Hydrogen cyanamide is a plant growth regulator widely used in the kiwifruit industry to promote the growth of shoots, or ‘bud break’, in a controlled manner. Hydrogen cyanamide is the active ingredient in products such as Hi-Cane.

EPA Reassessment

The EPA is reassessing the use of hydrogen cyanamide. This is because the EPA determined that:

  • Risks to bystanders were above the level of concern, but this risk can be mitigated through the use of buffer zones
  • Risks to operators using Hi-Cane were above the level of concern. These risks could not be mitigated even with prescribed, modified, and additional controls, or considering the lowest current label application rates. Overall, without further refinements, the risks are above the level of concern for operators
  • Risks to the aquatic environment, non-target plants, pollinators, and non-target arthropods as well as chronic risks to birds were determined to be above the level of concern. Risks to these receptors can be mitigated through the use of buffer zones, restrictions on application rate and timing, and prohibiting application when bees are present.
  • Acute risks to birds were determined to be above the level of concern and cannot be mitigated even with the prescribed, modified, and additional controls.

The EPA has provided a number of recommendations:

  • Current approvals for hydrogen cyanamide be declined, and the substance banned
  • Hi-Cane to be phased out over five years with tighter controls taking immediate effect after the final decision.
  • Introduction of buffer zones
  • Update hazard classifications to:
    • Classify the soluble concentrate as skin and eye corrosive, rather than an irritant
    • Include a carcinogenicity classification
    • Change the specific target organ toxicity classification (from Category 1 to 2)
    • Classify as hazardous to soil organisms
    • Lowest possible application rates (Hi-Cane application rate is not restricted in New Zealand. The EPA is proposing that a maximum application rate of 25 kg ai/ha is set)
    • Maximum wind speed of between 3 km/h and 20 km/h. (Not to be applied when wind speeds are less than 3 km/hr or more than 20 km/hr as measured at the application site). If spraying under 3km, then drift can travel for a lot further
    • Update labelling and packaging requirements

The full EPA reassessment can be found here

The EPA recommended a number of controls, as follows:

Proposed bystander buffer zones:

Note: ai means active ingredient

Note: The EPA are proposing the introduction of a maximum application rate of 25kg of ai per hectare. This means at 6% you can safely spray up to a volume of around 750L per hectare. Growers wishing to apply at 7% will be restricted to around 650L per hectare.

Proposed buffer zones to protect the aquatic environment (waterways)

Aquatic environment

In the risk assessment, the term aquatic environment is used to encompass any area of water that contains any of the aquatic species assessed (fish, aquatic invertebrates, aquatic plants/algae).

In terms of the proposed buffer zones, while the draft controls mention the aquatic environment, the tables set out particular distances to a downwind or downslope water body.

The EPA definition of a water body:

Water body – Includes all-natural and modified/artificial watercourses such as reservoirs, irrigation canals, water-supply races, canals for the supply of water for electricity generation or farm drainage, ditches, streams, rivers, ponds and lakes. For clarity, it excludes fully covered pipes, tanks or other enclosed structures, puddles or groundwater.

Watercourse or Waterway – Includes every river, stream, passage, and channel on or under the ground, whether natural or not, through which water flows, whether continuously or intermittently.

Proposed downwind buffer zones to protect non-target plants

In the risk assessment, the term “non-target plants” means plants that are not the intended pesticide target.

In terms of the proposed buffer zone distances for non-target plants, these are set in conjunction with clause 51 of the Hazardous Property Controls Notice 2017.

Application method restrictions

This substance must be applied using ground based methods only. This substance must not be applied when windspeeds are less than 3km/h or more than 20km/h as measured at the application site.

Use restrictions

The use of this substance is limited to the period from 15th July to 1st September.

Additional information requirements

The following shall appear on hydrogen cyanamide documentation:

“Do not consume alcohol the day before or up to seven days after application. In combination with alcohol, a severe temporary reaction known as “cyanamide flush” may be produced. Symptoms of cyanamide flush includes skin flushing, dizziness, headache, shortness of breath and a rapid pulse.”

