Keeping Biosecurity Boring

By Rachel Masters, Biosecurity Manager, New Zealand Apples & Pears

The best biosecurity outcome is a boring one.

If there is one thing I would love fruit growers across Hawke’s Bay to remember during Biosecurity Awareness Month, it’s that.

Boring means no emergency response meetings. No movement controls. No market disruptions. No unwanted pests or diseases threatening our orchards, businesses or livelihoods. It means growers can focus on producing great fruit and getting on with the season.

Last summer was anything but boring. Over the past year New Zealand has responded to multiple fruit fly detections, the yellow-legged hornet incursion, and a range of other potential threats. We are also watching avian influenza developments closely, as it serves as a reminder that biosecurity risks are constantly evolving and arrive on our shores in a number of different ways.

The positive side of these incursions is that they show New Zealand’s biosecurity system work. Someone noticed something unusual. It was reported. Surveillance systems did their job. Response teams mobilised quickly.

Early detection and rapid action remain our greatest advantages when protecting New Zealand from unwanted pests and diseases

For the apple and pear industry, one of the most important tools supporting that response capability is the Government Industry Agreement (GIA). Through GIA, industry and government share responsibility for preparing for and responding to significant biosecurity threats.

It gives industries like ours a seat at the table during decision-making and ensures practical grower perspectives are considered when response actions are developed. It also helps strengthen readiness long before a pest or disease arrives

But no agreement, plan or organisation can do this alone.

Biosecurity starts with people. It starts with growers inspecting orchards, staff questioning something that does not look right, businesses integrating biosecurity into everyday activities, and individuals reporting unusual pests or symptoms. Every person in the supply chain has a role to play.

This Biosecurity Awareness Month, I encourage everyone to take a fresh look at their biosecurity practices, talk with their teams and make preparedness part of everyday business.

Because when we work together, stay vigilant and share responsibility, we give ourselves the best possible chance of keeping biosecurity exactly what it should be: boring.

Hi All

Just a couple of updates on RMA matters:

• There has been some chatter recently about the progress of the TANK Plan Change, and the possibility of the Regional Council withdrawing it. However, at this stage the Regional Council has decided to continue with the current Environment Court appeal process, which means that TANK remains relevant. The Regional Council is going to revisit this after the General Election in November, but in the meantime, there is no change to the situation that we have been in for the last few years.
• The Natural Environment Bill and the Planning Bill (which will replace the Resource Management Act) are being considered in parliament this week. Possible amendments to the bills are being discussed, and changes will potentially be made. Once this process is complete, the Bills will go through a third and final reading, before they receive royal assent. This means that within the next month we should know the final wording of these bills, which will provide a bit more clarity about what resource management will look like moving forward.
• As we come into a new irrigation season, please make sure that water meters and/or telemetry units are working well and accurately recording all water used. Having accurate water use records is going to be important no matter what the new resource management system looks like, so make sure your system is working well, and that you periodically check it, to make sure it continues to operate correctly over the coming season

 If anyone has any questions or queries in the resource management space, please do not hesitate to contact Charlotte Drury on 027 3225595, or Charlotte.Drury@hortnz.co.nz

On the back of one of the coldest weeks Hawke’s Bay has seen in a long while – -6 °c reported in parts on Friday 07/08 and snow to low levels on Tuesday 04/08 – we’re also seeing hints of spring.  Bud burst has been reported in the first of the grape blocks, and some sheltered areas of stone fruit are well advanced – spring is sneaking in the door.  Given the critical nature of the spring growing period, and the potential for multi season impacts, it’s integral to ensure everything you can control is well organised:

