Specticle Achieves Outstanding Results On Poa Annua In Recent Melbourne Golf Course Trials

In the last couple of years Specticle^® herbicide was introduced into the turf market with an entirely new mode of action from other pre-emergent herbicides.

Specticle has been in development in Australia for 10 years and was first registered in the USA in 2010. So it has a long history of research and use in turf management around the world.

As part of a commitment to further research Poa Annua management, two trials were established earlier this year in Melbourne.

Trial 1

Trial was started on a golf course with an existing Poa Annua population present in January (average population was 8%).

Trial 2

The second trial was on a golf course with no existing Poa Annua plants in January.

Treatments

Both trial sites received the same treatments. The Specticle treatments (in ml/ha) were;

1. Specticle 250ml in January
2. Specticle 125ml in January followed by 125ml in February
3. Specticle 250ml in February
4. Specticle 125ml in February followed by 125ml in March
5. Specticle 250ml in March
6. Specticle 125ml in March followed by 125ml in April

A competitor product was applied for comparison, with treatments including a label low and high-rate application, and application timings of January, February and March. All the herbicide treatments were compared to an untreated control treatment.

Assessments

Poa Annua populations and turf quality were 0, 2, 4, 6, 8 and 10 months after the start of the trial (at the time of writing this report the 10-month assessments had not yet been made).

Results

By the 8-month assessment in September the Poa Annua incidence in untreated plots had increased to 38% in Trial 1 and 15% in Trial 2.

In Trial 1 with the existing Poa Annua population present at the start of the trial the Specticle treatments have resulted in a change in the Poa Annua population ranging from a 4% increase to a 6% decrease when compared to the population in January. Four out of the six Specticle treatments actually have less Poa Annua now than they did in January. Specticle is known in some situations to have a post- emergent effect on Poa Annua. The Poa Annua population in all the competitor product treatments has increased compared to the population in January.

At 8 months in Trial 2 the average Poa Annua population across the Specticle treatments was 3% and 8% for the competitor product treatments.

In Trial 1 the turf quality at 8 months was significantly better in many of the Specticle treatments compared to the untreated and the competitor product treatments.

In Trial 2 there was no significance difference in turf quality at any assessment to date.

Discussion

Both trials confirm that Specticle will provide very effective long-term control of Poa annua. The latest assessment in Trial 1 at 8 months is showing an average -2% change in the Specticle treatments compared to +10% change in the competitor treatments. There has been evidence of some post-emergent activity of Specticle on Poa Annua which was already present when Trial 1 was established.

Interesting in Trial 2 Poa Annua did not become apparent until ay. The normal feeling is that Poa Annua germination occurs much earlier than this. It may be possible to delay pre-emergent herbicide application later in the season than has been practised normally, especially if there is some post-emergent activity from the herbicide like there is with Specticle.

The two trials have not shown difference in Poa Annua control from Specticle applications made at any time in the January to April window. Experience from the USA and more recently in Australia has confirmed that optimum timing of Specticle is when the peak germination of Poa Annua germination is occurring in autumn. This gives flexibility over competitor products which must be applied before germination has started.

In Trial 1 turf quality was significantly better from the Specticle treatments.

Always read the label for full directions on the use of turf protection products.

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