Effects of garlic oil on tomatopotato psyllid

Abstract

Tomatopotato psyllid (Bactericera cockerelli) (TPP) is a vector for Candidatus Liberibacter solanacearum (CLso) a bacterium responsible for causing zebra chip (ZC) a mottled browning discolouration of cooked potato crisps Organic gardeners have long relied on garlic as part of their pestcontrol arsenal Garlic contains sulphur which besides being toxic to pests is also an antibacterial and antifungal agent BioRepel (JH Biotech Inc) is a natural insect repellent made from garlic oil (10 garlic oil) BioRepel has been reported to repel several plant insect pests including aphids leaf hoppers whiteflies and thrips A field trial conducted at Pukekohe to determine the effects of foliar applications of BioRepel garlic oil on TPP nymphs in potato foliage found that garlic oil significantly reduced TPP nymph populations TPP nymph numbers in the unsprayed plots increased during the season from 006 nymphs per leaf on 5 January to 1212 nymphs on 9 March 2010 while on that date the mean number of nymphs per leaf in the BioRepel oil treatment was 305 Further research to determine effects of garlic oil on zebra chip of potato crisps is planned