Open AccessOn-farm trials towards reduced insecticides in main crop potatoes in the Waikato Region of New Zealand
Author(s) -
F.H. MacDonald,
P.J. Wright,
Bryan N. Hart,
Lindy F. Guo,
Sophia K. Hunt,
G.P. Walker
Publication year - 2022
Publication title -
proceedings of the new zealand weed and pest control conference/new zealand plant protection/proceedings of the ... national weeds conference/proceedings of the new zealand weed control conference/proceedings of the new zealand plant protection conference
Language(s) - English
Resource type - Journals
eISSN - 0370-2804
pISSN - 0370-0968
DOI - 10.30843/nzpp.2022.75.11749
Subject(s) - biology , crop , toxicology , integrated pest management , hemiptera , agronomy , pest control , pest analysis , horticulture , botany
Tomato potato psyllid (TPP), Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is the vector for “Candidatus Liberibacter solanacearum” (CLso), which causes the serious disease “zebra chip” (ZC) of potatoes. Between 2016 and 2019, a reduced-insecticide approach to control TPP was evaluated. We compared a standard-insecticide weekly spray regime that included Integrated Pest Management (IPM)-compatible insecticides plus JMS Stylet Oil® (JMS) as a wetting agent, with a reduced-insecticide regime where we used the oil on its own on alternate weeks with the insecticide/oil mixtures. Spray programme start dates were determined by: (1) crop scouting; (2) sticky-trap monitoring; and (3) degree-day calculation. Crop scouting combined with a sticky-trap action threshold and degree-day data was an effective method for determining when to start spraying. The most substantial reduction in insecticides was achieved by alternating weekly insecticides with the oil formulation on its own. Sub-samples of TPP from sticky traps situated in the trials tested for CLso confirmed the presence of the bacteria in (commonly known as ‘hot’) TPP throughout the trials. The reduced-treatment approach gave statistically similar levels of ZC to the standard insecticide spray programme.