Optimization of Row Width and Seed Spacing for Red Norland

Abstract

Tablestock growers must produce high yields of optimally sized tubers to maximize market opportunities and economic returns. The effects of row width and seed spacing on tuber yield and profitability for Red Norland were evaluated in 2022 and 2023 near Becker, MN, using a split-plot factorial arrangement of treatments. Five row widths (71, 76, 81, 86, and 91 cm) and three seed spacings (20, 25, and 30 cm) were assessed. The 91 cm row width and 25 cm seed spacing are standard industry practices among growers in MN. Row width and seed spacing interactions were not significant for marketable yield. Marketable tuber yield increased by 13% for both 71 and 76 cm row widths, resulting to increased profits of $3,027 ha⁻¹ (71 cm) and 3,201 ha⁻¹ (76 cm), compared to the 91 cm industry standard row width. Tuber number increased by 8 to 16% at 20 cm seed spacing compared to 25 and 30 cm seed spacing. There was a profit increase of $788 ha⁻¹ from the 20 cm seed spacing compared to 25 cm seed spacing, while the 30 cm seed spacing decreased profits by $1,218 ha⁻¹. Narrower row-widths of 71 and 76 cm and closer seed spacing of 20 cm enhanced yield and grower returns.