Hill Geometry Influence On Irrigated Russet Burbank Yield and Grade

Field research was conducted the past four years at the Northern Plains Potato Grower’s Association Irrigation Research site near Tappen, ND to evaluate hill shape influence on ‘Russet Burbank’ growth, yield and tuber quality. Treatments consisted of: 1) no hill, 2) standard “Λ” shaped hill, 3) furrow planting, 4) "M" shaped hill, and 5) flat top hill. No other cultivation occurred after hills were formed. Furrow planting consisted of seed pieces planted in furrow rows that had hills made between the planted rows with disk openers. Hill formation for the remaining treatments with the exception of the no hill treatment occurred through modifications to the disk hiller. Every 2 weeks, beginning shortly after tuber initiation, 5 plants (tubers, roots, and shoots) were dug per treatment in each rep and measured, counted, and weighed. Treatment effect on plant growth, tuber yield, and tuber quality varied between years. It was obvious that weather greatly influenced hill shape’s effect on measured variables. For example, the standard “Λ” shaped hill had the greatest total yield during the cool growing conditions of 2004, but had the lowest total yield in 2007 when the weather was hot and it was difficult to maintain targeted soil water levels. In 2007, plants from the furrow planting, "M" shaped hill, and flat top hill treatments had greater yields than the total yield from plants in no hill or standard “Λ” shaped hill treatments. The furrow planting generally resulted in a lower tuber set and thus fewer tubers per plant at harvest, but a higher percentage of these tubers weighed 6 oz or greater. French fry sugar end percentage also varied amongst treatments depending upon the year. However, fries from  the standard “Λ” shaped hill treatment tended to have more sugar ends.