Plant Density and Equidistant Spacing Effects On Tuber Yield and Tuber Size in Red Norland Potatoes.

Standard planting of potatoes has traditionally been between row spacing of 91 cm and individual plant spacing of 23 cm within rows. This traditional spacing practice can be improved upon as it does not provide the best conditions for higher yields, higher amounts produced and a smaller, more desirable tuber size. This experiment is being conducted to discern how plant spacing influences the yield, amount and size of tubers produced. Three blocks were created to conduct this experiment, each block consisting of five 9 m² plots. The equidistant arrangements tested were 18 cm by 23 cm, 25 cm by 30.5 cm, 33 cm by 38, and 38 cm by 45.5 cm. The traditional 91 cm row spacing was used as a constant. The treatments were randomized and tested once in each block. The potatoes were hand planted on May 20^th, 2011 and the plots were sprayed pre-emergently with the herbicides Sencor, Eptam and Matrix.  In previous experiments yield was higher with closer plant spacing. Data collected in 2008 and 2009 shows that yields came in at 26 and 65 Mg/ha^-1 for the control and 51 and 75 Mg/ha^-1 for the 18 cm by 23 cm equidistant spacing. The amount of tubers was also higher at closer plant spacing with 4X10⁵ tubers produced in 2008 and 2009 for the control and 8.8X10⁵ tubers produced in 2008 and 12X10⁵ tubers produced in 2009 for the 18 cm by 23 cm equidistant spacing. When looking at tuber size among the different equidistant spacings and control, the 18 cm by 23 cm spacing had the smallest, mean tuber size at 51 g. All in all, based on previous experiments higher yields, amounts and smaller tuber sizes are expected as plant spacing decreases for this experiment.