The future of weed control in hardy nursery stock

AHDB’s Wayne Brough spoke to David Talbot of ADAS about the latest developments in weed control solutions for hardy nursery stock

Developing and maintaining year-round chemical weed control programmes for container-grown hardy nursery stock has become increasingly challenging due to the limited range of residual herbicides available to the sector.  Restrictions on many of the available products also limits the timing or number of applications of many of the remaining available residual herbicides.  However there is a new residual herbicide on the horizon that has potential for use in nursery stock production (within both field- and container-grown production systems) and has been included (as HDC H46) in recent AHDB funded trials; the company behind this product is working to secure either a label approval or EAMU for the sector.  New product development and registration takes time though, so this new product may still be several years away from being commercially available (assuming it meets all the necessary regulatory requirements).

Meanwhile, Sencorex Flow (metribuzin) has been assessed for crop safety as a winter treatment in trials this year and showed promising crop safety on several of the container-grown species tested, presenting hope of wider use in container-grown production.

The disruption caused on production nurseries by Covid-19 this year has resulted in many container-grown nurseries carrying a higher burden of weeds than normal.  Recent losses of effective contact acting herbicides (such as diquat) have made the control of established annual weed populations increasingly difficult. However, there may be alternative contacting herbicide options for weed control in the pipeline, though more work is required to determine the detail of their use.

Without any doubt the future of weed control on container nurseries now demands an holistic approach, utilising all available control methods - physical, cultural and chemical. With fewer options to control weeds chemically, every effort must be made to prevent weeds setting seed and thus spreading within container-grown nursery production systems.

To bring all the options together into some sort of overall practical context, an event is being planned for summer 2021 (delayed from 2020) to demonstrate the crop safety of residual herbicides in container-grown crop production combined with European experiences of various pot toppers and mulches. Watch this space for further detail!

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