|Brewer, M - UNIV. OF WYOMING|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2002
Publication Date: October 21, 2001
Citation: MORNHINWEG, D.W., PORTER, D.R., BREWER, M., WEBSTER, J.A. FIELD ASSESSMENT OF AGRONOMIC PERFORMANCE OF UNADAPTED RWA-RESISTANT BARLEY GERMPLASM LINES. AGRONOMY ABSTRACTS. 2001. AGRONOMY PAPER NO. 114411-P. Technical Abstract: Russian wheat aphid (RWA), Diruaphis noxia(Mordvilko), is a devastating pest on barley in the intermountain region of the western U.S. Unadapted RWA-resistant lines have been developed by the USDA-ARS in Stillwater, OK with differing levels of resistance based on seedling screening in the greenhouse. A small sample of lines had been tested in the greenhouse with RWA infestation throughout the life of the plant determining that resistance was ontogenetic. The objectives of this study were to determine if RWA resistance ratings, based on visual damage symptoms of seedlings in the greenhouse, accurately predict field resistance measured as grain yield and malting quality, and to determine the effect of RWA infestation on grain yield, yield components, and malting quality. Nineteen unadapted barley germplasm lines, varying in RWA resistance rating from 2 to 9, were grown in the field in Wyoming for two years under both RWA-infested and non-infested conditions. The prediction of grain yield performance based on greenhouse seedling resistance rating was very accurate. Lines rated resistant (2-3) as seedlings in the greenhouse were resistant in the field with no reduction in grain yield. Moderately resistant lines (rated 4-5) had an intermediate response to RWA with non-significant decrease in grain yield. Moderately susceptible lines (rated 6) had the same significant decrease in grain yield as the susceptible cultivar checks. The malting quality of these unadapted lines was so poor that accurate measurements of further negative effects on malting quality in response to aphid feeding were unattainable. Malting quality of the adapted susceptible cultivars was severely affected by RWA feeding.