• Sprayer calibrations – Chemical thinning will come around fast and inadequate thinning can lead to biennial bearing. Similarly, weather conditions into spring are likely to bring strong El Nino winds so ensuring you achieve optimal coverage will mitigate risk.
• Water – El Nino is coming on the back of a dry winter for parts of the Heretaunga. While we don’t know exactly how this will play out, water stress can cause premature termination of growth and trigger low production. Make sure your irrigation systems are checked, serviced, and ready to go as recent frost events have created a range of damage and controlling water stress is a key pillar of success.
• Fuel – Uncertainty continues and fuel prices continue to be volatile. Before the season kicks off in earnest, it is timely to check on farm security to limit the opportunity for thieves. Also timely to also ensure all plant and machinery is operating as efficiently as possible – well serviced, reliable machines will limit the total seasonal fuel bill.
• Frost & Wind – We are forecast to head into a super El Nino event, however forst risk is expected to remain within the normal range and equinox winds will not be far off. A good time to ensure that all management methods available can be readily implemented – For frost, short grass swards, under tree irrigation, bare moist earth within weed strips, and urea foliar sprays can make 0.5 – 1.0°C difference. For wind, shelter and tree training are the pillars – make sure adequate tree support is in play;
• Fertiliser – If any soil nutrients need adjusting into their optimal ranges, this needs to be completed prior to budburst. If not already done, urgency will be needed!
• Development – If you’re undertaking development, make sure the fundamentals of establishment are right. Right depth, right conditions, and right protocols. Ensure trees are rehydrated prior to planting, that they are placed at the right depth, and soil is properly prepared for good contact when firming them into the ground.
• Orchard Hygiene – Winter conditions across the plains have been mixed, with notably dry areas. If you in a dry and cold area where leaf decay has not fully occurred, be wary of blackspot infection. Sweeping and mulching prior to green tip can help reduce infection pressure.
• Gray Matter – There’s no substitute to getting your own head in order leading into the system. Checklists / brainstorms / work programmes – use whatever works for you. Think laterally, be analytical, be realistic on your resources and you’ll be set!

If you feel something strategic is missing or are looking to invest in another pair of boots to give a second opinion, give AgFirst a call.

Carl O’Brien

Heretaunga Sustainable Water is holding a meeting on Thursday 30^th July at the Havelock North Function Centre. It will kick off at 4pm and (as well as incorporating the groups AGM) will provide updates on the work the group has been involved in over the last year. Members and anyone who is interested in becoming a member is encouraged to attend to find out what the group has been doing to try and improve water security on the Heretaunga Plains

Optimising Chemical Thinning: Removing Some of the Magic Arts

Every spring I end up having the same conversation with growers: “Why did thinning work so well in one block and not another?” Or, “The weather looked right, the chemistry was the same—what went wrong?”

The reality is that chemical thinning is often treated as a bit of a magic art. Yet when we step back and analyse the blocks that consistently achieve good crop loads, fruit size and profitability, a pattern emerges. The best outcomes are rarely the result of luck. They are the product of planning, measurement and execution. The more information we collect and use, the less guesswork (magic art) is involved.

Before discussing thinning chemistry, growers need to define what success looks like for each block. That target will vary depending on variety, fruit size requirements, canopy capacity, site limitations and hand-thinning budgets. A crop load that is profitable in one block may be completely wrong for another. The objective is to identify the crop load that delivers maximum return at the desired fruit size and quality.

Once a target is established, everything else should work backwards from it, pruning, flowering assessments, thinning strategy and eventually hand thinning.

One of the biggest opportunities I see is making better use of information growers already have. Review previous seasons and ask:

• Did crop loads finish where they were intended?
• Did fruit size and quality meet expectations?
• What flowering and pollination conditions occurred?
• What chemistry was used and under what conditions?
• How much hand thinning was required afterwards?

Historical data helps identify what worked, what did not, and where changes need to be made. Too often thinning programmes are repeated year after year without considering whether the previous result actually matched the target.

Chemical thinning outcomes are largely influenced by four interacting factors:

1. The Target –Tree age, vigour, canopy balance, crop pressure and pollination strength all influence how aggressively a block can be thinned.
2. The Chemistry – Product choice, rates, surfactants, water volumes and timing all matter. Understanding how each product works and recognising the conditions it needs to perform is critical.
3. The Weather – Temperature, humidity, rainfall, frost risk, sunshine and carbohydrate status can dramatically alter outcomes. Weather frequently determines whether an application succeeds or disappoints.
4. The Application – Even the best thinning plan can be compromised by poor application. Sprayer calibration, water quality, nozzle selection, coverage consistency and target zones all influence performance.

When thinning results are poor, the answer often lies somewhere within these four areas.

One of the key messages from our work is not to overcomplicate the process. If a programme is consistently delivering good results, do not change it simply for the sake of change. Instead, focus on understanding why it works. Standardise rates, water volumes, surfactants and application methods wherever possible.

