Post-emergent Herbicides for the Control of Wild Radish

Efficacy of pre-emergentherbicides on broadleaf weeds (Radish & Canola) in wheat.

Dumbleyung, WA, 2018

Summary

This trial was established in Dumbleyung onthe 30th of May 2018 to compare and demonstrate to the extendedDavid Gray network the efficacy of two new/pipeline products (Gallery &Callisto) and a new use pattern for Terrain. These products were compared tolocal standards Logran and Diuron.

Gallery (Isoxaben) is Group O chemistrytraditionally used in tree crops. It can be used IBS, PSPE or EPE providingextended residual control of various broadleaf weeds, (BLW) including resistantradish. Gallery has a 2-year plant back for Canola and other broadleaf crops,hence must be used with caution. In thistrial it was applied EPE (2-3 leaf crop stage) in a tankmix with Bromoxynilproviding season long control of BLW.

Callisto (Mesotrione) is Group H chemistrythat has been used in maize for a number of years. It can only be used IBS andprovides residual control of various BLW including resistant radishpopulations. Allowing cheaper older chemistry to be used post-emergent.

Terrain (Flumioxazin) is Group G chemistrythat has been used as a knockdown spike (@ 30g/Ha). A new use pattern has beendeveloped where Terrain is used as a spike in the pre-seeding knockdown at thehigher rate of 120g/Ha - giving extended residual control of BLW in wheat.

In this trial, Gallery and Callisto gave98% & 93% control respectively, both treatments did not require apost-emergent broadleaf herbicide. Terrain provided 73% control compared withthe 55% and 35% achieved by Diuron and Logran respectively.

Methodology

Herbicide Treatments

Trial design

Site, Crop and Application Details

Assessment Methods

Results

Establishment Counts

Figure 1: # of plants in 0.5m of paired row. Part of the trial had an outbreak of grassy weeds affected the counts in some of the treatments

Weed Counts (Radish)

Figure 2: # of radish count per entire plot. Calculated as a % control Vs. untreated.

% Control (132 DAT Ratings)

Figure 3: 132 DAT ratings of % control of Radish

Both Gallery and Callisto treatments performed excellently and did not require a post-emergent broadleaf herbicide. Terrain gave excellent control early but started to let go by the 86 DAT assessment. Logran initially gave respectable control and seemed to hold back the radish, however the radish grew through and the Logran treatment finished with a poor ~35% control.

Resistance Test

Conclusion

This trial effectively demonstrated the performance of new residual BLW herbicides for use in wheat. Each with their unique fit, mode of action (MOA) and application method/timing, offering growers various options to fit their specific needs and help combat resistant radish populations.

Appendix

Site Rainfall

Photos

Please follow Dropbox link below for photos at each assessment date:

https://www.dropbox.com/sh/r2oysgby934kinn/AABErYXFfGxce_AZ8IhA-TMYa?dl=0