Author Institution: Department of Agronomy, The Ohio State UniversityApplication of large amounts of phosphorus fertilizers is used to enhance early plant growth and yield of wheat (Triticum aestivum L.). This practice can lead to an accumulation of phosphorus in soil and a reduced copper uptake by plants which may result in a reduction of plastocyanin concentrations in chloroplasts. As a result, photosynthetic rates and crop yield can be adversely affected. While copper uptake is sometimes enhanced by vesicular-arbuscular mycorrhizal (VAM) fungi, large accumulations of soil phosphorus can reduce VAM-enhanced copper uptake