January Citrus News ’26

Queensland fruit fly repsonse

By the time you read this article, the response to the recent detection of a Queensland fruit fly (Bactrocera tryoni) in Mt Roskill, Auckland will be entering its third week.

A single male Queensland fruit fly was found in a trap on 5 January during routine surveillance. Surveillance and trap checking within the immediate 200-metre zone around the find has been intensified, with additional traps placed within the zone. This is to quickly determine whether further flies are present and whether a population has established. Traps in this zone are checked daily, and to date no further flies have been detected.

Fruit growing within the zone is also being collected and inspected. Controls are in place to prevent the movement of host fruit and vegetables out of the controlled area, reducing the risk of any potential spread.

Queensland fruit fly is a highly invasive pest. In its native home Australia, it costs growers millions of dollars annually in damage and pest management. Adult flies lay eggs under the skin of host fruit, with larvae feeding inside and causing fruit to rot. There are more than 200 known host plants, including citrus, as well as stonefruit and tomatoes.

If Queensland fruit fly were to establish in New Zealand, the impacts on the horticulture sector would be significant. Trade access could be affected, production costs would increase, and yield losses may occur. Biosecurity New Zealand is working closely with GIA (Government-Industry Agreement for Readiness and Response) partners to minimise the risk to growers and exporters.

Citrus NZ is a signatory to the Fruit Fly Operational Agreement under GIA and has been involved in joint decision-making at response governance level.

 Want to be involved in a response?
The response contractor is occasionally seeking additional support for field operations. If you are interested, please contact .

More information on the Queensland fruit fly response in Mt Roskill, Auckland is available on the MPI website.

Drinking Water Compliance

Growers who supply drinking water to staff or other people will need to check whether they need to be in compliance with the Water Services Act 2021. This could apply to you if you provide drinking water in workers’ accommodation, in smoko rooms or shared with neighbours.

The Water Services Authority, Taumata Arowai, is the responsible government agency. To find out if you are a supplier, check on their website.

If you meet the definition of a drinking water supplier, you will need to register your supply with the Authority by November 2028. Read more here.

2025 Clark Fletcher Memorial Citrus Scholarship Recipient

We are delighted to award the 2025 Clark Fletcher Memorial Citrus Scholarship to Millie Galloway.

Growing up on her family’s mixed citrus orchard in Gisborne, Millie has gained practical experience across all aspects of orchard operations, from planting and pruning to redevelopment with new varieties. Combined with her strong academic performance and leadership, she represents the capability and drive we need in the next generation of horticulturists.

This year, Millie will begin a Bachelor of Land and Property Management at Lincoln University, where she will study soil science, economics, land systems and primary industry management. She is passionate about helping citrus growers lift profitability, diversify into value-added products, and strengthen the long-term sustainability of the sector.

Supporting Millie aligns strongly with the industry’s commitment to developing the next generation of skilled, innovative horticulturists who will support New Zealand’s citrus industry.

2026 MRL and PHI charts available online

The 2026 MRL and PHI chartsfor mandarins, oranges and lemons are now available to download from the Members’ Portal. Simply log-in and navigate to the Crop Protection module.

Growers who would like a printed copy can register their interest here, and we will arrange for copies to be posted in early February once printing is complete.

If you have any questions, please email 

Satsuma Thinning

This time of year is particularly critical for early Satsuma growers when it comes to fruit thinning. Early varieties of Satsumas such as Miyagawa, Miho and Okitsu are naturally biennial, and in an “on” year they tend to overcrop heavily. Without intervention, this results in smaller, misshapen fruit that is more prone to pest damage such as Greenhouse Thrip and clipper injury. The best returns for Satsumas come from large, high-quality fruit, which is ultimately what growers should be aiming for.

Chemical thinning (NAA), usually applied in November (depending on conditions), can be a useful tool to reduce the cost of hand thinning. However, it isn’t always possible to apply this at the right time, so hand thinning often remains necessary. Even where chemical thinning has been used, it is common for some trees or heavy bunches to still require manual thinning.

A common issue is that growers simply don’t thin enough! Removing fruit is always difficult, but the focus needs to stay on the end result – fewer, larger, higher-value fruit that are cheaper to harvest. When thinning, visualise how large the fruit will be at harvest. A good guide is the four-finger span of your hand on fruit is a good indication of the space required. Also check the balance between fruit and leaves. Leaves drive fruit growth, so if the ratio of fruit:leaf is out, fruit size will suffer.

Later Satsuma varieties such as Silver Hill, Kawano and Aoshima can also benefit from thinning bunches for cosmetic and quality reasons. However, because these varieties remain on the tree longer, they tend to size more naturally – particularly Aoshima.

Hand thinning of fruit can leaves open wound on the peduncles (fruit stems). As soon as practicable after thinning, apply a fungicide to help reduce disease risk and limit spread.