AVOCADO TECH TIP

Welcome to our regular market update for avocado growers. Latest update: Early December 2020

Pest situation: 

It is now  the end of November, fruit set, or lack thereof, is now becoming evident. 

  • Very little change in insect pest pressure during the past month.
  • Insect pressure is in line with long term trends.
  • Small spike in leaf roller and we would expect this trend to continue with the regular rains and time of the year.
  • Six Spotted Mite risk is large with many orchards infected from Athenree to Opotiki (see chart).  Levels in some orchards are now very high.  The problem does appear to worse on young orchards (1-3 years olds).

Key AvoGreen and insect pressure points from the past two weeks:

  • Leaf roller pressure is showing signs of starting to build.  
  • Thrips pressure is very low
  • Six spotted mite pressure is present in many orchards and there is severe leaf defoliation in many young orchards.

Spray recommendations:

Leaf roller

According to the monitoring data leaf roller caterpillar levels are low but caterpillars were recorded on a small number of orchards.  

  • Growers are encouraged to start looking for leaf roller in the orchard
  • Contact the office if you need any guidance.
  • Some growers need to think about spraying for leaf roller as low levels are appears in the monitoring results
  • If you do need to spray please review with holding periods if you still have fruit for export
  • Methoxyfenozide (Prodigy) is a good spray to consider as a first spray on new season fruit if it is the only pest as it fits with most IPM programmes and is considered “soft” on predator insects
    • Do not mix with oil 
    • Make sure flowering is over as Prodigy is “moderately” toxic to bees
  • https://www.corteva.co.nz/products-and-solutions/crop-protection/prodigy.html

Thrips

Thrips pressure is low.

  • Contact the office if you need any guidance but there should be no reason to spray based on monitoring data (with possibly four to five exceptions in the past fortnight).   

Mites   

Mite pressure is very high in some orchards.  The avoGreen monitoring data suggests not all orchards are affected  but most are and in some cases infestation is severe (average infestation is 10-11%).  Young orchards are very high risk – go out and monitor and premature leaf drop is sign to probe harder.

  • Please talk to us before spraying.  If you do need to spray review with holding periods if you are still picking.
  • The best option is to wait till bees out and  flowering has over and apply Abamectin.   Apply Abamectin plus a “super spreader” when there is sufficient new season leaf flush.
  • Avid/Abamectin/Apostile/Abamax/Verdex/etc:
    • Very toxic to bees.  Accoring to the label Avid cannot be applied to avocado trees in flower if the flowers are likely to be visited by bees.  Therefore night spraying is not legal.
    • Best to use in spring on young full or partially expanded flush and before mite levels are very high.  Go hard and go early!
    • Remember there is a maximum use of three Abamectin sprays per year.
    • https://www.syngenta.co.nz/product/crop-protection/insecticide/avid

Notes: 

  • Your pack out reports may show a record of scale on your fruit found in the pack house.  You are notified of this as it’s a justification to spray.  Please talk to us if you want to use this justification to spray for scale. 
  • This is an important time for fruit quality both blemish and rots.  Leaf roller moves from flush to young fruitlets and from mid-summer fruitlets become infected with latent infections.  Make sure you have a plan for fruit quality for the coming season.

Legal requirements

There is a legal requirement not to apply class 9.4 (toxic to insects) if:

  • bees are foraging on the crop
  • non target plants (flowering shelter belts or orchard floor plants) that are likely to be visited by foraging bees are in flower or part-flower.

If you require more information or would like to talk over any of the issues covered in this AvoGreen Update please contact Daniel (0274866969), Katherine (0272119181), Anne (0276126636) or Jonathan (0279733513).