Persistence of 14C-ethylenethiourea in brinjal plants and soil

14C-ethylenethiourea, ETU, (8.6mg) applied to 12 leaves on the plant dissipated quickly to 28% after 3 days. After 4 weeks, the treated leaves contained only 0.25%. Residues in all fruits were only 0.47 μg after 3 days, increasing to 3.31 μg after 2 weeks and declining to 0.69 μg after 8 weeks. Ethyleneurea (EU) was undetectable in fruits after 3 days. Seven-day samples contained 1.0 μg, increasing to 3.15 μg after 2 weeks and declining to 1.2 μg after 8 weeks. The persistence and leaching of 14C-ETU was studied in soil-filled PVC columns under irrigated and non-irrigated conditions. Each column was treated with 3.27 mg ETU/1.365 μCi in 10 ml water and radioactivity was determined for various depths over a period of 52 days. Under non-irrigated and irrigated conditions, the major 14C-activity was retained in the top 10 cm of soil with only < 2% and < 4% leaching to lower depths, respectively. In the absence of moisture, soil contained 75% of the applied ETU after 22 days. In irrigated soils, 54% was found in soil after 25 days; this declined to 30% after 52 days. (author)