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Herbicide Trial Results

Hopefully, everyone has had a relaxing Christmas and New year period and enjoying some well earnt down time at the moment.

We thought this would be a good time to update everyone on a few of the trials we have been conducting over the last couple of months. As explained in the latest blog we have a great focus on offering a leading agronomy service and the recent purchase of our hand-boom has come at a great time with the late season rains and plenty of weeds.

Trial Aim:

Evaluate the value of adding a range of “spikes” to a standard Glyphosate + Amine tank mix for control of large Sow thistle (Milk Thistle). As well as assessing the difference between using Kombo (Surfactant/Drift management/PH reduction ) and Tribute (oil/wetter combination).

All trails were sprayed at 70lts/ha water rate.

Untreated Photo | Untreated Sow Thistle | Hand Boom Setup

We were interested to see the difference adding a range of ‘spikes’ to the tank mixes, how that would impact control as well as what difference changing adjuvant would make. Also a key point was taking into account the difference in cost of each herbicide mix.

These were big weeds with established root systems and moisture underneath so the final assessment was taken 35DAA (Days after application) to ensure we captured any regrowth.

Sledge + Kombo 7DAA | Gly + Amine + Kombo 7DAA | Fluroxypyr + Tribute 7DAA

7DAA, as expected the mixes with Sledge, Amine and Fluroxypyr (Starane) you will not see visual signs of brown down in the first two weeks after application. These are slow products so take that into account when using them.

Terrador + Kombo 7DAA | Terrador + Tribute 7DAA

7DAA, Terrador is a new product that Nufarm will be releasing in early 2021, it will be a group G knockdown spike with great burn down. As with most group G's they work much better with a oil based adjuvant and high water rates. It can be seen in the above photos the difference in just 7DAA how much quicker the brown down is compared to the other treatments also note the increased efficiency with Tribute over Kombo. We will be doing more work with Terrador closer too seeding, it is very strong on marshmallow, Medic and Grasses. (Watch this space)

Sharpen + Kombo 7DAA | Sharpen + Tribute 7DAA

Once again here we are showing the value of getting your adjuvant selection right with group G knockdown spikes. Above is Sharpen, another group G demonstrating the importance of using an oil based adjuvant.

Sledge + Kombo 35DAA | Sledge + Tribute 35DAA

35DAA, Treatments containing Sledge showed that changing to Tribute increased control however it would not be a acceptable level of control on these larger Sow Thistles. If you were able to graze the paddock after the 7day WHP that would potentially aid in control, however with the cost of Sledge this would not be my first option.

Gly + Amine + Kombo 35DAA | Gly + Amine + Tribute 35DAA | Terrador + Tribute 35DAA

35DAA, Demonstrating how changing to Tribute from Kombo on these bigger weeds can be very important when up against big weeds and summer weather conditions. As I have stated before grazing would potentially help control and as most of you would be aware using 2,4-D Amine works well in a stock grazing system.


. Make sure you are matching the correct adjuvant/surfactant if adding particular spike product's - especially your group G's.

. Your group G spikes (Terrador, Sharpen, Hammer etc) will give great burndown results early, however watch for regrowth on bigger weeds and having a robust rate of Glyphosate is a must with these products on big weeds.

. Whenever using Fluroxypyr (Starane) expect slow results, do not expect quick brown down in first two weeks.

. Sledge did not give satisfactory results controlling these large Sow Thistle's. All other brews did provided control at the 35DAA inspection, however what must be taken into account is these brews ranged $11.50/ha-$19.50/ha showing spending more is not always the first option.

. "More of the same" is proving to be just as good as adding some of these "spikes" into our tank mixes especially over the summer period. The most cost effective treatment in this trail was robust rates of Glyphosate 450 + Amine 625 + Tribute.

. Our staple products like Glyphosate and 2/4-D are doing most the heavy lifting, keeping our rates up and robust on the first pass is key and we should only be adding a spike in particular situations eg. Garlon for melons, Fluroxypyr for SLNS.

. "There is more than one way to skin a cat" with summer spraying there is many variables and we were able to get good weed control with many of the selected brews. However cost/ha and weather conditions dust, heat etc will come into discussion when finding the best recommendation in each situation.

. Kombo is still a great product for summer spraying, however when up against big established plants Tribute (Oil concentrate with >15%surfactant) will help reduce spray droplet evaporation as well as still having the spreading value of the surfactant.

Keep an eye out for another local trial update next week!

As always, please feel free to ring us to discuss any of your specific issues, questions or you are looking for more detail, In the meantime enjoy the beach.

Kevin Dart - 0474 272 577

Troy Maitland - 0499 272 544

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