In 2018, NZ Avocado developed and implemented a plan to support the improvement of quality on all avocados from New Zealand. Below is a summary of the projects within the plan and their status to date.

On orchard

Best practice for the mitigation of fruit rots on orchard

A comprehensive literature review, best practice guidelines and technical worksheets have been developed for the control of fruit rots on orchard. 

Sustainable Farming Fund (SFF) – AvoVantage

The SFF application from NZ Avocado has been successful and aims to reduce the percentage of unsound fruit as well as further develop best practice guidelines based on practical, sustainable and effective disease management strategies for the management of fruit rots on orchard. The work is being led by Plant & Food Research and will begin in July 2019 for a duration of three years.

Fungicide registration trials

Fruitfed began a trial investigating the efficacy of two alternative fungicides (both of which are under non-disclosure agreements) in 2018. The results from these trials will be available March 2019.

Registration trials for Amistar ® (active ingredient azoxystrobin) and Timorex Gold ® (active ingredient Tea Tree oil) are underway and will be completed by November 2019. Application for registration with ACVM will be dependent on efficacy results from the trial. If registration is to proceed, it is expected to be completed by the end of 2020.

Calcium – nutrition and quality

Interviews with various industry consultants has identified different views across the industry on calcium application practices and recommendation.

Post Harvest

Post harvest supply chain temperature

Application for a “Startup” Callaghan grant was submitted and accepted in January 2019 and will be completed in April 2019. This funding will be used to characterise the environmental conditions from harvest to in-market customer and attempt to link incidence of avocado chilling injury with particular practices through the supply chain. The grant will assist in collecting useful supply chain information that will guide the development of the major project and give appropriate insight into factors that will need to be considered in developing solutions to chilling injury.

AgMARDT controlled atmosphere (CA) trial

A trial investigating the harvesting of early fruit and storing in CA for 6-8 weeks, was undertaken at the end of 2018. The project is being headed by Jem Burdon from Plant & Food Research and co-funded by AgMARDT. Preliminary results from the trial do not look promising. A final report will be available in June 2019.

Post harvest fungicide efficacy trial

A postharvest trial was undertaken in December 2018, investigating the effect of postharvest applications of “Generally Regarded as Safe” (GRAS) fungicides on the expression of fruit rot fungi in New Zealand Hass avocados. Both products have shown efficacy in other horticultural products overseas against some of the same fungi that cause fruit rots in avocados from New Zealand. Results will be available in March 2019.

Discussions are underway with agrichemical company Syngenta about obtaining registration of the postharvest fungicide Graduate-A® (active ingredients azoxystrobin and fludioxonil) use in New Zealand. Use is likely to be limited due to residue limits of our export markets.

Waterblaster review

In 2018 a waterblaster trial investigating the effect of a 95% commissioned water blaster on lenticels was undertaken. Results showed that:

  • Running fruit through the waterblaster set at the 95% efficacy commissioned rate did not statistically affect the external quality of dry harvested fruit (non-turgid) but had a statistically significant effect on the external quality of the wet harvested fruit (turgid fruit).
  • Turgid fruit, as demonstrated by the roll test, were significantly more susceptible to lenticel damage compared to non-turgid fruit, even when not exposed to the water blaster treatment.
  • Running turgid fruit through the water blaster significantly increased the amount of lenticel damage.

In collaboration with the Packer Forum we continue to review the process in the packlines to identify changes to quality.

A procedure for water quality testing has been developed for the packhouses with the recommendation that packhouses monitor their water quality throughout the season.

Impact sensor for the packline

An impact sensor is available to provide real-time measurements of impact on the packline. It is designed to replicate an avocado on the line and may provide opportunities for improvement. NZ Avocado and the Packer forum are working collaboratively to identify where and how this will fit into our quality monitoring strategy.

Best practice harvest

A review of previous work involving harvesting and fruit quality has been undertaken and harvesting best practice guidelines have been published in the September 2018 Avoscene and are available in the Grow section on this website.