b'Somewhere along the way, when they designed equipment to do this, they may have just picked a row width that worked for [equipment manufacturers] and growers adapted to that, Pavek said in the webinar. And maybe it wasnt the most economically feasible row width, but its the one that worked with their equipment.Pavek disagreed with the equipment-focused way of thinking, so he conducted research on standard and optimized widths. We need to always question what were doing, he said. Can we improve it?In fact, he found that row width varies across the globe. In the U.S. and Canada, its typically in the 32 to 38-inch range, with variation depending on region, irrigation, season length and potato type. (Canada 34 to 38-inch; Columbia Basin: 22-inch and 34-inch; Oregon 34-inch and 36-inch; California 32-inch and 34-inch; Idaho 34-inch and 36-inch but beds with Paveks team planted in a unique star shape to test how sunlight capture and plant productivity 26-inch or 18-inch; seed and specialty cropsvaried by row orientation. 17-inch to 36-inch). In the UK, spacing varied between 28-inch and 30-inch in the 1960s, but expanded to 36-inch in thebased on irrigation starvation: the team wasThe number that matters most, of course, 1970s. Today, rather than a 36-inch toirrigating for a 34-inch row spacing, butis measured in dollars and cents. When the 36-inch consistent spacing, many growersmore tightly packed rows need more water).additional costs of planting more rows per use 34-inch to 38-inch variable spacingWhile average tuber weight didntacre (seed, fuel, equipment depreciation and to accommodate wide tires. Continentalchange, what did change was tuber numberslabour) were factored in, Paveks team found Europe tends towards a 30-inch spacingper plant. returns peaked around 32-inch. with skinny tires.Tuber count went from middle 7s [aboutWhat does that mean, at least for What can one expect if rows are moved7.3] to all the way up to 9.0 just by moving ourColumbia Basin growers? closer together? Pavek and his team plantedrows farther apart. When you move your rowsWe recommend growers in the nine varieties into trial plots at the WSUfarther apart, plants have less competition,Columbia Basin plant at 32-inch, says research farm near Othello, Washingtonthey feel like they can do more, so theyPavek. each year between 2011 and 2015. Theincrease the tuber number, Pavek said.To the many who are still on 34-inch plots were grown at full season, unlimitedYet, the total number of tubers harvestedspacing, he acknowledged: Its hard to irrigation with consistent 10-inch in-rowper acre remained consistent regardless ofchange especially when you have equipment spacing. The plots were grown at 30, 32,spacing, Pavek found.based on 34-inch. I recommend if growers 34, and 36-inch spacing in 2011 and 2012,At harvest, the tuber number that camewant to change, wait for your equipment to then realizing 36-inch was too wide for theover the belt was essentially unchanged.depreciate out and then your next round of Columbia Basin, the team switched to 28,Likewise, green tuber numbers wereequipment, get it set up for 32-inch.30, 32 and 34-inch spacing in 2013-2015. unchanged by row spacing.Tighter spacing could mean following The trial determined several keyIn terms of total and market yields, theEuropes lead on skinny tires with inset rear findings. First, as rows got closer together,results varied by variety. Averaged acrosstires on self-propelled harvesters in some vines grew taller. With more competition,varieties, Pavek said: We see that total yieldfields. If that doesnt work, growers might they had to grow longer to reach sunlight.peaks somewhere between 32-inch andconsider windrowing, Pavek said, to allow The important question is whether this30-inch row width.tighter rows and skinnier tires without risk growth was wasted energy that decreasedWhile the lower results at the tighterof bruising.total crop yield.end of planting was likely due to waterPavek provided this list of key takeaways Average tuber weight stayed fairlystarvation, the notable drop is at the highregarding row width:consistent (Pavek says the slightly lowerend of spacing: at 34-inch spacing, yield wasAre you ever concerned your potatoes are tuber weights seen in the 28-inch rows werenotably limited by the number of plants.too dry during the season? SPUDSMART.COMSpring 202455'