Perhaps most importantly, target optimum weather over optimum growth stage. A perfectly timed application applied in poor conditions is often less effective than a slightly later application applied under ideal conditions.

To me, the best chemical thinning you can do is the have boots on the ground. No model or forecast replaces regular orchard observation. The most successful growers are constantly checking blocks, monitoring progress and adjusting plans when conditions change. Chemical thinning should not be a “set and forget” exercise. The orchard is providing feedback every day, it is up to us to listen to it.

Take-Home Message

Crop load remains one of the biggest drivers of orchard profitability. The ability to manipulate crop load early and accurately influences fruit size, quality, labour requirements and ultimately financial returns.

The more disciplined we become around planning, measurement and execution, the less chemical thinning feels like a magic art, and the more it becomes a repeatable management process that consistently delivers profitable outcomes.

Jack Wilson

RMA update:

HortNZ is aware that a number of growers who lodged replacement water take applications last year (or early this year) for consents that expired on 31 May 2026 have recently received emails from HBRC asking them how they want to proceed with their consent applications. Many of these growers are in the Pakowhai area, or take water from the Tutaekuri-Waimate Stream.

We understand there are a number of slightly different emails from the regional council, depending on what has happened in each consent process to date, which is really confusing. We don’t want to add to the confusion by trying to explain things again in a slightly different way, but instead ask people to get in touch with Charlotte Drury on if they want to discuss what might be best in their particular situation

Also please be aware that if you do decide you want to withdraw your application, HBRC is requiring people to fill in a form to complete that process. Here is a link to it: Application-Form-Surrender-Withdrawal-V01-0326.pdf

You should be able to fill it in online, and then you can email your completed form to the consent advisor at consentadvisor@hbrc.govt.nz

Any questions, get in touch with Charlotte Drury (027 3225595 or Charlotte.Drury@hortnz.co.nz)

A bud to fruit ratio is the number of fruit buds in a tree relative to the target number of harvested fruit. Fruit bud numbers directly correlate to the number of floral sites expected in spring and can be used to manipulate vigour status and fruit size outcomes.  If not pruning to a target bud number, an understanding of the post prune bud count can guide chemical thinning decisions (how hard they need to go, and the level of floral stress the tree may already be under at flowering).

Bud density and quality are driven by light, varietal tendencies and branch texture.  It’s about having the right wood, and good light capture through the tree. Getting to this point without compromising yields may be a 3 to 5 year journey.

As a tree matures and settles, bud numbers tend to increase, particularly in spur varieties. In the spring, flowers acts as a carbohydrate sink when the plant is not photosynthesising, drawing solely on reserves. With a high bud to fruit ratio, the floral stress induces an ethylene spike, resulting in the plant prioritising ‘survival’ over fruit set and influences spring carbohydrate efficiencies.  This can help with vigour reduction strategies.

Running a low bud to fruit ratio is a well-utilised strategy in young canopies prioritising growth, or when trying to get a jump on fruit size in spring, particularly in a settled canopy.

There is no hard and fast rule, and not all fruit buds are equal.

Best practice winter bud monitoring includes:

Fruit bud counts: Count all fruit buds regardless of size and shape, including spurs and terminal buds on darts and bourse shoots. For tip-bearing varieties, don’t be tempted to count one-year buds. These are treated as ‘bonus flower’ due to their lower reliability and typically do not produce the highest quality fruit within the tree.

Most growers count buds as a tree average to understand the overall floral load, however splitting the tree into zones allows growers to target buds in specific parts of the tree. Where are the quality buds located and where can we target detail pruning? In a 2D system this could be the target number of buds per wire; in a spindle tree, this could be splitting the tree into bottom, middle and tops. When quantified, this helps refine pruning instructions with confidence that the target cropload will still be achieved.

The budload in the attached photo shows a settled tree with a very high bud density in the tops.

Fruit bud floral capacity assessments: Fruit buds are sampled pre-pruning and assessed under the microscope to determine their floral potential. This is a best-practice winter pruning

metric, helpful on blocks where floral capacity is unknown or on biennial varieties, particularly in an off year. This allows growers to dial their bud to fruit ratio up or down.

Used well, bud to fruit ratios help growers align pruning, thinning and crop load decisions early, giving blocks the best chance of achieving the desired vigour status, target fruit numbers, fruit size and quality.

