Dear Trevelyan’s kiwifruit grower,
This weeks Kiwifruit TechTip looks at industry fruit development trends, Zespri 2021 license application, high temperature fruit at harvest, unlocking spray diary, Trevelyan’s 2021 Winter Spray Guides, pre-harvest stain removers and drying fruit quickly, thinking about harvest and upcoming events.
Industry fruit development trends
This week Abdul Jabbar (Zespri’s Fruit Optimisation Leader) shared some industry insights from Smart Monitoring data at Week 11. In summary Abdul states:
SM and Monitoring – Gold3 Summary at Week 11
- Mean fresh weight is 133.3 g, this seems ̴11 g higher than 2020 and ̴5.9 g higher than 2019 at the same given week.
- Mean DM is 17.3 %, that’s 0.3-0.5% lower than 2019 & 2020.
- Mean SSC is 5.8 °Brix and lower fractile is 4.63 °Brix. Both parameters are ̴0.7 °Brix lower than 2020 but slightly (0.11-0.16 °Brix) higher than 2019 at given week 11 comparison.
- Average °hue is at 107.6; Green fractile of 112.44 °hue & colour threshold of 110.84 °hue. We learnt that week 9 colour data had some inconsistency therefore removed from the trend’s graphs.
- Average firmness is 7.05 kgf and soft fractile is at 5.74 kgf. Firmness seems to have dropped quite a bit (on an av. 0.9 kgf less than 2020). Firmness trend for 2021 needs to be observed in coming weeks as softening curve will define.
SM and Monitoring – HW Summary at Week 11
- Mean fresh weight is 96.9g
- Mean DM is at 16.12 %
- Mean SSC is at 4.72 °Brix and lower fractile is 4.21 °Brix
- Average firmness is 9.53 kgf and soft fractile is at 8.06 kgf
Fruit firmness (or lack of is a concern this harvest) as illustrated by the graphs below:
Figure 3. GA Mean Firmness (KgF) vs ISO Week – the 2021 (black line) is below all other years graphed
Figure 4. GA Soft Fractile (KgF) vs ISO Week – the 2021 (black line) is below all other years graphed
Figure 5. HW Mean Firmness (KgF) vs ISO Week – the 2021 (black line) is below all other years graphed
Figure 6. HW Soft Fractile (KgF) vs ISO Week – the 2021 (black line) is below all other years graphed
For more detail please see the attached document
The 2021 Zespri licence application process is now open
The Zespri Licence Application window is from Friday, 26 March 2021 until 5.00pm, Wednesday, 7 April 2021. All bidders should undertake full due diligence before bidding for any Zespri Variety Licence. All bid application forms, NVIG’s, guides and supplemental information can be found on Canopy here.
Those considering Red19 license should be aware of the Addendum for the 2021 Red19 NVIG that highlights additional information learnt from the 2021 Red19 harvest that all bidders should read prior to submitting a bid here.
|26 March 2021||Supplemental Information relating to Red19 Licence Release published.|
|26 March 2021||Application process opens|
|7 April 2021||Closing date for Bids (5.00pm)|
|21 April 2021||Preliminary Revenue Range announced|
|28 April 2021||Pre-validation and collation of all Bids completed by Cooney Lees Morgan|
|29 April 2021||Evaluation Panel makes decisions regarding allocation of licences and successful bidders notified by email as soon as possible thereafter (estimated 3 May onwards)|
|*6 May 2021||Deposit monies due for payment by EFT for successful Bidders (at least three day’s advance notice will be given)|
|25 May 2021 onwards||Licence packs distributed to successful Bidders|
|20 July 2021||Deadline for paying settlement monies and meeting all other settlement requirements|
*Dependent on the date of notification to bidders.
High temperature fruit at harvest
One of the factors that determines a successful storage outcome for your fruit is managing the cool chain. Science tells us that once harvested, kiwifruit continues to respire, absorbing oxygen while releasing carbon dioxide and ethylene which results in the ripening of the fruit. The rate of which the fruit respires is directly influenced by temperature (as well as fruit maturity and gases in the environment). Our coolstore team do an excellent job of managing these factors when your fruit is on site, but are already on the back foot if the internal temperature of the fruit is high when it arrives. At this time of year our Operations Team constantly monitoring the internal colour of Gold3 fruit and the coolstore environment, lowering temperatures and/or moving product lines to ensure colour protocols are optimised to meet Zespri’s orders. Lines of “hot” fruit make this task more difficult as they affect the performance of other fruit in the coolstore (due to heat and increased respiration rates), or to the line itself as it may not de-green as expected.
Each truckload of fruit arriving at Trevelyan’s is monitored with the temperature of the fruit in the bins recorded. Unsurprisingly we’ve had some high fruit temperatures recorded with the hot weather we’ve been having recently, but what is surprising however is the “degrees above ambient air temperature” that has been recorded on some milder days. For instance, we’ve seen trucks arriving with fruit temperatures of 33°C when the ambient air temperature (in the shade) is only 18°C – that’s a difference of 15°C! This suggests that the bins have been left sitting for some time in the direct sun before being loaded onto the truck, rather than sitting in the shade.
Where possible, try to arrange the layout of your loadpad to allow for full bins to be stacked in the shade through the day, particularly in the afternoon. This way the potential for the fruit to heat up in the bins prior to packing is minimised and helps ensure the best possible outcome for your fruit.
Unlocked your spray diary? Don’t forget to resubmit for “main audit” once you’ve made your changes!
