Confounding Factors in Container-Based Drought Tolerance Assessments in Solanum tuberosum

Potato is an important food crop with high water-use-efficiency but low drought tolerance. The bottleneck in tolerance breeding phenotyping managed field environments. Fundamental research on predominantly done container-based test systems controlled However, the portability of results from these to performance under conditions debated. Thus, we analyzed effects climate conditions, container size, starting material, and substrate yield assessment potato genotypes compared trials. A leave one out indicated a minimum three trials for stable prediction. ranking was highly reproducible controlled-conditions, weakly correlated performance. Changing variable increasing substituting cuttings by seed tubers did not improve correlation. Substituting horticultural sandy soil resulted tuber size distributions similar those conditions. as effect treatment × genotype interaction low, indices that depend relative yields can be assessed also. Realistic estimates distribution, however, require use soil-based substrates.