Have you heard of laser-, steam-, hot water-, hot foam-, infrared-, electrical-, or electrothermal weeding? While rarely used in New Zealand forest nurseries, these globally applied, non-chemical precision weed control methods are gaining attention, especially in countries with strict chemical residue regulations. The Netherlands lead in developing such technologies.

Insights from a global technology review and interviews with ten New Zealand forest nurseries, led by the BSI, are guiding the Precision Silviculture Programme to evaluate potential advanced weed control methods for trial locally.

Managers from six major bareroot nurseries reported heavy reliance on broadcast herbicides—mainly oxyfluorfen—alongside manual weeding. Although effective and affordable, concerns over herbicide resistance and soil health remain, with weed management costs ranging from $3,000 to $20,000 per hectare annually.

Currently, precision weed control is mostly manual, with only one nursery using a GPS-guided hooded sprayer. There is growing interest in innovative solutions like laser weeding, AI-driven smart sprayers, and non-chemical methods such as hot foam, which could reduce chemical improve efficacy in dense plantings.

Challenges to adoption include high planting densities, early growth sensitivity, uneven terrain, and limited engineering support. New technologies must integrate smoothly and maintain productivity. Demonstration trials and strong business cases are vital for successful uptake. Laser weeding and camera-operated sprayers are seen as the most promising. The next project phase will shortlist technologies for local trials.

“We could probably reduce our chemical use by about 60 to 70% through precision targeted spraying,” one nursery manager noted, underscoring the environmental and operational advantages.