Improving Phosphorus Management on Irrigated Potato

Assessed the effect of phosphorus management on potato yield and quality under Manitoba’s irrigated production systems.


27 Feb 2004

2003 Annual Interpretive Summary

Improving Phosphorus Management in Irrigated Potato Production Systems, 2003

Rapid expansion of the processing potato industry in Manitoba has generated a need for information regarding fertilizer management strategies for irrigated potato. The first year of a 3-year study was conducted in 2003 to determine the impact of phosphorus (P) fertilizer rate on potato tuber yield and quality, and the effectiveness of petiole P concentration in assessing P status of potato (cv. Russet Burbank).

A field experiment was conducted at one location near Carberry in 2003 to assess the effect of four P rates (0, 30, 60, and 90 lb P2O5/A as broadcast/incorporated monoammonium phosphate) on tuber yield and quality, petiole P status, and post-harvest soil P status. Preliminary analysis indicated that P fertilizer rate had no effect on total tuber yield, which averaged 380 cwt/A, or on tuber size distribution. Specific gravity of tubers was lower for the highest P rate compared to the other treatments. Preliminary soil test results indicated that NaHCO3-extractable P levels for the plot area averaged 13 parts per million (ppm), 0 to 6 in., which would have resulted in a recommendation for application of 40 to 45 lb P2O5/A based on provincial guidelines. Analysis of petiole and soil samples is ongoing. Studies will continue in 2004. MB-19F