Hostname: page-component-7b7567c8c-wxvwp Total loading time: 0 Render date: 2026-11-14T22:29:20.532Z Has data issue: false hasContentIssue false

Yield Loss Assessment for Spring Wheat (Triticum aestivum) Infested with Canada Thistle (Cirsium arvense)

Published online by Cambridge University Press:  12 June 2017

William W. Donald
Affiliation:
Cropping Systems and Water Quality Res. Unit, USDA-ARS, 244 Agric. Engr. Bldg., UMC, Columbia, MO 65211
Mohammad Khan
Affiliation:
Agric. Res. Inst., Tarnab (Peshawar) NWFP, Pakistan

Abstract

In eight of nine trials spanning 5 yr, relative yield of semidwarf hard red spring wheat (yield expressed as a percent of estimated weed-free yield) decreased linearly as Canada thistle shoot density increased when measured in late July to early August in the northern Great Plains. Differences between yield loss assessment (YLA) equations could not be distinguished statistically between no-tillage and chisel-plowed production systems. Multiple linear regression equations of relative wheat yield versus wheat density plus Canada thistle shoot density accounted for more variability in YLA equations than simple linear regression equations of wheat yield versus Canada thistle shoot density alone. Estimated weed-free wheat yield and negative slope (b) for yield loss assessment equations increased as cumulative growing-season (April to August) rainfall increased. Thus, relative wheat yield was decreased more by increasing Canada thistle density (slope b became more negative) in years of greater growing-season rainfall.

Information

Type
Weed Control and Herbicide Technology
Copyright
Copyright © 1992 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable