Av­o­cado Up­date Re­search de­liv­ers for grow­ers

Col­lab­o­ra­tion is the theme of our re­cent re­search bul­letin and it con­tin­ues to drive our suc­cess as an in­dus­try.

The Orchardist - - Contents - Marisa Till is re­search man­ager for NZ Av­o­cado

The bul­letin pro­vides a snap­shot of cur­rent re­search. With this ar­ti­cle are de­tails of some of the ex­cit­ing re­sults emerg­ing from our re­search port­fo­lio. This re­search de­liv­ers to our grow­ers and other in­dus­try stake­hold­ers the op­por­tu­nity to con­trib­ute to the on­go­ing work with the aim of max­imis­ing the im­pact our pro­gramme has for our in­dus­try.

Our re­search pro­gramme aims to in­crease both yield, in tonnes per hectare, and con­sis­tency of yield across sea­sons. We are tasked with mea­sur­ing the im­pact of the re­search pro­gramme on those fac­tors. Across the av­o­cado in­dus­try, we bench­mark the per­for­mance of each or­chard on an an­nual ba­sis and record the im­prove­ment in that per­for­mance. We record or­chard per­for­mance as “best”, “good”, and “stan­dard”, based on the four-year av­er­age yield and con­sis­tency of yield. The chart with this ar­ti­cle demon­strates that more than 50% of our or­chards now per­form in the “good” and best” cat­e­gory, from un­der 30% in 2010-14.

NZ Av­o­cado is in­volved in a range of re­search aimed at de­liv­er­ing tools for our grow­ers to help im­prove the con­sis­tent pro­duc­tion of qual­ity fruit. Our re­search team works col­lab­o­ra­tively with sci­en­tists from a range of in­sti­tutes in­clud­ing Plant & Food Re­search and Waikato Uni­ver­sity with the help of fund­ing from the min­istry for­merly known as the Min­istry for Pri­mary In­dus­tries, Min­istry of Busi­ness, In­no­va­tion and Em­ploy­ment and AGMARDT. With these joint ef­forts and com­bined ex­per­tise, we are mak­ing great progress into not only un­der­stand­ing the needs of an av­o­cado tree bet­ter, but also de­liv­er­ing tools that grow­ers can use in their or­chard man­age­ment prac­tices to im­prove their yields. Some of the key high­lights that are emerg­ing from this re­search in­clude:


The amount of wa­ter used by an av­o­cado tree, both young and ma­ture, has been quan­ti­fied in the Bay of Plenty through mon­i­tor­ing the sap flow in the trunk of the trees. This has led to the gen­er­a­tion of a crop fac­tor re­lat­ing av­o­cado tree wa­ter use to ref­er­ence evap­o­tran­spi­ra­tion. This al­lows NZ Av­o­cado to pub­lish wa­ter use ta­bles fort­nightly to grow­ers that can be used to in­form ir­ri­ga­tion strate­gies. This work is cur­rently ex­pand­ing into our other ma­jor grow­ing re­gions, Whangarei and the Far North, to fur­ther im­prove the qual­ity of the data and ex­pand it to the dif­fer­ent soil types and con­di­tions.


Av­o­cado trees have a ten­dency to bear ir­reg­u­larly, a big crop one year fol­lowed by a small or even no crop the fol­low­ing year. This pro­vides sig­nif­i­cant chal­lenges, not only for grow­ers but also through­out the value chain – pack­ers, mar­keters and even our av­o­cado loving con­sumers. A sig­nif­i­cant part of our re­search pro­gramme is aimed at de­vel­op­ing tools to ad­dress this vari­a­tion be­tween sea­sons. One of these tools is flower

prun­ing to bal­ance crop load in the ‘onyear’ or the big crop year.

The early in­di­ca­tions from the flower prun­ing tri­als are that flower re­moval of up to 60% as early as Oc­to­ber does not trans­late to the same drop in fi­nal crop – in fact, it is only about a 10% de­crease com­pared with un­pruned trees. This flower prun­ing also re­sults in larger av­er­age size fruit and most im­por­tantly has an im­pres­sive im­pact on re­turn flower the fol­low­ing sea­son. We are an­tic­i­pat­ing har­vest­ing the sec­ond year’s crop in Novem­ber; this will al­low us to quan­tify the im­pact on the re­turn crop from flower prun­ing in an on-year.


Our canopy-man­age­ment work­ing group has iden­ti­fied and char­ac­terised the prun­ing strate­gies of some of the in­dus­try’s top pruners. Al­though many of these prun­ing strate­gies dif­fer slightly in their ex­e­cu­tion, there are some key prin­ci­ples that fea­ture through­out. We have pro­duced an an­i­ma­tion high­light­ing these prin­ci­ples avail­able through our web­site.

The key prin­ci­ples in­clude prun­ing to max­imise light in­ter­cep­tion – this is key as grow­ing av­o­ca­dos is all about har­vest­ing light. Prun­ing to en­sure easy ac­cess for pick­ers and spray­ing al­low­ing for bet­ter pen­e­tra­tion and cov­er­age. Prun­ing to cy­cle wood, en­sur­ing that there is al­ways wood com­ing through to pro­duce the fol­low­ing sea­sons flower. Prun­ing to max­imise the health of the tree in­clud­ing balanc­ing the vol­ume of the canopy to the abil­ity of the roots to pro­vide for it.


Leaf roller dam­age to av­o­cado fruit causes it to be re­jected for ex­port. One tech­nol­ogy that is show­ing prom­ise for the con­trol of our leaf roller species is mat­ing dis­rup­tion. Mat­ing dis­rup­tion uses pheromones unique to the key species we are tar­get­ing to dis­rupt the abil­ity of males to find a mate. A three-year Sus­tain­able Farm­ing funded project de­vel­op­ing a unique blend of pheromones is en­ter­ing its sec­ond year of tri­als. The tri­als are us­ing pheromone dis­pensers to val­i­date the ef­fi­cacy of the pheromone blend to dis­rupt the mat­ing of all our leaf roller pest species and are show­ing some very ex­cit­ing re­sults.

This chart demon­strates that more than 50% of our or­chards now per­form in the “good” and best” cat­e­gory, from un­der 30% in 2010-14.

Marisa Till

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