Meg Becker

NZAPI Update

There’s plenty happening across the horticulture sector as we head into winter.

Congratulations to Central Otago Young Grower of the Year winner Luke St John, who will now progress to the national final later this year. Closer to home, we’re looking forward to welcoming competitors, sponsors and supporters to the Hawke’s Bay Young Fruit Grower of the Year competition on 18–19 June.

NZAPI has also announced details for its Annual Conference and AGM, taking place in Queenstown on 22–23 July. The conference is a fantastic opportunity to hear industry updates, connect with growers and sector leaders, and discuss the opportunities and challenges facing New Zealand horticulture.

Members can also save the date for the Orchard Research Review on 2 July, which will showcase the latest orchard-based research and provide an opportunity to contribute to future industry priorities.

For more information on these events, conference registrations, industry updates and member resources, visit the NZAPI Members Portal and website.

https://www.applesandpears.nz/

European Canker Best Management – Protecting Leaf Scars.

The recent rain events have created ideal conditions for EC. Soon tens of thousands of leaf scars will be created during leaf fall. It’s important you have a program to protect these wounds from infection. Do not underestimate the impact this disease can have on the economic viability of your orchard. Do not be complacent. It’s an aggressive disease which requires and equally aggressive response.

Best practice includes:

1. Canker walk your blocks NOW. Cut, remove and burn. Lowering the inoculum level in the orchard is the No.1 management tool. You can’t rely solely on spraying your way out of this disease.

2. Commence weekly Captan &/or Copper sprays between 10% and 90% leaf fall. At least 3-4 applications over the leaf fall period. Additional applications will be needed immediately following rainfall events.

3. The Copper & Captan a.i. rates are important for efficacy. Copper a.i. rate is 1.0 kg/ha, Captan a.i. rate is 2.0 kg/ha. Note: do not exceed 5.0 kg Cu/ha/year.

4. Check pH of spray solution. Captan needs buffering to <6.5 to ensure it does not hydrolyse (breakdown).

5. Adjust water rates to achieve complete coverage. Check/test sprayer set-up to ensure even spray deposition. This is crucial for maximum protection.

6. Consider assisted leaf drop sprays, e.g. EDTA Copper, in known high-risk blocks. You must wait until natural leaf has started (~5% leaf fall) before application. Shortening the period that scars from fallen leaves are susceptible to infection reduces the risk of European canker infection. Captan/Copper sprays to cover the wounds is still essential.

7. Do not apply foliar Nitrogen once leaf fall has started. This increases EC infection risk. If Urea is required for black spot clean-up, wait until all leaves have dropped and apply as a 5% solution to the ground.

Note: Sprays are supplemental to an aggressive cutting, removal and burning of inoculum from the orchard.

Dean Rainham, AgFirst Consultants

HAG (Horticultural Advisory Group)

The Heretaunga Sustainable Water (HSW) steering committee continues to meet on a monthly basis to review project updates and set priorities.  HSW exists as a forum to advocate and coordinate work that supports long-term (100-year) water security for the Heretaunga plains.

In April the HSW steering committee met with representatives of the Tukituki Water Security project.  This project has successfully secured funding to complete feasibility analysis, geo technical testing and design work.  Mike Scott, former CEO of Waimea Water has been appointed as CEO for Tukituki Water Security project and Mike Petersen is  Chair of the project governance group. The site of this proposed dam is the same as the former Ruataniwha dam proposal but due to changing regulation and other factors, significant changes to the original design of the dam have been undertaken.

The HSW steering committee are also receiving regular updates from the Heretaunga Water Storage project which has selected a site at Whanawhana as a preferred water storage scheme.  This project has also been successful in securing funding to advance feasibility analysis including geotechnical and engineering design work and has a governance group including representatives of local government, mana whenua and industry.

Both water storage projects are progressing well at this time and are confident that they can provide viable solutions that will greatly enhance water security on the plains.  The HSW steering committee will continue to engage with both project groups as further information becomes available on economic, environmental, technical and cultural factors over coming months.   Other project work underway includes analysis of current water abstraction along with 3D models of the aquifer to determine locations where aquifer recharge could be possible.  Members of HSW can expect a newsletter update soon including details of an AGM meeting.

Richard Pentreath
Chair of HAG