Mechanical weed control, chisel plow tillage and organic fertilization are important components of sustainable agriculture that can contribute to the preservation and improvement of soil and water resources. These practices can each affect weed communities, crop weed interactions and crop yields. Little is known about their combined effects on weed populations and weed community dynamics in common cropping systems. The main objective of this project was to determine the effects of crop rotation, weed control, tillage and nutrient source and their interactions on weed communities and weed emergence. The field experiment was conducted on a Sainte-Rosalie clay and a Duravin loam in Saint-Hyacinthe, Quebec, Canada, in 1996 and 1997. Mechanical control was not as effective as chemical control in controlling weed populations. Weed density increased after the second pass of the rotary hoe in soybean. Cultivation in corn triggered flushes of weed emergence, but corn yield was not affected by the increase in weed density. Chisel plow tillage reduced the efficacy of mechanical weed control in both crops. Reduced soybean yields were partly attributed to the large quantities of corn residues under chisel plow tillage. Nutrient source had no effect on weed densities. However, environmental stress conditions experienced in spring 1997 resulted in reduced crop growth and increased weed biomass under organic fertilization. Seed production of dominant residual weed species was greater under mechanical compared with chemical weed control, but was unaffected by tillage and nutrient source. Particular attention to weed management will be required when including both chisel plow tillage and organic nutrient source in a corn-soybean rotation, especially when resorting to mechanical weed control only.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20970 |
| Date | January 1998 |
| Creators | Perron, France. |
| Contributors | Legere, Anne (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Plant Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001657850, proquestno: MQ50854, Theses scanned by UMI/ProQuest. |
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