Key points
- Field trials were established in Pukekohe, Manawatu and Canterbury to develop regionally focused pest management strategies, initially focussing on tomato potato psyllid (TPP) and zebra chip disease.
- The accumulated degree days trigger used in treatment 2, has not worked in Canterbury for two years in a row. This is in contrast to trials in the North Island where these treatments work well. This season, a refined trigger will be tested in Canterbury.
- Zebra chip disease incidence can be highly variable in a crop. It is determined by TPP distribution in a field and how many psyllids carry the bacterium that causes the disease.
- Spray timings seem to be quite important to manage zebra chip disease.