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Prnum Pesticide(MFG) Commodity (Crop Group) Category (Code) EPA Status 13642 + PYRAFLUFEN-ETHYL NAI ONION (DRY BULB) (03-07A = ONION, BULB SUBGROUP) E/CS DATA ON-GOING (03G) Reasons for need: Annual weeds; probably loss of Dacthal and dire need for alternative herbicides for onion:06/23; NY/Dry bulb onions lack significant chemical tools for the management of emerged weeds (which are especially competitive in young onions). The addition of an active ingredient could enhance the diversity and flexibility of control programs:08/23 Efficacy/Crop Safety (E/CS) Data Required: MFG is concerned with efficacy and phytotoxicity and requires at least 6 E/CS trials in the following states CA(1), PNW (2), S. TX (1), GA(1), NY (1):09/23 E/CS Research Comments: PER THE 2024 PERFORMANCE PROTOCOL: TESTING ET HERBICIDE FOR PERFORMANCE AND CROP SAFETY ON DRY BULB ONION; TEST 5 RATES OF ET HERBICIDE/DEFOLIANT (0.0016, 0.0033, 0.0045, 0.0065, 0.0089 LB AI/A + ADJUVANT WITH EACH RATE [SEE ET LABEL FOR ADJUVANT]) VS A STANDARD; ALL TRTS ARE APPLIED BROADCAST EARLY POSTEMERGENCE (EPOST) OVER 2-LF CROP, IN AT LEAST 10 GPA; EVALUATE WEED CONTROL, CROP INJURY AND CROP YIELD Comments: No tolerance established, but use is labeled in many crop groups, including 03-07A, based on ChemSAC decision that allows preplant use of pyraflufen to be considered as 'non-food' use: 6/23; EPA GREEN: 08/23; Mfg Supports as Potential, E/CS Data before Approval for Residue:09/23; E/CS ongoing, data required before approval for residue study 02/24/DRS; Field Res.Dir (FRD) Field ID# Field Data Track# Raw Data Data to MFG Performance Results & Comments Liu, Rui 24-WAP02 Fennimore, S. 23-CA-DMP RECD 5642.pdf 10/23 ET HERBICIDE/DEFOLIANT APPLED BROADCAST FOLIAR AT 1, 2 OR 4 FL/A (0.0016, 0.0033 OR 0.0065 LB AI/A) OVER 2-LF ‘GREAT WESTERN’ DRY BULB ONIONS GROWING IN A SANDY LOAM SOIL. AT 2, 7 AND 14 DAYS AFTER APPLICATION (DAA), CROP INJURY FROM ALL RATES RANGED FROM 26 TO 39. AT 22 DAA, INJURY FROM TWO LOWER RATES HAD DISSIPATED TO 10 AND 13%. WHEN COMPARED TO THE NON-TREATED, ET DID NOT REDUCE HENBIT OR TOTAL WEED DENSITIES. NO DIFFERENCES IN YIELD OR GRADES WEERE SEEN BETWEEN TREATMENTS. Felix, J. 24-ORP05 RECD 5838.pdf 10/24 ET Herbicide/Defoliant applied broadcast at 1, 2, 2.75, 4, or 5.5 fl oz/a (0.0016, 0.0033, 0.00445, 0.0065, or 0.00898 lb ai/a) over 2-3 leaf ‘Vaquero’ dry bulb onions seeded into a Owyhee silt loam. Pyraflufen caused 14 to 39% injury 8 days after application (DAA), with an apparent rate response. Injury ranged from 5 to 18% 22 DAA. Only the two highest pyraflufen rates caused injury significantly greater than the standard treatment, bromoxynil + oxyfluorfen. Injury from all treatments was gone by 40 DAA. Overall weed control through 15 DAA was similar across all herbicide treatments with one notable exception. Except for the lowest rate, pyraflufen treatments provided significantly greater common lambsquarters control than the standard treatment 8 DAA. No significant difference occurred between herbicide treatments for total weed counts and weed fresh weights 36 DAA, but there were substantial numeric differences between some of the pyraflufen treatments and the standard treatment for individual weeds. Onion yield by grades from pyraflufen was not different from the standard treatment. Fennimore, S. 24-CAP05 RECD 5849.pdf 11/24 ET Herbicide/Defoliant applied broadcast at 1, 2, 2.75, 4, or 5.5 fl oz/a (0.0016, 0.0033, 0.00445, 0.0065, or 0.00898 lb ai/a) over ‘Great Western’ bulb onions seeded into a sandy loam, when ~50% of onions were 2-lf stage. All rates of pyraflufen caused crop injury, with injury from the three higher rates being higher than the standard program through 87 days after application (DAA). At 7 DAA, the two higher rates were required to control hairy nightshade, burning nettle goosefoot and total weed control similar to the standard program. Shepards’ purse was not sufficiently controlled by any treatment 7 DAA. With the exception of lower dried weight of large bulbs from the two higher rates, pyraflufen did not impact onion yield or quality.