A field trial to assess action thresholds for management of Bactericera cockerelli in main crop processing potatoes at Pukekohe

摘要

A main crop summer potato trial at Pukekohe assessed the damage caused by Bactericera cockerelli, tomato potato psyllid (TPP), and investigated the use of action spray thresholds. Five treatments were used: in-furrow insecticide and weekly blocks of foliar sprays; in-furrow insecticide and one of three different threshold-based foliar spray programmes; and no insecticides. The threshold-based spray programmes used either the number of TPP nymphs per middle leaf or the mean number of TPP adults per yellow sticky trap per week, plus different mode-of-action insecticide rotations. Three treatments resulted in acceptable yield and specific gravity, and a low incidence of zebra chip disease (ZC). These were the weekly treatment and two spray programmes based on a threshold of >3 TPP adults per trap per week where insecticide applications were reduced by 50% compared to the weekly applications.