Winter Wheat Preliminary CoAXium Trial

Objective:                  

To evaluate the crop safety of Quizalofop herbicide in CoAXium winter wheat.

Personnel:                 

Clint Beiermann, James Berg, Phil Bruckner, Jessica Pavelka                     

Summary:

Twenty five winter wheat lines were evaluated for tolerance of Quizalofop herbicide, trade name Aggressor®. The study was planted on September 28, 2020 and managed under rainfed conditions (Table 1.) Aggressor herbicide was applied postemergence at a rate of 24 fl oz/A to wheat at Feekes 4 to Feekes 5 growth stages. This is a higher than labeled herbicide rate and was utilized to maximize crop injury in order to distinguish differences in tolerance between winter wheat lines.  

There were ten varieties that were under 20% injured from the Aggressor herbicide 35 days after POST treatment (DAP) (Table 2). They ranged from 5.8% for MTAX21198 to 19.1% for MTAX21200. Fourteen of the varieties were above 20% injury, ranging from 22.2% for MTAX21195 to 49.2% for MTAX21192. Winter wheat injury was generally higher 21 days after POST treatment and all lines showed signs of recovery by 35 days after POST treatment, with the exception of FourOsix. The variety FourOsix was not tolerant to Aggressor and the herbicide treatment caused mortality 35 days after POST treatment. Battle AX is a known CoAXium traited wheat variety, however it was significantly injured at 29.8% at 35 days after POST treatment. Experimental varieties that displayed more tolerance than Battle AX indicate that safer wheat varieties are being produced for use with CoAXium trait tolerance.

The average grain yield was 126.3 bu/A, with the lowest being 101.6 bu/A for MTAX21202 and the highest at 143.9 bu/A for MTAX21187. The average protein percentage was 11.6%, with the lowest at 10.5% for MTAX21189 and the highest at 13.1% for MTAX21202 (Table 3).