By far the biggest change to The UK Pesticide Guide in 2020 is the loss of a number of active ingredients that have been fundamental to many crop protection programmes. The final use-up of chlorothalonil formulations; propiconazole, fenpropimorph, chloridazon and diquat occurs in 2020 but there are also a few of exciting new additions. Aclonifen is a new residual herbicide for use in potatoes that already has a number of EAMUs for use in minor crops. BASF is launching its new triazole, mefentrifluconazole , which promises to restore full triazole activity, at least initially. On the insecticide front the new active ingredient from Corteva agriscience, sulfoxaflor , is now listed for use in Cucurbitae and ornamentals under full protection for control of aphids and whitefly.