Integrating Spring Wheat Sowing Density with Variety Selection to Manage Wheat Stem Sawfly
- Brian L. Beres *ab,
- Héctor A. Cárcamoa,
- Rong-Cai Yangb and
- Dean M. Spanerb
The wheat stem sawfly [Cephus cinctus Norton (Hymenoptera: Cephidae)] (WSS) has been a serious pest of wheat (Triticum aestivum L.) since the late 19th century. Adoption of solid-stemmed cultivars, which are available only in the spring bread wheat class in Canada, can mitigate damage but the trait that confers resistance tends to be variable. Five other classes of wheat are grown within the geographical range of C. cinctus and are vulnerable to WSS infestation, and the entire production area for durum (T. turgidum L.) in western Canada, Montana, and western North Dakota lies within the geographic range of C. cinctus. Our objective was to test the hypothesis that the response of hollow- and solid-stemmed cultivars to sowing density (150, 250, 350, or 450 seeds m−2) would differ and subsequently affect infestation patterns of WSS and an endemic parasitoids. The lowest rates of infestation occurred in the hollow-stemmed durum cultivar AC Avonlea and declined with increased sowing density. Wheat pith expression was optimized at the lowest sowing density but the same level produced low and variable grain yield. In the solid-stemmed cultivar Lillian, pith expression was most stable at 250 or 350 seeds m−2. For all cultivars, grain yield was optimized at the higher seeding rates of 350 and 450 seeds m−2. Solid-stemmed wheat should be seeded at low to moderate density to maximize resistance to WSS, but hollow-stemmed cultivars should be seeded at higher seeding rates to optimize yield, lower WSS infestation, and to increase overall crop competitiveness.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2011. . Copyright © 2011 by the American Society of Agronomy, Inc.