Spraying Tauranga City's grassed areas for Onehunga Weed may be limited in future to public playing fields where people wear shoes, because of the weed sprays' increasing toxicity.

The prickly pest is increasingly resistant to Tordon and Versatil, but the staff recommendation they be replaced by Image is opposed by the council's Toxic Agri-chemical Advisory Forum.

The spray Image is a combination of three ingredients, one of which is not approved for use in Europe, says TAAF spokesperson Jodie Brunning at the city council's Environment Committee this week.

'For example the EPA has recently denied this (Ioxynil) as a product that can be on sale to the public because of undue exposure to toddlers,” says Jodie.

'The persistence of the active ingredients is particularly concerning because our agrichemical policy only allows for signage for up to two days. These chemicals persist for 10 to 60 days.

'Which is why if we are to use it on active sports fields, it's with shoes on.”

Currently Tordon Gold, Tordon Brushkiller, Versatil are sprayed in Tauranga city's active and passive reserves. TAAF recommends limiting spraying to active (bookable) sports fields, with use restricted to once per year in active reserves, and that they are not used mixed with any other Tordon product, Versatil or Image within that 12 month period.

And that signage recommending footwear is worn in places of frequent agrichemical use.

The recommendations are the consequence of three issues - the increased toxicity of the potential replacement Onehunga herbicide Image - particularly to children; the risk of future resistance to the replacement herbicide is extremely likely and that efficacy must be protected now; and with knowledge that the herbicide Image has active ingredients that persistent beyond the 48 hours city council warning signs are displayed.

The ‘creeping toxicity' of using more and more powerful chemicals to knock down increasingly resistant weeds is a public health concern, says Jodie.

'TAAF consider it is timely that council understand that creeping toxicity and the risk this involves is not in the public interest.”

Which is why TAAF is recommending all passive reserves, including 'key destinations' like Memorial Park, transition to spray free reserves.

TAAF also wants all active reserves with a more intensive spray regimes display signs recommending footwear be used at all times, and links (Q code) to the TCC webpage advising of the agrichemicals used seasonally.

TAAF reports to elected members and their recommendations were omitted from the staff report. The committee has called for council staff to look at the TAAF proposals and report back at the April meeting.

Speaking after the meeting committee chairman Steve Morris says they want to hear from staff what the consequences would be if they stopped spraying Onehunga weed.

'I think there would be a bit of push-back or back lash from the community on that,” says Steve.