NZKGI Hi-Cane submission

NZKGI lodged a submission on the 17th of December 2021 which can be found here. All other submissions can be found here.

The EPA prepared a Submissions Analysis Report which can be found here. The EPA received 202 submissions. A total of 78 submitters supported the application to ban Hi-Cane, and 117 opposed it. Three submitters indicated that they neither supported nor opposed the application. The position of four submitters could not be determined.

Submitters raised concerns about community exposure during spray season, water contamination, off-target effects on birds, eels, dogs, and other animals, and human health effects related to exposure. People questioned why kiwifruit is grown in areas where hydrogen cyanamide is required and the ability of the industry to self-regulate when it comes to spraying hydrogen cyanamide. The safety of those who work with hydrogen cyanamide on orchards was also discussed in detail. The EPA also heard from many orchard owners and industry workers who proposed hydrogen cyanamide as the only cost-effective option available to them, stating that without it, many orchards would become unprofitable.

Science Reports

NZKGI recently submitted two reports to the EPA:

  • The National Wellbeing Impacts of the Removal of Hydrogen Cyanamide – TDB Advisory, and,
  • Assessment of Worker Exposure to Cyanamide During Vine Spraying – HaS Expertise.

Zespri submitted the following reports:

  • Exposure study on kiwifruit orchard workers spraying hydrogen cyanamide in the Bay of Plenty, New Zealand to assess the level of systemic exposure – Air Matters,
  • Hydrogen Cyanamide Exposure Study Supplementary Report Letter 22227 – Air Matters, and,
  • Bird Use of Kiwifruit Orchards Around the Time of Application of Hydrogen Cyanamide – Wildlands.

These reports can be found on the EPA website.  NZKGI and Zespri are hopeful that these reports will result in a more realistic assessment of the risk of HC based on New Zealand conditions and that this will be reflected in the Update Science Report and Memorandum.

What next?

The hearing is currently due to commence on 6 March 2023. NZKGI notes that this tight timeframe coincides with the holiday season.  For that reason, NZKGI has commissioned experts to start preparing evidence now.

Set of Hi-Cane controls

Many submitters who opposed the ban stated that HC is safe to use with workable and appropriate controls including the use of shelter and buffer zones of varying distances. NZKGI is of the view that it would be beneficial if an industry agreed set of HC controls could be proposed at the hearing.

NZKGI is working on this and will release information for feedback as it becomes available.

Hi-Cane versus no Hi-Cane and Hi-Cane alternatives

Several growers have contacted NZKGI with concerns that NZKGI’s submission focussed on the effects of losing Hi-Cane for green kiwifruit and may have understated the need for Hi-Cane for gold.  Other growers are saying that without Hi-Cane they would be out of business this season.  This has largely been driven by the warm winter experienced this season and growers are concerned about the prospect of increasingly warmer winters with climate change.

Growers have also contacted NZKGI to make them aware of the unsatisfactory results they have seen on their orchards where they have used Hi-Cane alternatives.

NZKGI is collecting photographic evidence that Growers have supplied and will be analysing fruit data in December so that it can make these points very clearly to the DMC. If you have information that would be useful, please send it through.

Social impact assessment (SIA)

The DMC noted that the information available to them provided diverse commentary on the current social impacts of hydrogen cyanamide use and potential social impacts if hydrogen cyanamide was no longer available. The DMC considered that the available information on social impacts was incomplete and that an independent report would provide a more comprehensive investigation of these aspects. Therefore, the DMC requested that EPA staff investigate options for an independent social impact assessment report to aid them in their decision-making and have since commissioned Sapere to prepare a report.

Sapere has contacted a number of submitters including NZKGI to be interviewed for the SIA.

We want to hear from you!

NZKGI acts as the representatives of Growers and it is important that the information being relayed reflects the views of Growers. What we strive for is the best outcome for growers and we can’t do that if we don’t talk to you. Your opinions help drive our response. Get in touch here