Influence of development stage of spring oilseed rape and spring

10 The dry and wet deposition of radionuclides released into the atmosphere can be 11 intercepted by vegetation in terrestrial ecosystems. The aim of this study was to quantify the 12 interception of wet deposited Cs and Sr by spring oilseed rape (Brassíca napus L.) and 13 spring wheat (Tríticum aestívum L.). The dependency of the intercepted fraction (f) on total 14 above ground plant biomass, growing stage and the Leaf Area Index (LAI) was quantified. A 15 trial was established in Uppsala (east central Sweden), with land management in accordance 16 to common agricultural practices. The field trial was a randomised block design of 1 × 1 m 17 parcels with three replicates. During the growing season of 2010, a rainfall simulator 18 deposited Cs and Sr during six different growth stages. Two to three hours after 19 deposition, the biomass of the centre 25 × 25 cm area of each parcel was sampled and above 20 ground biomass and LAI were measured. The radioactivity concentration and radioactivity of 21 samples were measured by High Purity Germanium (HPGe)-detectors. 22 For Cs, there was a correlation between f and LAI (r = 0.55, p < 0.05) for spring 23 wheat, but not for spring oilseed rape (r = 0.28, p > 0.05). For Sr, there was a correlation 24 between f and LAI for both crops (r = 0.41, p < 0.05 for spring oilseed rape and r = 0.48 p, < 25