Topography and Management of Nitrogen and Fungicide Affects Diseases and Productivity of Canola
2005
Kutcher, H. R. | Malhi, S. S. | Gill, K. S.
Successful application of precision agriculture technology requires information on crop response to many factors including fertilization and disease management. Field experiments were conducted on a hummocky landscape in the northern prairies to determine effects of slope (SL) position, N fertilization, and fungicide (FU) application on disease incidence, biomass yield, and seed yield, quality, N uptake, and recovery of applied fertilizer N for canola (Brassica napus L.). As N rate was increased, blackleg [Leptosphaeria maculans (Desmaz.) Ces. & De Not] disease incidence, biomass yield, and seed yield, protein content, N uptake, and percentage green increased while emergence, thousand-seed weight, and seed oil content and recovery of fertilizer N declined. The response of seed yield to N fertilization was relatively greater at upper than at the lower SL position, indicating the fertilizer N requirement for optimum seed yield was less at lower (71 kg N ha⁻¹) than upper (88 kg N ha⁻¹) SL. The upper SL had higher blackleg incidence and seed oil content than the lower SL. Therefore, FU application to control blackleg tended to be more beneficial for high N rates at the upper SL position. Sclerotinia stem rot [Sclerotinia sclerotiorum (Lib.) de Bary] did not appear to vary between management units. The results indicate some potential to use precision agriculture based on topography to guide disease control and N fertilizer strategies although each disease must be considered individually and with consideration for other management practices and environmental conditions.
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