A spray that helps kiwifruit to fruit at the same time is due to get its safety reassessed again. Farah Hancock reports.
How do you get an orchard of kiwifruit to fruit at the same time? One way is to spray a hydrogen cyanamide in August.
The chemical, most commonly used in a spray called Hi-Cane, fakes the effect of a good winter frost for the vines, signalling it’s time for them to get flowers under way.
Fake frost means kiwifruit orchards can be planted in warmer places where fruiting may not happen – or at least not as uniformly or abundantly – without the chemical helper.
It’s used from Northland to the Bay of Plenty and even in Nelson, where our southern-most orchards lie.
Hydrogen cyanamide products are currently up for reassessment by the Environmental Protection Authority (EPA). Depending on the outcome, there’s a chance the rules around its usage may change, or it could even be banned as it is in Europe.
In 2018, kiwifruit’s export revenue was $1.8 billion, representing 32 percent of New Zealand’s total horticultural export revenue.
NZ Kiwifruit Growers Inc CEO Nikki Johnson said the majority of New Zealand’s almost 3000 orchards will be using the chemical. Its ability to compress the flowering season saves labour costs and ensures all fruit picked are uniformly ripe. Even in places with cooler winters like Nelson it’s used for this reason. Instead of having an orchard with fruit ripening over three or four weeks, you have ripe fruit all in the same week.
Removing the chemical from growers’ tool boxes could render many parts of the country unsuitable for growing the iconic export crop.
Research by NIWA published in 2017 mapped the country for where the green Hayward kiwifruit could be grown based on temperature with and without the use of the chemical. Climate change effects were thrown into the equation.
Lead author Dr Andrew Tait said as air temperatures increased there was the likelihood of more mild winters.
“This could put significant stress on the kiwifruit industry in the Te Puke area, particularly if hydrogen cyanamide is banned.”
While his research mainly focused on Te Puke, he did map the entire country. Without hydrogen cyanamide, much of the north has been ranked as ‘poor’ for growing since 1970 and becomes marginally worse by 2030 based on temperature.
There’s good reason to make a model such as this. The chemical helper has a catch. While it might be a convenient substance for kiwifruit growers, it’s not particularly nice.
It’s toxic to humans, mammals, bees, aquatic organisms, and possibly birds.
The spray is banned in Europe for forcing flowering, but is approved as a ‘biocidal’ product. This means it can be used if the purpose is to kill something. It’s approved in Australia, the United States and Canada.
Kerikeri resident John Levers paid for part of the reassessment application himself, putting $1400 toward the cost. The remainder is being covered by the EPA.
He has been raising concerns about the spray after a neighbour sprayed his orchard with the chemical in 2018 without first informing him.
The day after, his two labradors were playing on his own property, rolling around on grass.
“You know how dogs lick themselves, they both nearly died.”
The same day he found two dead eels in a stream between the properties and a dead family of nine ducks in one of his ponds.
In his region, some orchards butt up to roads and streams meaning that without high screens erected during spraying, drift is a risk.
“Kids have to walk past these orchards while spraying to go to school.”
The chemical’s effect on people can vary. Ingesting too much can be fatal, contact with skin or eyes can be an irritant, repeated exposure may cause reproductive damage.
There’s also what’s known as cyanamide flush, which affects people who drink alcohol 24 hours before or seven days after using the spray. As well as causing skin to be flushed, dizziness, headaches and shortness of breath can be experienced.
His application for reassessment is based on new information available since the chemical was last assessed by the EPA in 2006.
This information includes a European Food Safety Authority peer review conclusions report.
Part of the report investigated what’s known as an acceptable operator exposure level (AOEL). This is the maximum amount of exposure someone using the spray can be exposed to without ill effects. It’s then estimated how much exposure a worker may be subject to when preparing and spraying.
The European document notes:
“Tractor-mounted application was considered in grapevine and kiwifruit. The operator exposure estimates were above the AOEL (6433 percent ) even if personal protective equipment (PPE) is used (gloves and half-mask (filter A1P2) during mixing/loading, and gloves, coveralls, rubber boots, and hood and visor during spray application).”
Spot checks to continue
WorkSafe’s chief inspector Darren Handforth said 22 workplace assessment spot checks were completed last year to determine if rules around Hi-Cane were being followed.
Twenty-one enforcement actions were taken as a result of the 22 visits. There are around 2600 kiwifruit growers in New Zealand.
“WorkSafe plans to carry out spot checks later this year; however, this will be highly dependent on any ongoing impacts of Covid-19, and the EPA’s decision on the upcoming reassessment of the use of Hi-Cane in New Zealand.”
Who is the regulator?
While the EPA can decide what chemicals are allowed for use in New Zealand and what the rules are for using them, it’s not a watchdog in work places like orchards.
Where workers are involved, this responsibility falls to WorkSafe.
In cases where the public or the environment are impacted, such as through spray drift, regional councils play a part through their respective air plans.
Given its fleeting nature, catching instances where spray drift has occurred is tricky.
NZKGI’s Johnson suggests the public report issues immediately and, where safe, photographs or video of it occurring.
The search for alternatives
Johnson said the industry had been looking for something else for some time as they’re aware of the concerns about the product.
“There’s been quite a lot of money spent and looking for alternatives.”
The only one emerging as an option is a product called Advance Gold, which is more expensive and trickier to use, said Johnson.
“It’s quite time-sensitive. You have to get application absolutely right in terms of the timing of the plant, and where it is at in its development cycle or it won’t work.”
While alternatives are a short-term goal, she said a kiwifruit breeding programme was looking for varieties that can survive in different climate conditions as a longer-term solution.
There are other ways the industry is trying to reduce risks.
The organisation is requiring all its growers to use a new type of spray nozzle to minimise spray drift. She said growers also needed to make a spray plan identifying potential risks like neighbours or waterways.
The orchard is also required by law to contact any neighbours who may be affected.
This was normally the trickiest thing, said Johnson, as people sometimes shift homes or change phone numbers.
She encourages people with complaints to get in touch with the organisation. Last year there were 13 complaints during the spraying season. Most were due to a lack of notification, one was related to spray drift and two related to spraying in windy conditions. All complaints were followed up by NZKGI.
Growers with complaints made against them are audited more thoroughly the following year and record of continued complaints could lead to monetary penalty.
She said this had not happened before.
In the 2006 EPA reassessment for Hi-Cane, the NZKGI submission asked for the product to be able to be used with no additional controls.
Johnson said the organisation got an independent assessment of the toxicology risks, which it shared with the EPA.
“It’s the independent assessor’s view that it is possible to manage the risks to both environmental and human health through the application of measures and some of those measures are additional to what is currently required.”
One of the measures is for the use of the new spray nozzles to become one of the regulatory controls for the use of the chemical as well as some changes to PPE.
An EPA spokesperson said the reassessment application was being worked on, and public submissions would be taken at a future stage.
There is no set time frame for reassessments as some are more complex than others.