Two uniformity experiments were conducted aiming to determine the optimal size and shape of potato plots under the conditions of Santa Maria, (RS). The first was established in August 29, 1991 and the second in March 19, 1992. The potato variety used was Baronesa. It was planted 0.80 and 0.33m between and within rows respectively. From the first planting date (normal date), 1152 samples of 0.80m² were harvested and from the second date (littie harvest) 1280 samples. The method proposed by GOMES (1984) was used to determine the optimal plot size and shape. The conclusions was that the optimal size for the normal planting is 20 basic units and for the littie harvest is 30 basic units including a border row at each side and one meter at the extremities. In regard to the plot shape, the best arrangement is four rows with five meters length each, in normal date, and five rows of six meters lenght each for the littie harvest.
size; shape; plots; uniformity experiments; potatos