Once you have submitted your spray diary for a main audit, it is locked and no further changes can be made. If changes are required, you can contact Zespri and ask them to “void” the main audit – this will allow you to make changes to your spray diary (i.e. add spray lines, edit blocks etc).
Once you’ve finished making changes however, you’ll have to resubmit your blocks for “main audit” again, otherwise you won’t be cleared for harvest!
Trevelyan’s 2021 Winter Spray Guides – Conventional and Organic
The Trevelyan’s 2021 Winter Spray Guides for conventional and organic growers are available here on the Trevelyan’s website. Please note that the sprays and timings are suggestions only and the unique circumstances on your orchard(s) may require a different approach to spray management. Not all sprays listed in the Zespri Crop Protection Standard (CPS) have been included, so you may like to consider further options by reviewing this document (found here on the Zespri Canopy website).
Organic/organic conversion growers are reminded that all inputs must also be BioGro™ certified (as well as allowed by Zespri) – please check with BioGro™ that organic status of every input before application
If you have any questions regarding the 2021 Winter Spray Guide, please do not hesitate contacting me or your Grower Representative.
Pre-harvest stain removers
Clean-up sprays are often not required during the KiwiStart period as leaf quality is good and the fruit is not stained from tannins produced as leaves deteriorate later in the season. However, if you choose to use a cleanup spray during KiwiStart:
- Conventional growers – calcium phosphate/phosphoric acid cleaners such as CP Clean™ are good options for early harvested fruit.
- Cleaning is completed once the product is dry and apply at of 5L/1000L – applied at 1500L water/ha in both directions (total 3000L water/ha minimum).
- Organic/conventional growers – citric acid is an effective option (and the only option for organic growers), but there are occasional reports of some stains “re-staining” in coolstore.
- Apply at 5kg/1000L – applied at 1500L water/ha in both directions (total 3000L water/ha minimum)
Struggling to harvest wet fruit? Du-Wett° and Du-Wett° Stainless may speed up conventional fruit drying times
Laboratory trial data I reviewed in 2019 suggests that the Du-Wett° and Du-Wett° Stainless can speed up drying times on wet fruit. Due to the nature of organosilicone superspreaders, water deposited on the surface of the leaf is spread more evenly and as a thinner film compared to what is normally deposited without the use of a superspreader. This can be extremely useful if your fruit is wet and you’ve got pickers on standby!
Data suggests that in the laboratory, Du-Wett° applied at 1L/ha in 500 litres water nearly halved the time for wet fruit to dry. Observations of growers in the field support this lab data.
If a quicker drying time is required, consider using:
- Du-Wett° when no stain removal is required
- Du-Wett° Stainless when a stain removal product is being applied
Don’t forget however, if you plan on putting a sprayer through your orchard immediately prior to harvest, first lift your crop to at least 1.5m above the ground as to minimise contact with the fruit.
Thinking about harvest…
Just a few things to think about as harvest is drawing near:
- Lift low hanging fruit – anything lower than 1.5m is likely to make contact with sprayers/tractors/harvest bins which can result in cut, split or bruised fruit (affecting your packout, storage and profit).
- Check your sprinkler heads – fruit stain caused by irrigation water can be problematic. Irrigation heads that are too high, have been broken and/or knocked sideways can result in water spraying vertically or diagonally, wetting the fruit. Water sources that are high in heavy metals such as iron or manganese may therefore cause staining on fruit. This type of stain can be extremely difficult to remove, with clean-up sprays often being ineffective – so prevention is the best option. Prevent this type of stain from occurring in the first place by ensuring irrigation heads are set level and not too high so water is not making contact with fruit.
- If you identify stained fruit on the orchard try dipping some fruit in clean-up spray (at label rates) to see how effective it is at removing the stain. Remember, not all clean-up sprays work the same way – calcium phosphate/phosphoric acid cleaners such as CP Clean are good options for early harvested fruit, but are less effective at removing heavy staining. Tougher stains may require a phosphate buffered lactic acid product such as Jewel Clean LF or KiwiLustre LF – these cleaners act over a period of 2-3 days but typically have some negative impact on leaf condition (so are not typically recommended for use in KiwiStart).
- I also suggest you contact your Grower Services Rep so we can make a plan around harvest – knowing that fruit may be suffering from stain prior to packing is going to provide you with the best possible outcome!
- Enter your fruitset date and spray lines in Spray Diary now – this allows you to run spray diary “test” audits to make sure everything is passing well before harvest (and fix any errors!). Remember to run a “test audit” before your “final audit” – this will let you know if there are any issues with what you’ve recorded. Once you’ve submitted your diary for a “final audit”, your diary is locked and no further changes can be made without contacting Zespri. Feel free to contact me or your Grower Services Representative if you need assistance.
- Keep your sward low otherwise the maturity clearance/residue samplers may refuse to access your orchard.
- Understand the new Zespri Maturity Clearance System (MCS) – attend a Zespri training session (online or in person) on how to use/understand the new Zespri MCS – see the “Upcoming Events” section below for more detail.
Zespri Maturity Clearance System (MCS) – Grower Training Schedule 2021
The Zespri MCS Support Team will take you through the new MCS system and key changes to the clearance process this year. Training content includes login, orchard information setup and management, viewing sample results, and troubleshooting.
Please click the link below to sign up for a session. Online sessions will take place via Microsoft Teams, and in person sessions will be hosted in Zespri’s board room.
- Online sessions – click here to register
- Thursday 15 April 2:00pm – 4:30pm
- In-person sessions – click here to register
- Friday 9 April 1:00pm – 3:30pm
Have a great weekend!