Tillage and seed-sprouting strategies to improve potato yield and quality in short season climates

Management practices that accelerate crop development and allow earlier harvest would be beneficial in short-season potato (Solanum tuberosum L.) production areas. Yield and quality of the potato cultivar 'Russet Burbank' were evaluated in a 2-yr study in northern Maine to determine effects of soil tillage and seed-sprouting treatments designed to dry soil early in the spring and hasten seed emergence. The tillage treatments, consisting of fall raised bed (RB), fall ridge tin (RT), and spring chisel plow (CH), were tested in combination with green-sprouted and non-sprouted seed tubers on a Caribou gravelly loam (coarse-loamy, mixed, frigid, Typic Haplorthod). Plants from green-sprouted seed emerged earlier than from non-sprouted seed tubers (87%-96% vs 21%-37%, respectively, at 18 days after planting [DAP] in 2000; and 73%-88% vs 18%-23%, respectively, at 20 DAP in 2001). Green-sprouted seed tubers in RB yielded 4.6 to 5.9 T ha(-1) more than nonsprouted seed tubers in RB. However, non-sprouted seed tubers yielded higher than green-sprouted seed tubers in RT by 2.9 to 4.2 T ha(-1) and in CH by 1.1 to 4.1 T ha(-1). Similarly, green-sprouted seed tubers in RB and nonsprouted seed tubers in RT and CH produced higher marketable yield, greater tuber length, and greater tuber diameter than the corresponding seed-sprouting treatment. In the comparatively wetter year (2000), the use of green-sprouted seed tubers in RB significantly increased total and marketable yields, and produced longer and larger tubers than all other treatments. However, in 2001 (relatively dry year), yield and quality from green-sprouted seed tubers in RB did not differ from non-sprouted seed in RT or CH. Green-sprouted seed produced fewer sunburned and rotten tubers, but more misshapen tubers than non-sprouted seed in RB tillage. The technique of producing Russet Burbank potatoes in raised beds is a promising system in regions with short growing seasons for enhancing early soil drainage during spring and improving soil water retention during critical periods of crop growth and development.