The simple effects of nitrogen rates, fungicide application, and varietal responses on wheat yield and quality have been studied individually, but interactions among the inputs are less well understood. Traditionally, increased nitrogen rates have led to higher risk of lodging and disease severity (Roth and Marshall, 1987), but it has been found that fungicides can be used to delay the onset of disease (Gooding et al. 1999). Similarly, yield responses to application of a fungicide may be affected by available nitrogen (Olesen et al., 2003). Wheat quality parameters such as protein, test weight, and alveograph parameters may also be affected by different management systems. Recent Ontario research shows interactions between fungicide and wheat varieties, even in the absence of disease, but the relationships are poorly understood. Current field crop recommendations would be improved by knowledge of interactions between inputs in more intensive management systems. Field experiments were established on nine farm fields in southwestern Ontario to investigate possible interactions among nitrogen rates, fungicides, and varieties. Eight fungicide timing combinations were applied as splits on three N rate blocks (100, 135, and 170 kg ha-1), applied across variety strips (between three and seven) in a split-strip-plot design with three replicates. Measurements included leaf disease severity, fusarium head blight incidence and severity and mycotoxin concentrations, grain yield and yield components, protein, test weight, and alveograph parameters. An economic analysis was performed on the combinations of treatment variables toward the development of more comprehensive recommendations. Interaction between N application rate and fungicide application resulted in greater yield gains with increased N when fungicides were used. Grain protein concentration increased at higher N application rates. Revenue net of the variable costs examined was not significantly affected by N rate alone, while effect of fungicide application varied with site. / Agricultural Adaptation Council, Grain Farmers of Ontario
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OGU.10214/3854 |
| Date | 16 August 2012 |
| Creators | Brinkman, Jonathan |
| Contributors | Hooker, David, Deen, Bill |
| 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 | Thesis |
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