Callisto Trial

Does the higher rate of Callisto alone provide equivalent efficacy and crop safety to the tank mixes of Callisto and partner herbicides?
How does the efficacy and crop safety of various rates of Callisto compare to triasulfuron?

Ogilvie, WA, 2018

Summary

This trial was established near Ogilvie, Western Australiaon the 3rd of June 2018. The major target species being (1) WildRadish and (2) Capeweed. All tank-mix partners improved final efficacy by10-14% except for Boxer Gold which seemed to have reduced efficacy by ~5%. Suggestingantagonism between Callisto and S-Metolachlor?

This site was deep ripped in January 2018 creating an unevenseedbed resulting in unideal seed and chemical placement. As a consequence, low-moderatelevels of phyto-toxicity were observed from all Callisto treatments (~25%) withtankmix partners Trifluralin, Sakura and Arcade increasing phyto up to ~35%.The observed crop effect was transient with all symptoms disappearing by the 86DAT assessment.

In this trial we didn’t observe a rate response from the low- high rate of Callisto with all achieving a final control rating of ~80% +/-2%. Compared with Triasulfuron which achieved a 61% final control rating.

Control ratings show 10-15% higher control in theTriasulfuron treated plots compared with the weed count results. This can beattributed to the fact that the radish that survived in the Triasulfurontreated plots were larger and unhindered.

Methodology

Treatment List

Experimental Design

Site, Crop and Application Details

Assessment Methods

Data Analysis

All data analysis in this report was conducted using Microsoft Excel. Simple means, analysis of variance and the student t-test were used to determine statistical significance using the least significant difference method with a 95% confidence interval.

Results

Visual Control Ratings

Figure 1: The % control of radish at each assessment date. Showing Standard Error and the LSD for each weed species. The 86 DAT assessment was left out as it was done by Andrew Cripps. His assessment shows the same trends but with different quantification. See combined results in Fig. 3.

At the 23 DAT assessment there is a rateresponse from the 100mL to 200mL Callisto, giving ~10% better control of both weedspecies between the bottom and top rate.
All tank-mix partners seemed to improve efficacyof radish except for Boxer Gold.
Callisto + Sakura and Callisto + Avadex Xtrasignificantly improved control of radish compared with the 100mL & 150mLrate of Callisto alone at the 23 DAT assessment.
All rates of Callisto performed better thanLogran with the top rate of Callisto significantly better at the 23 DATassessment.
Gallery started strong but dropped offsignificantly after the 23 DAT assessment.

Figure 2: The % control of capeweed at 23 & 45 DAT. Showing the Standard Error and LSD for each weed species. Capeweed ratings were not performed on the 86 & 98 DAT assessments as the radish had out competed the capeweed making it difficult to rate. See images in the appendix.

A rate response can be seen at both assessmentdates between the top and bottom rates of Callisto.
There is a slight gain in efficacy ~5% whenCallisto is tank mixed with Trifluralin, Sakura and Avadex Xtra.
The tank mix with Boxer Gold and Arcade showed aslight decrease in efficacy.
At the 45 DAT assessment the top rate ofCallisto and synergistic tank mix partners provided significantly bettercontrol than Logran.

Figure 3: The combined control of radish and capeweed for each assessment date. Note the 86 DAT assessment showing radical differences in ratings. This is as a result of a different assessor – Andrew Cripps.

Weed Counts – 45 DAT

Radish per m2 vs. % control

Figure 4: Weed counts and % control of radish.

The radish weed counts show that Logran has achieved similar control to the Callisto treatments. Different to what the visual control ratings say. Note that the surviving radish in the Logran plots had significant size over the Callisto treatments. See photos in appendix.

Capeweed per m2 vs. % control

Figure 5: Weed counts and % control of capeweed.

Visual Phyto Rating

Figure 6: Crop phytotoxicity at 23 & 45 DAT

Phytotoxicity was visible in all Callisto treatments. With the site deep-ripped, seed placement was variable. Where seed was placed improperly, we saw yellowing and bleaching of the crop. However, the damage was transient with no visual reduction in vigour noticeable at later assessments. See images in the appendix of observed phyto.

Establishment Counts

No significant difference in establishment between treatments.

Conclusion

In this trial, Callisto performed extremely well when placedunder high radish pressure and unideal seeding conditions. By the 2ndof August, at the Independent Rural field day, the grower had sprayed twobroadleaf herbicides to achieve the same results as the Callisto treatments.

Callisto will bring a 4th group H option into play, competing directly with Velocity, Talinor and Frequency. However, Callisto is unique in that it is used in the pre-emergent space. With group B, I and F resistance developing in radish populations around northern ag zone, timing of application and the correct choice of product is critical. For growers with large programs or known dirty paddocks, Callisto provides flexibility for growers as they will only need to get back over that country later than they otherwise would (5-6 weeks post sowing), improving the odds of correct timing and reducing the pressure on the older generic options (F I C).

Appendices

Rainfall

Photos

Figure 8: Late visual comparison of the 200mL Callisto Vs. Untreated. Note vigour of the radish, making it difficult to assess capeweed beyond 45 DAT.

Figure 9: Picture of the damage caused by Callisto. Left is a treatment with Trifluralin and Gallery. Right a treatment with Callsito and Sakura.

Figure 10: Picture showing the effect of Callisto on small radish. Callisto treatments holding the radish back, whereas in the Logran treatments the radish was more vigorous. See Fig. 11

See below Dropbox link to photos and videos at each assessment date:

https://www.dropbox.com/sh/ou4zwu6zi175hjs/AAB6pEdjoTNKHU7McxOnOi3xa?dl=0