SWEEP Report #19a
Weeds of Corn, Soybean, and Winter Wheat Fields Under Conventional, Conservation, and No-Till Management Systems in Southwestern Ontario - 1988 and 1989
(Weed Survey Series Publication 90-1, Agriculture Canada).
Evaluation Summary (Tech. Transfer Report Summaries)
View / Download Final Report [1585 KB pdf] (No Appendices)
Completed: November, 1990
corn, soybeans, winter wheat, no-till, survey, weed species, weed density, conventional tillage, conservation tillage, herbicide
NOTE: Figures and Tables referred to here are only available in the hardcopy report.
Conservation tillage has been defined as any method of tillage which leaves a minimum of 30% plant residue on the soil surface. Such systems include no-till and various systems which reduce the number of tillages, or use different types of tillage equipment other than the moldboard plow. Adoption of conservation tillage systems in agriculture could significantly reduce erosion, soil degradation, and water pollution. One of the main obstacles to widespread adoption of conservation tillage is the perception by farmers that new and exacerbated weed problems will occur when tillage is no longer available as a method of weed control.
Quantitative weed survey data are unavailable for most crops and regions in Ontario but a few studies have provided some information. Data on the distribution and abundance of weeds occurring in tomato and sweet corn fields of Essex, Kent, and Prince Edward Counties were published in 1964 by J. F. Alex (Weed Research 4:308-318). Corn, soybean, white bean, and mixed grain fields in Kent, Middlesex, and Perth Counties were surveyed by R. A. Richards (M.Sc. Thesis, University of Guelph, 1979). A survey of corn, soybean, cereal, and tomato fields in Essex and Kent Counties was also organized by A. S. Hamill during 1978 and 1979 (Publications 83-1 and 83-2 in the Weed Survey Series). In all these studies, only a small proportion of the province was included. Conventional tillage systems were assumed to have been used in these surveyed fields. Up-to-date quantitative data on weed populations under various tillage regimes throughout southern Ontario are needed.
The primary goal of the weed survey project, which is reported in this publication, is the identification of weed species likely to be the greatest problems under various tillage systems in southwestern Ontario. Information on the response of the weed community to changes in tillage practices is vital for a sensible farm management program. As well as the field survey for weeds, data on farm management practices were gathered through a questionnaire. This report is a summary of the results from 1988 and 1989.
The survey area is bounded by Lake Erie on the south and by the Detroit River, Lake St. Clair, St. Clair River, and Lake Huron on the west (Figure 1). The area extends north and east to 44° N latitude and to 80° W longitude. This southwestern corner of Ontario is part of the West St. Lawrence Lowland physiographic subdivision of Canada. All the area has been subjected to glacial erosion and deposition during the Pleistocene. Soils in the region are luvisols and gleysols, ranging in texture from sandy loam to clay, and formed on glacial till or lacustrine deposits. The topography varies from very gently undulating to rolling with elevations ranging from 175 m above sea level along Lake Erie to 500 m on the northern limit of the study area.
This report takes a lot of the information that is found in SWEEP Report #19 and presents it in the Agriculture Canada Weed Survey Series format. The tables, figures and appendices contained in this publication contain the raw survey data that could not be included in Report #19. The results of the survey are detailed in the first section, the results of the questionnaire survey are in the second section and an appendix of field survey summary tables is found at the back.
The report contains a lot of information that could be further analyzed to give more insight into the weed populations and shifts in southwestern Ontario. The questionnaire provides useful information on herbicide usage, tillage implements used, number of tillage passes and timing of herbicide application.
Future Research: ( ) indicates reviewers suggestion for priority, A - high, C - low.
(C) Conduct follow up surveys five years later.