Two experiments were conducted between 1983 and 1985. In each case, timothy was established with or without barley, red clover, broadleaf weeds and grassy weeds. Four and six weeks after seeding, botanical composition, soil water-content, soil nutrient-content, light interception, and plant coverage data were obtained. The plots were then harvested once during establishment year and twice during subsequent years. At harvest, yield, botanical composition, and forage quality were obtained. Companion-cropping precluded forage cut during establishment and decreased forage yield during the first production year. Establishment with barley had little effect on forage quality but it favored the development of perennial broadleaf weeds. Inter-cropping with red clover decreased timothy yield but total forage production was increased and forage quality was improved. Red clover also reduced the development of perennial broadleaf weeds. The absence of broadleaf weed control increased productivity during establishment but timothy contribution was reduced and perennial broadleaf weeds development was accelerated. Perennial broadleaf weeds reduced yields during the first production year. Establishment without grassy weed control increased yield during establishment (but quality was lessened) and reduced it during the first production year. Establishment with grassy weeds had little effect on the weeds growing thereafter. In presence of both types of weeds, the grassy species were suppressed and the results reflected the situation observed in presence of broadleaf weeds. Finally, principal component analyses showed 12 factors that could be used to predict crop yield. The interpretation suggested that early measurements of weed density along with weed and crop coverage data would give good predictions of crop loss.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75357 |
| Date | January 1986 |
| Creators | Lemieux, Claudel |
| 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 | Doctor of Philosophy (Department of Plant Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000573139, proquestno: AAINL38279, Theses scanned by UMI/ProQuest. |
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