Pyralid weedkillers in compost 2: amino- and clopyralid, effects and healing

Small residues of this persistent product are now present in many composts, even “organic” ones. I show how to check for their presence by growing bean and pea seedlings. Testing like this is called a bio-assay, and is more effective than laboratory testing, partly because the amounts of active compound are so tiny. Many lab tests show as “negative”, when poison is there and causing damage.