Soil-to-grain transfer of fallout 90Sr for 28 winter wheat cultivars

In order to identify wheat cultivars with minimum soil-to-grain transfer of fallout Sr-90, 28 winter wheat cultivars were investigated at three different sites with different soil types in Upper Bavaria. Each cultivar was grown on an area of 10 m(2) and harvested in August 1999. Mean soil-to-grain concentration ratios (C-r) were 0.151 +/- 0.029, 0.205 +/- 0.035 and 0.060 +/- 0.012, respectively. The Cr values obtained varied by factors of up to 2.6 for the different cultivars at a given site, and by factors of up to 5.0 for the different sites and a given cultivar. Site-averaged normalized concentration ratios (SANC(r)) ranged from 0.666 +/- 0.062 to 1.503 +/- 0.161. The cultivars Convent, Ludwig, and Semper, showed the lowest uptake of Sr-90 compared to the mean of all cultivars at each site. A cultivar that shows both minimum uptake of Sr-90 and Cs-137 could not be identified. The results suggest that Sr-90 rather than Cs-137 might be the limiting radionuclide concerning the use of contaminated land for wheat production. Thus, more efforts might be necessary identifying wheat cultivars with minimum Sr-90 uptake.