Long periods of balmy weather means the likes of Hugh Rose can plant a number of tropical fruits in Northland.
Photo / Tania Whyte
Long periods of balmy weather means the likes of Hugh Rose can plant a number of tropical fruits in Northland.
Photo / Tania Whyte
It's all hands in the ground for tropical fruit growers in Northland relishing soaring temperatures and high humidity— an ideal combination to try on new crops that could reduce our reliance on overseas imports.
Mangoes, ginger, pineapples and bananas are doing well and growers say Niwa's climate outlook for thefirst quarter of this year predicting an 80 per cent chance of temperatures to be above average in Northland is "fantastic" news.
However, sweltering temperatures will create new biosecurity challenges by allowing a broader range of new exotic pests, weeds and diseases to take hold in Northland.
Dehydrated kiwi in particular could drown in water troughs and fishponds whereas the population of both sexes of the slider turtles in Northland waters could become harder to control.
Niwa has revealed 2021 was the country's hottest year in more than a century of records, with a mean land surface temperature of 13.56C— or just shy of 1C above the 1981-2010 average.
New Zealand's coastal sea surface temperatures ranged between 1.6C and 2.5˚C above average during December as La Nina strengthened in the equatorial Pacific and marine heatwave conditions intensified.
Due to marine heatwave conditions, Niwa is predicting periods of excessive humidity and hot temperatures are more likely.
Chairman of Tropical Fruit Growers of New Zealand, Hugh Rose, believes the potential for Northlanders to grow a variety of tropical fruits in ongoing high temperatures and humidity is huge.
"The potential is an absolute gift from God. Bring it on. We have the possibility of growing ginger and many other plants...cardamom and other such spices not typically grown up here can become the norm."
Only mountain variety coconuts the size of baseballs were presently grown in Northland rather than tropical ones that required more warmer weather, he said.
"Temperatures moving up a few degrees makes a huge difference and rather than relying on overseas imports, we could be growing it up here. A good thing about Northland's climate, generally speaking, is it's a lot better than in other parts of New Zealand.
"A lot of peat and acidic soil up here is absolute mana. The dairy industry has taken a huge interest in using banana leaves for cattle feed," Rose said.
Owen Schafli started growing pineapples in Parua Bay eight years ago and said the sweltering heat could not have been more ideal for their growth.
"This year, we've been quite blessed as we've had rain compared with the last three to four very dry summers. Rain from time to time is good and the temperature needs to be below 30C for ideal pineapple growth which we have up here," he said.
Commercial pineapple grower Owen Schafli and son Colin in their Parua Bay farm.
Photo / Tania Whyte
He grows the queen pineapple which is only grown in Australia, Philippines and South Africa and said the variety seemed to have adapted well to Northland's climate.
Schafli started with 400 plants and now has more than 30,000 spread over 1.2 hectares.
He will start selling his pineapples at the Whangārei Growers' Market between March and December.
Northland Regional Council deputy group manager biosecurity Kathryn Lister said it was important to consider the pest status of some species present in the region, and the impact they have, may change as a result of sustained increased temperatures.
In particular, she said innocuous "sleeper" weeds, pests and diseases may become problematic due to changing ecological interactions with host plants and natural enemies, or shifts in their own phenology.
Droughts in Northland impacted on kiwi productivity and delayed breeding the following season, she said.
"Delayed breeding means that kiwi chicks are born at the same time that stoat numbers peak and kiwi chicks will take longer to reach a stoat-safe weight – usually a kilo."
NRC biosecurity specialist for freshwater pests Raymond Tana said the viability of naturally-reproducing turtle population in Northland would be dependent on specific temperature conditions occurring during egg development.
He said if the ground temperatures ranged between 20C and 27C, the resulting offspring would be male, whereas if the mercury rose above 28 C, it would be both sexes.
Females would be born in temperatures above 31C.
"However, with increased temperatures through global climate change and 2021 already being touted as the hottest on record by Niwa, the limiting environmental temperature conditions once favouring males only, is likely to shift in favour of both sexes.
"If that occurs, the likelihood of slider turtles currently at liberty in Northland's waterways establishing self-recruiting populations will increase markedly signalling a turning point at which our efforts to control their spread will become a lot more difficult," Tana said.
There is also an increased fire risk, and the frequency of fire events can increase with hotter summers.
Fire favours pest plants such as wattle and Hakea.
Niwa is predicting rainfall totals are about equally likely to be near normal and an elevated chance for ex-tropical cyclone could increase the risk of heavy downpours.
Soil moisture levels and river flows are about equally likely to be near normal.
More Nothlanders will undertake outdoor activities as the warm weather is forecast to linger around longer.
Photo / Michael Cunningham
Leigh recorded the highest annual average temperature for 2021 with 17.6C, followed by Whangārei, Kaitaia and Auckland (Whangaparāoa) with 16.7C.
Kaikohe recorded the extreme daily maximum temperatures of 23.2C on October 26 and of 28.4C on Christmas Day since records began in 1973.
The town also featured in the maximum wind gust extremes of 89km/h, recorded in August.
Kerikeri recorded the highest mean air temperature of 16.1C since records there began in 1945, Kaitaia (16.7C) had the second highest.
Kaeo recorded the highest one-day rainfall since 1981 of 160mm, on October 23.
