WHEAT SEED (TRITICUM AESTIVUM L.) RADIOCARBON CONCENTRATION OVER THE LAST 75 YEARS

ABSTRACT Here we report radiocarbon measurements made on wheat seed tissue (Triticum aestivum L.; winter or spring type growth habit), from the seed archive of the IPK Gatersleben, Sachsen-Anhalt, Germany, which was harvested between 1946 and 2020. The results give an overview of 75 years of radiocarbon concentration evolution in agricultural plant products. The wheat tissue radiocarbon concentrations follow known pre- and post-bomb radiocarbon records, such as the atmospheric Jungfraujoch, Schauinsland, and NH1 datasets. Based on a Northern Hemisphere growing period from April to July, the Gatersleben seed tissue radiocarbon concentration indicates incorporation of fossil carbon of about 1% with respect to the high alpine, clean-air CO2 of the Jungfraujoch station between 1987 and 2019. We propose to use the pre- and post-bomb radiocarbon record of Gatersleben wheat as a reference in forensic investigations, such as the age estimation of paper by analyzing starch used in paper manufacture. Additionally, an advantage of the record reported here lies in its extensibility by adding new analyses from future harvests.

Use of Uptake Spraying Oil to Improve Fungicidal Activity of the Triazole Fungicide Fenbuconazole on Puccinia triticina and Puccinia striiformis Rusts of Wheat

Fenbuconazole, a broad spectrum triazole fungicide with restricted uptake and consequent redistribution within wheat plants, has been perceived to possess limited curative properties when formulated as a suspension concentrate (SC). Field and greenhouse studies demonstrated that curative and to a lesser extent protectant activity of fenbuconazole on wheat leaf rust (Puccinia triticina) and stripe rust (Puccinia striiformis f.sp. tritici) was improved by the addition of the adjuvant Uptake™ Spraying Oil (Uptake is a trademark of Dow AgroSciences). The purpose of this study was to determine if the addition of adjuvant increased penetration of fenbuconazole into wheat tissue and if this was correlated with enhanced redistribution within the plant and the observed increase in activity. These data confirm that the addition of adjuvant improved penetration of fenbuconazole into wheat leaves and was responsible for the observed increase in biological activity of the fenbuconazole suspension concentrate formulation. In addition, adjuvant decreased the amount of material washed off with water a result suggesting the potential for improved rain-fastness in the field. Fenbuconazole's fungicidal activity against cereal rusts could be limited by poor penetration into plant tissue unless a suitable adjuvant is incorporated into the spray solution. Accepted for publication 31 January 2013. Published 28 May 2013.