Con­trol­ling TPP on cap­sicums


The pres­ence of species of quar­an­tine im­por­tance re­sults in costly methyl bro­mide fu­mi­ga­tion, which also sig­nif­i­cantly re­duces out-turn qual­ity of cap­sicums. In some coun­tries, fu­mi­ga­tion prior to ex­port is manda­tory for ac­cess; in oth­ers fu­mi­ga­tion may be re­quired at the bor­der.

Dur­ing the past year Plant & Food Re­search (P & F R) has been man­ag­ing a pro­ject to find al­ter­na­tive treat­ments to methyl bro­mide for cap­sicum ex­ports to Aus­tralia and fu­ture ex­ports to the United States.

The pro­ject, which is funded by Veg­eta­bles NZ Inc. and Plant & Food Re­search’s veg­etable Core Fund­ing, is now in its se­cond phase.

On com­ple­tion of the first phase, four op­tions have been pro­posed for the con­trol of tomato potato psyl­lid (TPP) on cap­sicums:

Op­tion 1: Ethyl for­mate (Va­por­mate) tar­get­ing adults and nymphs (if new in­for­ma­tion demon­strat­ing that eggs can­not sur­vive on cap­sicum fruit is ac­cepted). Op­tion 2: Ethyl for­mate and low TPP preva­lence in a sys­tems ap­proach.

Op­tion 3: Hot wa­ter treat­ment and ethyl for­mate com­bi­na­tion treat­ment.

Op­tion 4: Sys­tems ap­proach – low pest preva­lence, hot wa­ter treat­ment and ethyl for­mate.

Plant & Food Re­search also sees the po­ten­tial of high pres­sure wash­ing to re­move TPP eggs (and hatched nymphs) as an op­tion for a `sys­tems ap­proach’ in the fu­ture, if re­quired.

Al­though a trial last year demon­strated that hot wa­ter dips were ef­fec­tive against TPP eggs, the in­dus­try would pre­fer us­ing hot wa­ter drench­ing (low pres­sure spray­ing over fruit on rollers) or hot wa­ter brush­ing (low pres­sure spray­ing over brushes).

It is an­tic­i­pated that the ef­fi­cacy of all of the in­di­vid­ual com­po­nents of a po­ten­tial sys­tems ap­proach against TPP eggs and nymphs will be known and spe­cific com­bi­na­tions ac­cept­able to the in­dus­try de­ter­mined af­ter feed­back from the Aus­tralian Govern­ment Depart­ment of Agri­cul­ture and Wa­ter Re­sources will be tested next sea­son.

Two tri­als are now un­der­way:

Trial 1: A com­par­i­son of the ef­fi­cacy of hot wa­ter dips, drenches or brushes against TPP eggs and nymphs Hot wa­ter dips have been found to be an ef­fec­tive means of con­trol­ling sur­face pests on fruit af­ter har­vest and are of­ten used as part of a sys­tems ap­proach to con­trol­ling posthar­vest pests. Hot wa­ter treat­ment of cap­sicums is ef­fec­tive at killing pathogens that cause sur­face de­cay while main­tain­ing fruit qual­ity. Pre­vi­ous re­search has found that a high pres­sure wash­ing treat­ment us­ing 75 psi (pounds per square inch) fol­lowed by a 30-se­cond hot wa­ter drench at 55°C (a heavy shower of hot wa­ter) and hot air dry­ing re­sulted in bet­ter qual­ity cap­sicums than the stan­dard com­mer­cial treat­ment dip­ping in a fungi­cide.

_____________________________________________________________ The pres­ence of pests such as aphids, mealy­bugs, thrips, mites and psyl­lids on cap­sicum fruit can cause mar­ket ac­cess is­sues. The tomato potato psyl­lid, ( is a par­tic­u­larly se­ri­ous pro­duc­tion and quar­an­tine pest and since its ar­rival in New Zealand has re­sulted in more strin­gent phy­tosan­i­tary re­quire­ments for some mar­kets.

Veg­eta­bles New Zealand Inc.

Se­nior Busi­ness Man­ager

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