Minimum plot size to evaluate potato tuber yield traits

The proper plot size is essential to reduce experimental error and thereby maximize precision of data obtained in an experiment. The objective of this work was to estimate the minimum number of plants per plot to assess tuber yield traits of potato genotypes. Four advanced potato clones (F161-07-02, F189-06-09, F97-08-07 and F131-08-06) of the breeding program of Embrapa were evaluated. The experiment was conducted in the fall season of 2015, in Canoinhas, Santa Catarina State, Brazil. A randomized complete block design with two replications of 20-plant two-row plots was used. At 112 days after planting, plants of each plot were individually harvested and evaluated for tuber yield traits. The modified maximum curvature and the repeatability methods were used to estimate the minimum plant number to represent the genotypes in each plot. We found that 10 to 14 plants per plot arc enough to guarantee an adequate precision and predict the real value of the individuals for tuber yield traits in experiments of two replications, considering an R2 of 90% for the repeatability method.