4 July 2019

 

 

 

Avocado on orchard update

July 2019

Market access

  • The Asian markets are an important part of Seeka's export mix and returned good values last season
  • However, to have Asian market access you must have pests under control and fruit as pest-free as possible 
  • The most important pest is scale, fruit must be scale-free to go to South Korea
  • Talk to your CRM before spraying, LynnaireBenGordon or Greg

Maturity

  • Seeka's maturity monitoring final sample collection is underway this week
  • Maturity is early compared to past seasons and only slightly later than last year
  • Early orchards have passed and picked for local market

The orchard 

  • Winter has arrived with sunny but cold days and some frosts
  • As a result, some leaves have lost their green colour and slowly becoming yellow
  • It's important to have good, functional leaves in winter to build starch in the tree for spring flowering
  • Reversing the leaf yellowing is an easy process - apply nitrogen either as a foliar (1% low biuret urea and 0.5% magnesium sulphate to run off is a favourite) or as nitrate like potassium nitrate in a ground application
  • The goal is dark green leaves until trees start to flower
  • There's some winter flowering on trees carrying very little crop, which is normal and nothing to worry about
  • Where flower buds are moving and have broken, the leaves can turn yellow quickly - this is not readily reversible by fertiliser
  • Flower bud break for spring flowering will start about now, with the first few buds swelling
  • Plenty of flower buds are still holding back and will stay tight during cold weather
  • Keep up fertiliser applications to ensure newly developing flowers are well supported and leaves are healthy and frost tolerant
  • So far storm winds have stayed away and fruit drop has been light
  • The greatest risk over the next few weeks is frost, more clear nights are forecasted over the weekend and next week
  • Watch for frosts and run frost protection if needed
  • Structural pruning can be done over winter - removing large limbs to open up trees and reducing tree height is needed
  • Be aware in August and September exposed fruit, branches and limbs can be sunburnt
  • The benefit of good pruning can be lost when the bark on top of tree limbs is destroyed by sunburn
  • White washing (use 50:50 mix of light coloured acylic paint and water) exposed limbs prevents sunburn
  • Fruit sunburn ranges from yellowing of the sunny parts of the fruit to red and black lesions, these fruit are rejects
  • Many growers prevent sunburn by using BudMate, starting in August

Pest management

  • Greenhouse thrips, scale and six spotted mites - AvoGreen findings are at high levels, reflecting mild winter conditions
  • Start considering your annual Paramite application for long-term six spotted mite control, be careful of the withholding times for different markets
  • As an example: If Paramite is applied 4 July 2019 the earliest it would qualify for Korea would be 15 September 2019 (73 days later, withholding time plus a residue test time)
  • In colder weather pests won’t be producing young, get on top of pests now to slow down their increase in spring - only eight weeks away
  • Reducing pest numbers is a good idea before flowering in October as spraying when bees are in the orchard should be avoided
  • Be careful with your spray choices combining oil with other chemicals can result in a long residue tail with the fruit potentially, unexpectedly, failing a residue test
  • Oil alone is fine to apply for scale, thrips and mites, good coverage is essential 
  • Check with your CRM, LynnaireBenGordon or Greg before applying any sprays in case they affect potential harvest dates 
  • The table below shows how many times pest thresholds have been exceeded in the last few weeks for VLS Avogreen monitored orchards

ISO Week

Leafroller Fruit

Leafroller Shoots

Thrips

Scale Fruit

Scale Leaves

Six Spotted Mites

19

1

0

10

4

2

6

20

4

0

23

16

9

12

21

5

0

22

8

6

12

22

2

0

17

5

4

14

23

0

0

17

6

4

11

24

0

0

12

4

19

15

25

2

0

8

8

5

14

26

1

0

19

17

17

19

 

 

No action thresholds have been set for six spotted mites, an index converting mite scores to the equivalent high abundance score of 10% has been used

Avocado Technical Officer

If you have any questions please contact Jonathan.Dixon@seeka.co.nz (021 920247)

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