From 2009 through 2016 IR-4 completed 155 trials evaluating Biathlon (oxyfluorfen + prodiamine) crop safety. The data contained in this report were generated to register uses of oxyfluorfen + prodiamine as over-the-top applications on and around ornamental horticulture plants. The rates tested were 2.75 (1X), 5.5 (2X) and 11.0 (4X) pounds active ingredient per acre (lb ai per acre).
Biathlon was applied to fifty-six (56) plant species or genera. Twenty-one (21) genera or species exhibited no or minimal transient injury in at least 3 trials. One species exhibited phytotoxicity or growth reduction in at least one trial at the 2X and/or 4X rate, but it may not affect the marketability of the crop. No species tested consistently exhibited significant phytotoxicity or growth reduction in more than one trial. Forty (40) species require further testing. Results are summarized at the species level, as there is some evidence that crop safety can differ at the varietal level. On the Biathlon label, Potentilla fruticosa appears twice: it may be used on the variety ‘Abbotwood’ but is not recommended on ‘Goldfinger’. More data is needed to establish the actual varietal sensitivities within Potentilla fruticosa, and identify other species with the same difficulty. We recommend Betula nigra, Camelia japonica, Chasmantium latifolium, Dasiphora fruticosa, Dryopteris erythrosora, Lantana camara, Quercus rubra, Rosmarinus officinalis, Rudbeckia spp., Salvia nemorosa, and Sedum spp. be added to the Biathlon label along with 13 additional varieties of species already listed in the label.