Olive Oil Commission of California Funds Research

The Olive Oil Commission of California (OOCC) has set aside $170,250 for research and related ini­tia­tives for the state’s olive oil sec­tor in the 2019/20 fis­cal year.

The major­ity of this fund­ing from the OOCC, which was formed to sup­port research for the California olive oil indus­try, will go to the UC Davis Olive Center, which is set to under­take many of the new research projects.

This includes $14,849 for research into olive anthrac­nose – a fun­gal dis­ease that attacks olive fruit – in California and a $15,000 research project on the epi­demi­ol­ogy and man­age­ment of olive knot, which causes growths on olive trees.

“Olive knot is one of the most preva­lent dis­eases for high and medium-den­sity olives for oil,” Chris Zanobini, the exec­u­tive direc­tor of the OOCC, told Olive Oil Times. ​“If we can effec­tively min­i­mize the spread or the pres­ence of the dis­ease, as well as have effec­tive tools to com­bat it, we can ensure the future growth of high-qual­ity olive oil from California.”

“Anytime we can bet­ter under­stand issues that are affect­ing our qual­ity and pro­duc­tion, it is going to ben­e­fit all olive oil pro­duc­ers in California,” he added.

OOCC research coor­di­na­tor Tyler Rood said olive knot is one of the most eco­nom­i­cally sig­nif­i­cant dis­eases for olive grow­ers in the state.

“Infection may lead to tree defo­li­a­tion, dieback and reduced tree vigor, which ulti­mately low­ers fruit yield and qual­ity,” Rood told Olive Oil Times

He added that the OOCC and California Olive Committee (COC) are jointly fund­ing a sep­a­rate project to pro­vide olive grow­ers with the knowl­edge and tools to com­bat the dis­ease.

Jim Adaskaveg, a plant pathol­o­gist at UC Riverside who has inves­ti­gated the epi­demi­ol­ogy of olive knot, is now using this knowl­edge to develop and pro­mote inte­grated man­age­ment strate­gies for the con­trol of the dis­ease in California.

Rood said Adaskaveg has shown that olive knot is caused by an oppor­tunis­tic pathogen, Pseudomonas savas­tanoi pv. Savastanoi, which is more preva­lent in damp con­di­tions and ​“can infect olive [trees] through wounds caused by mechan­i­cal injuries from prun­ing and har­vest.”

To reduce the rate of new infec­tions, Adaskaveg pro­motes the prun­ing and removal of wood infected with olive knot dur­ing dry peri­ods, as well as the san­i­ti­za­tion of prun­ing and har­vest equip­ment fol­low­ing expo­sure to olive knot.

“Jim has gone so far as to eval­u­ate new san­i­ta­tion mate­ri­als,” Rood said. ​“Namely qua­ter­nary ammo­nium.”

He added that qua­ter­nary ammo­nium is highly effec­tive for san­i­tiz­ing prun­ing and har­vest­ing equip­ment, and is non-cor­ro­sive.

Rood said cop­per-based bac­te­ri­cides, which are widely used in both con­ven­tional and organic agri­cul­ture, is the only avail­able and effec­tive foliage treat­ment for the con­trol of olive knot.

Adaskaveg also eval­u­ates the effec­tive­ness of cop­per alter­na­tives aimed at reduc­ing depen­dence on the metal and pre­vent­ing wide­spread Pseudomonas savas­tanoi pv. Savastanoi resis­tant to cop­per. He will present his annual find­ings at California Olive Oil Day, which is funded by the OOCC, on March 5, 2020.

Meanwhile, the OOCC research project on the occur­rence and dis­tri­b­u­tion of olive anthrac­nose in California is led by Florent Trouillas, assis­tant coop­er­a­tive exten­sion spe­cial­ist at the UC Davis plant pathol­ogy depart­ment.

Rood said this project aims to iden­tify which species of Colletotrichum fun­gus are asso­ci­ated with olive anthrac­nose in California, and if these species cause dis­ease to the main cul­ti­vars found in the Golden State.

He said symp­toms resem­bling olive anthrac­nose have recently been iden­ti­fied in olive orchards in the Sacramento Valley.

“While strains of Colletotrichum are known to cause olive anthrac­nose through­out the world and dis­ease of other com­modi­ties found within California,” Rood said. ​“The occur­rence of olive anthrac­nose in California remains unknown.”

“Given that olive anthrac­nose poses a threat to olive orchards world­wide, and neg­a­tively impacts yields and qual­ity of olive oils made from affected fruit, it is impor­tant that we as an indus­try act and deter­mine the occur­rence and dis­tri­b­u­tion of olive anthrac­nose in California,” he added. ​“Documenting the occur­rence and dis­tri­b­u­tion of the dis­ease in California will allow the indus­try to begin devel­op­ing man­age­ment pro­to­cols and reg­is­ter­ing new mate­ri­als for con­trol of the dis­ease.”

“Should Colletotrichum not be iso­lated and iden­ti­fied from symp­to­matic tis­sues sam­pled from sur­veyed oil olive orchards,” Rood fur­ther explained, ​“Florent will iden­tify and record which pathogens are caus­ing the symp­toms observed in orchards. These efforts will help the indus­try to record the geo­graph­i­cal and sea­sonal occur­rence of dis­eases of oil olives within the Central Valley.”

Another research project funded by the OOCC for the 2019/20 fis­cal year is a $30,000 project to update the olive pro­duc­tion man­ual. In addi­tion, the OOCC is fund­ing a $6,500 project to iden­tify areas of irri­ga­tion man­age­ment in California that lack suf­fi­cient research.

They are also fund­ing a $7,500 research project on pea­cock spot – jointly funded with the COC – and a $10,000 project on the nutri­tional needs of olive orchards.

Additionally, the OOCC is invest­ing $7,500 to com­pile a data­base to ensure their purity stan­dards are in line with the char­ac­ter­is­tics of extra vir­gin olive oils pro­duced in the state; $42,850 for a sur­vey of the qual­ity of California olive oil; and $11,250 to eval­u­ate the impact of the OOCC’s manda­tory sam­pling and test­ing on the qual­ity of the state’s olive oil.

Besides these research projects, the OOCC funds California Olive Oil Day, which was launched two years ago and gives grow­ers the oppor­tu­nity to inter­act with researchers at the Olive Center.