Edge row effects on yields in an oat trial

Yield responses of oat (Avena sativa L.) genotypes to the presence of pathways between plots were examined in an irrigated field trial. Four replicates of 15 genotypes were sown in plots 18, m long, with 11 rows of plants. Yields were measured from the centre and both edge rows of each plot. Most genotypes yielded better in the edge rows than the centre row, but the extra yield gained from edge rows varied. Therefore, including edge rows into whole plot harvest when measuring the yield of cereal may bias genotype comparisons. The reliability of trial results could be improved by sowing wider plots and only harvesting the central section of each plot. Because differences in exposure to light seem to be a major factor in producing edge effects, orientating plots north-south would also be an advantage.