Barricade (Prodiamine) and Carbon Trader – for the Professional Nurseryman

Barricade (Prodiamine) and Carbon Trader – for the Professional Nurseryman

Recent research by Todd Layt of Ozbreed Pty Ltd has found that there is potential to greatly reduce hand weeding and keep plants greener in winter in Australian Nurseries

Many chemicals and other specialist products are widely used in the turf industry. Many of these can have major benefits for the nursery industry, but only if they are ultimately registered or trialled in the growing of plants.

Literature Review from USA:

• USA research shows Prodiamine moves less deeply in the soil or potting mix than Oryzalin.
• Both these chemicals are listed for most plants in the USA. Oryzalin is not listed for many ornamental grasses. Prodiamine OK on ornamental grasses.
• Prodiamine did not do so well on Broadleaf weeds in USA trials, but USA rates are low. Higher rates worked for Broadleaf weeds in Australian trials.

Summary of Research:

Prodiamine: used 30ml per 100 square metres with the following results:

• Broadleaf weeds were not stopped.
• Stopped most grass weeds.
• No harm to health of any plant.
• Weeds were more numerous in control.

Prodiamine: used 45ml per 100 square metres with the following results:

• Broadleaf weeds were reduced, but not totally eliminated.
• Stopped all grass weeds.
• No harm to health of any plant.
• Weeds were far more numerous in control.

Prodiamine: used 60ml per 100 square metres with the following results:

• Broadleaf weeds were totally eliminated.
• Stopped all grass weeds.
• No harm to health of any plant.
• Weeds were far more numerous in control.

Both the garden and container trials showed similar results, although it was noted that the second trial in the garden reduced weeds by more than in the containers. 3-4 months of control.

Soils in the garden were clay. Less drainage should keep more chemical near top of soil. Syngenta is looking at registering for ornamental pots, growing beds, and landscape plantings i.e plant plants then spray barricade over the top immediately.

Prolan (Oryzalin): used 45ml per 100 square metres with the following results:

• Broadleaf weeds reduced only slightly.
• Grass weeds reduced only slightly.
• No harm to health of any plant.
• Weeds were slightly more numerous in control.

Prolan (Oryzalin): used 80ml and 100ml per 100 square metres with the following results:

• Broadleaf weeds reduced mostly at 80ml and totally at 100ml.
• No harm to health of the plants in the trial.
• Later trial showed Agapanthus, Cordyline and grasses can be harmed by the Oryzalin at these rates.
• Spraying on the potting mix and not on the leaf of these plants seems to reduce injury greatly.
  Carbon Trader (CT) – turf plots were replicated with half sprayed with carbon trader, the other half a control. In summary plants and turf appeared in general to have overall better winter colour.
  Winter colour ratings and clippings were taken from the Kikuyu plots, and significant differences between the treated and not treated plots were found.

Gallery x Prodiamine: We have started research for mixing Gallery and Prodiamine. We are about to start trials and will have updates on this in the future.

Conclusion: The use of Prodiamine is widespread in the turf industry. This research shows that Prodiamine clearly reduces weed invasion without damage to most plants.

Registration of this product would greatly help Australian Nurseries. Syngenta has indicated that they will aim for registration of this product over the next 12 months. The industry should lobby for this to happen.

Further testing is needed for Oryzalin, but higher rates may find this product effective for weed control in nurseries. However the fact that it moves deeper in the potting mix according to literature needs to be tested and taken into account.

Carbon trader clearly shows benefit for many turf types in winter. Early indications show benefits for plant quality, but this assertion needs to be tested in a more controlled way.

It may be worth a try for nurseries wanting to improve the winter and early spring quality of their plants, particularly for those in colder areas.

To read the entire paper, download the pdf.

Nurseries learning from the turf industry | 570KB