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