What herbicide can be used within 1-5 metres of a water body, and at what rate?

• A. Atrazine, 3.0 kg/ha.
• B. Triclopyr, with a maximum application rate of 1.92 kg active ingredient per hectare.
• C. Glyphosate, with 2.0 kg/ha.
• D. 2,4-D, 0.5 kg/ha.

Answer: (B)

The essential idea is that how close you can apply a herbicide to a water body—and at what rate—depends entirely on what the product’s label allows. For a given proximity to water, only certain products have approval to be used that close, and with a maximum rate you must not exceed.

Triclopyr has a label that allows application within 1–5 metres of a water body, provided you stay at or below the maximum rate of 1.92 kg of active ingredient per hectare. This combination of the specified proximity and the rate limit makes it the only option that fits the stated requirement.

The other herbicides do not meet both conditions for this proximity and rate. Their labels either do not permit application that close to water, or the allowed rate at that close distance would be higher or lower than the specified 1.92 kg ai/ha, or the proximity guidance differs. Always confirm with the current product label, since label specifics govern these near-water applications and can change.