Mandarin Harvest in Northland

According to industry statistics there are roughly 240 mandarin growers in New Zealand with a total planted area of 361 ha. Crop volume sits around 9-10,000 tonnes per year, which is harvested over a three to four month period. Gisborne and Northland are the most popular growing areas. Northland produces a slightly higher volume.

Going back to the early days of the industry, citrus orchards were established on small blocks in Kerikeri, from State Highway 10 to Inlet Road, where the Davies’ family orchard is located today. The orchard produces roughly 4 – 500 tons.

Brad Davies’ father was heavily involved in the citrus industry and was one of the mandarin growers enthusiastic about putting New Zealand product into the Japanese market.

Kerikeri has an ideal microclimate for citrus. Brad says the area delivers fruit that is consistently good. The area is sub-tropical which provides some challenges from a humidity perspective, more so than Gisborne which is the other mandarin growing area.

In the past few seasons, supply has exceeded demand on the domestic market, meaning a slump in prices for grower.

Brad is mandarin group chairman for NZ Citrus Growers. He says this season the industry is looking in pretty good shape and that balance between supply and demand is a lot better than it used to be – 5 to 6 years ago.

He says the sector, like many others, is facing an ageing population of growers which is a concern long term. Brad says there’s room to expand production but that’s mostly in the earlier and later varieties to give more of a wider spread to the markets.

The Davies’ orchard is a mix of 16 canopy ha of satsuma mandarins, typically Japanese varieties. The satsuma is an easy peeling, seedless variety named after the former Satsuma province in Japan from where this variety was originally exported to the West. One of the other distinguishing characteristics of the fruit is the thin leathery skin.

The harvest is fast moving. Crop starts coming off the trees in the last week of April and by the second week of May harvest is almost 50% through.

There’s a difference between Northland and Gisborne in terms of market mix. Typically Northland growers chase the early season market with fruit into Japan with product of a very high spec. Export markets can account for roughly 30 to 40 % of the volume out of Northland – the rest is domestic market. From a total industry volume – only roughly 15% goes off shore.

Brad says mandarins face the same or similar challenges to most of the other sectors. He says biosecurity risk is a big concern. He says the industry is doing a reasonably good job of continuing to grow the market and working hard to continue to improve the taste attributes of the product.

Pruning is a big part of mandarin orchard management. Growers have to maintain a very open structure on the tree to stay on top of pest and disease. In January when the fruit is very small, orchard staff manually thin the crop and typically take the volume of fruit down by as much as 50% so the trees don’t overload.

One of the key elements in the fruit is sweetness. Brad says this is a challenge. Trees are planted on a mound so water drains away from the roots. Some growers use reflective sheets on the ground to bounce light up into the tree to promote maturity and colour. During the early period of the year they will stress the trees by restricting water. This has the effect of promoting the sugars in the fruit. He says the market looks for internal quality and eating experience as much as the cosmetic appearance of the fruit.

Because of climate, fungal pressures can be quite high, so growers need to apply targeted fungicides. Pest pressures are monitored and growers use very target specific products to control pests. Consumers are these days asking for minimal residues in fruit and growers have to be rigorous in only applying chemical when it is required.

In the lead up to harvest, growers are looking for the right ratio of brix and acid in the fruit. Mandarins are monitored from early in the year to see how they are tracking in terms of maturity. There are parameters for both domestic and export fruit. Later in the season when the fruit has started to get to the right colour, fruit samples are delivered to the packhouse where they are tested to make sure the growers are meeting those standards.

The Japanese market has a preference for smaller fruit – typically 50-60mm is ideal. That fruit needs to be blemish free and needs to have an internal brix of over 10.5 to 11 and an acid below 1.2.

Harvest crews are a mixture of local permanent staff and RSE (Recognised Seasonal Employer) workers. Brad says he enjoys the continuity that the RSE workers provide which also means he’s not re-training a new group of pickers each harvest season.