied to plants in the natural infection group. Gaucho® treated plants were used as an uninfected control from which percent stunting was calculated.  Plant height and yield were recorded each year, and in the second year disease severity was evaluated on a scale from 0 to 9.  Results on the correlation between percent stunting and percent yield loss will be reported.  If there is a correlation, percent stunting could be used to evaluate disease severity making selection more efficient and rating less subjective.