Canterbury Potato Liberibacter Initiative (CPLI)

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Project Overview

Canterbury Potato Liberibacter Initiative, is a project created and funded by a committee of Canterbury growers and processors, with in-kind support from Potatoes New Zealand.

CPLI was formed in August 2021 by like-minded farmers and industry representatives to combat the devastating impact of the Liberibacter (Lso) bacterium which causes Zebra-chip in potato crops.

The issue is very clear and although the control measures and agronomy of Tomato Potato Psyllid (TPP) has made improvements, the incidence of Zebra Chip in the processing crop has increased and detection levels in potato fields have remained high.

It’s clear that current strategies and chemical programs are not solving or reducing the Zebra-chip impact for growers, seed growers and processors. The CPLI committee all agree there is a major knowledge gap with Lso. Although TPP is the carrier of Lso, Lso is affecting the quality of our potato crop.

October 2021 Update: PNZ-83 CPLI project plan & goals for the 2022 harvest

  • Testing the efficacy of seven contact insecticides through Plant and Food research on TPP with preliminary summary of results available at the end of November. Therefore if any resistance to any of these products is found changes to insecticide strategies can occur for this season. The remaining products will be tested before planting the 2023 crop next year.
  • Weekly text of overview in Canterbury and weekly emails through Potatoes NZ of Growing Degree Day (GDD) Accumulation, there is a historic direct correlation between the earlier the date first psyllid numbers averaging 1 are found on sticky traps and the higher the average Zebra-chip level in that season’s potatoes. Although this is an overview guide for Canterbury you will be able to compare this to your own field sticky trap numbers to see where your crops sit in comparison.
  • Advice on desiccation dates for process crops linked to GDD accumulation or other measure to reduce insecticide use at the end of the season when tuber bulking is complete but crops still have green tops and therefore risk of late season infection of Lso.
  • Winter 2022 review of the past season and results and learnings.
  • Good practice guidelines and fact sheets.

CPLI Newsletter No.2 CPLI Grower Newsletter No.2 Dec-2021

CPLI Newsletter No.1 CPLI Newsletter No.1 Oct-2021

Click here to view CPLI Degree Day Graphs.

Images from PFR