| Abstract: | Phosphorus (P) fertilizer is routinely applied to potato (Solanum tuberosum L.) in Manitoba, Canada; however, little information is available regarding P responses in this region. Field studies were conducted from 2003 through 2006 to determine the impact of P rate 0, 15, 29, 43 kg P ha?1 as broadcast incorporated monoammonium phosphate (MAP)] on Russet Burbank potato. Increasing P rate resulted in a linear increase in marketable yield in 2005, a quadratic increase in 2006, and no effect in 2003 and 2004. Phosphorus application had no effect on the yield of tubers <85 g, tuber number, or quality, but petiole P concentration and postharvest soil-test P levels increased with increasing P rate. Results of this and other studies show that P fertilization may improve potato yields, although increases are not completely predictable. Additional research is required to refine soil-test guidelines and petiole P sufficiency levels for this region. |
