Evaluation of soybean cultivars for resistance to iron deficiency chlorosis in rows versus hills
Selection of a resistant cultivar is the most practical control measure for iron deficiency chlorosis in soybean (Glycine max L. Merr.). Plant breeders routinely evaluate cultivars for chlorosis resistance in hill plots, but this procedure may overestimate the chlorosis resistance of a cultivar. The objective of this research was to compare the chlorosis scores of soybean cultivars differing in chlorosis resistance, planted in conventional 76-cm rows, or with two, four, or eight plants per hill. In both 2001 and 2002, it was estimated that three plants per hill would give average chlorosis scores most similar to that observed in 76-cm rows. The highest overall precision was given with row plots, and the lowest with two plants per hill. Hill plots are more space-efficient than row plantings, but are much more easily lost due to animal predation.
soybean; iron deficiency chlorosis; cultivar screening; variety screening; hill plots; rows

