GEORGE NEWS - The contentious herbicide glyphosate was present in a water sample that the Garden Route Dam Action Group (Gardag) collected and had tested late last year.

"We had the dam water tested for glyphosate after someone said they saw the Kariba weed in the dam being sprayed in 2021."

"The levels of glyphosate were low, but it is present. What is disturbing, is that we found the municipality spraying all the pipeline routes in the Meul River wetland too," said Gardag chairperson Desireé du Preez.

A local aquatic expert who spoke anonymously to George Herald said spraying with herbicides registered for use on aquatic weeds does form an acceptable part of an integrated pest management plan. "But the parameters, for example product, dosage, timing, location, etc, should be established to prevent negative impacts to the environment and drinking water resource. The only herbicide registered for use against Kariba weed is Kilomax, which contains glyphosate."

The Centre for Biological Control at Rhodes University assisted in multiple releases of weevils at the dam, and to set up a weevil rearing station at the Garden Route Botanical Garden which has since been discontinued.

George Municipality said it submitted an eradication plan to the Department of Forestry, Fisheries and Environment (DFEE) in March 2021. Kariba weed is the only aquatic invasive species listed in the plan and the control method is chemical control by use of glyphosate. The municipality however used biological control, manual removal and spraying (undertaken once) with environmentally friendly materials suggested by a registered aquatic specialist, due to the size of the then-infestation. The most recent biological control was done in February 2022. The product used for the spraying in 2021 was Kilomax.

According to the municipality, Kariba weed is currently under control in the Kat River. Weevils are not being reared now and should there be a need for further biocontrol, weevils will be sourced from Rhodes University.

Sidewalks and gutters

The municipality uses Suburb to spray sidewalks and gutters. This herbicide has glyphosate and terbuthylazine as active ingredients. It is registered under the Fertilisers, Farm Feeds, Agricultural Remedies and Stock Remedies Act, 1947 (Act No. 36 of 1947) under the number L7518 Act /Wet No. 36 of/van 1947. Suburb is categorised as Group III in terms of hazards, meaning that it must be used carefully and with protective clothing. This act is regulated by DFFE.

The Civil Engineering Department uses the product Piranha Dry [the active ingredient is glyphosate, as glyphosate ammonium salt] to control overgrown pipeline servitudes, which is safe to the environment when diluted to the specified dosage/application, says the municipality. "Spraying is undertaken to assist in clearing access so that blocked manholes can be visually observed and attended to. The operational personnel are well trained to use/apply the herbicide."

The municipal herbicide team consists of a supervisor, leader workers and small plant operators. "The herbicide is mixed according to the mixing ratios on the herbicide label by a leader worker or supervisor in the herbicide tanks that are fitted in the vehicles, prior to going out to spray. The team is provided with PPE (personal protective equipment) suitable for herbicide. The small plant operators spray from the back of the vehicle under the supervision of the leader worker or supervisor. Inhouse refresher training is held annually with the last training conducted in January 2023 by the service provider that supplies the municipality with the herbicide."

'Reducing glyphosate usage'

"Most systemic herbicides contain glyphosate and George Municipality is considering (1) actively reducing glyphosate usage over time and (2) substituting glyphosate with alternative chemistry in sensitive areas. To this end George Municipality is already reducing its glyphosate usage by using products such as Suburb with low glyphosate content (180g/l) and extended residual control

(3 - 4 months) so as to reduce the need for frequent spraying."

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