Distribution of 14C-glyphosate in legumes parasitised by Orobanche crenata

Absorption and translocation of ¹⁴C-glyphosate was evaluated under controlled conditions in peas ( Pisum sativum L.) and broad beans ( Vicia faba L.) parasitised or not by crenate broomrape Orobanche crenata Forsk.). Absorption increased with time up to 12 days after treatment, and reached about 50% of the ¹⁴C-glyphosate applied. Three days after treatment 70–85% of the total herbicide absorbed had been translocated out of the treated leaflet. There was no consistent differ ence in absorption and translocation between infected and non-infected plants 12 days after treatment. The ¹⁴C-glyphosate concentration in the root system increased with time in broad beans. In peas it remained more or less constant from 3 days after treatment. Generally, pods were stronger sinks for glyphosate than other parts of the plant. Herbicide accumulation in broomrape increased with its growth stage, and the parasite was a much stronger sink for glyphosate than the legume root system.