Whitehall kiwifruit growers come out the other side of Psa disease
It's been a slow road to recovery for Mark and Robyn Gardiner since Psa ripped through their kiwifruit business.
Called Seudomonas syringae pv. actinidiae, the deadly viral disease was first discovered at their 200 hectare Whitehall Fruitpackers operation in 2010.
Left unchecked, Psa destroys green and gold vines and spawns leaf spotting, cankers and shoot dieback.
At the worst point of the outbreak, Mark cut out 40ha of his 16 Gold kiwifruit crop as well as partial cuttings of green fruit. At the same time, the more resistant G3 variety was grafted to the vines.
"It's a lingering cancer that can break out. It you don't deal with it, it can destroy plants and destroy orchards."
Only now do they feel like they have come out the other side, Mark says.
The view from his office window at Whitehall's packhouse and storage facility of the lush, green vines full of this year's fruit is deceptive.
Removing the disease remains an ongoing maintenance issue and his staff are still finding it on the plants.
"It's not what it seems and the carrying capacity of those vines is very poor," he says.
Walking through one of the fruit blocks, his expert eye spots a small branch infected with the disease.
"You see how it's died?" he says.
Next to it is a healthy cane (branch) full of leaves and fruit that is almost ready for harvest.
"It's quite amazing how it can do that."
Son Ben is Whitehall's operations manager. He says they do everything possible now to ensure the vines are in the best possible health so they can resist Psa in spring if it starts to show.
They use a lot of copper-based sprays and try to keep plants in the best possible health to prevent the disease. It has become standard procedure for staff during winter pruning to sterilise their equipment in between vines to prevent cross-contamination.
"As soon as you see any kind of infected material, you cut it out - especially in the gold because it is slightly more susceptible," Ben says.
The Gardiners are one of Waikato's largest growers, planting their first vines in 1975. Their operation, including off-site blocks, totals 200 canopy hectares while the home block south of Cambridge and next to Lake Karapiro is 42ha.
The family business includes wife Robyn and three of their four children are involved in running it.
They are bio-grow certified and are the largest organic green kiwifruit grower in New Zealand, growing the G14 green variety, and G3 gold.
Growing organic fruit was challenging because it limited what inputs could be used, but generated a $2 per tray market premium compared with conventional green fruit.
"We chose kiwifruit because we felt there was a real growing demand for it and the market was there," Mark says.
Growing kiwifruit in Waikato has its own challenges compared with the Bay of Plenty. While the winter chill allows for better bud break, its wetter and colder climate helps Psa's survival on the vines.
It's harvest time at Whitehall and Mark expects about 15,000 trays of gold to be packed with replacement vines planted in the wake of Psa only cropping for the first time this year.
This is the busiest time of the year with workers picking the fruit and transporting it to their packhouse where it is cleaned, graded, packed in cardboard boxes and stored in their refrigerated warehouse.
About 200 people are employed during the harvest peak and 150 for the rest of the year, with many of the harvest staff shifting to other jobs in the business in the off season.
There is a strict process Zespri uses that governs when the fruit is ready for harvest. This is based around the fruit's brix (sweetness) and drymatter content. Fruit is also inspected for its softness, size, fruit and seed colouring and skin blemishes.
Waikato kiwifruit trees grows best in a well sheltered northerly facing spot that receives plenty of sunshine, is frost free and receives moderate rainfall with good free-draining soils, Mark says.
"If you try to grow it in the extremes where it is very cold or dry you run into problems. It's got to have that balance, it's like a semi-subtropical vine."
He says they use a lot of compost instead of chemical fertilisers to stimulate the "zoo" of the soil.
"We don't treat the soil as a chemical carrier. It's a living thing because it's full of life if you treat it right."
As a low nitrogen leacher, it remained to be seen what effect the Healthy Rivers plan change would have on the family's business. If the plan change went ahead unchanged, they would be submitting a low nitrogen reference point to the council which could limit any future development.
"We feel like we are the good guys with what we are doing here and why should we be penalised."
In the orchard the canes are heavy with fruit and the slightest touch sees them fall from their stems. They are harvested hard and soften by the time they reach consumers, he says.
Each cane only bears fruit for one year and hanging above the canopy are fresh canes called teepees because of their distinctive shape.
These cane will grow next year's fruit and once the harvest is over, the empty canes will be cut off and the hanging branches will drop to form a new canopy.
Whitehall is one of a handful of kiwifruit operations in New Zealand equipped with its own packhouse and refrigerated storage facility, that processes 1.6 million trays a season and packs 3000-4000 trays an hour.
Zespri's strict traceability rules mean the fruit is processed from one block at a time so any issues can be traced back to the vine. Once at the packhouse, the full bins are emptied onto a conveyer belt that sends kiwifruit into the packhouse. The empty bins are then sanitised before returning to the truck.
The fruit is cleaned and travels through into the shed where each one is examined and evaluated by graders. Any fruit that does not reach the required specifications is rejected while the rest is graded into class one, two or three.
"The whole system is built around quality," Mark says.
Quality control people also sample fruit from the graders to ensure they are properly sorting the fruit.
Any rejects are sold to dairy farmers for stock food.
The fruit then travels down the line according to its class. The top class one fruit is unblemished without marks and has a specified shape. It is then electronically weighed and a sticker label is designated based on that weight.
Mark says more than 90 per cent of their gold kiwifruit is graded as class one.
"It's pretty much the perfect fruit," he says.
A computer sends the fruit down a specific conveyer belt, based on its weight reading, to one of 24 lanes to the packer who places the fruit into the box for storage and then shipping. Each box also has its own information label.
The other two grades follow a similar selection criteria to ensure the fruit meets the appropriate standard although there are bigger allowances.
Next to their packing house is a refrigerated storage facility, which can hold up to two million trays of kiwifruit stacked in large cubed pallets, sorted according to variety, grade and destination for the domestic or export market.
The large stacks are boxed and labelled with codes identifying where and when it was picked, what type of fruit it is and where it is headed. The labels are also pasted onto the individual boxes.
Locally, their green fruit is sold in organic markets and supermarket companies across the country.
Zespri also stagger the release of the fruit into the market with some trays staying on site in storage through to November.
The kiwifruit co-operative provides incentives to its growers to supply fruit at the shoulders of the season to ensure market supply. The latest Whitehall has sent fruit is December 23.
Mark believes the industry now has a bright future with average returns for gold kiwifruit at about $98,000 a hectare before packhouse costs are factored in, while the average costs to produce a hectare of the fruit is about $30,000/ha.
Gold kiwifruit has become extremely fashionable to eat and is in high demand after changing from a luxury item to a dietary staple, Mark says.
He is also a firm backer of Zespri's single desk selling system because of their marketing credibility.
"It's got all those things that make it a good industry."