Spread of prune dwarf and prunus necrotic ringspot viruses in Golden Queen peach in Hawke's Bay and effect on fruit yields

Abstract

Two Golden Queen peach blocks, one propagated from virus-free scions (Block A), the other from non-indexed sources (Block B), were ELISA-tested 5-7 years after planting for prune dwarf virus (PDV) and prunus necrotic ringspot virus (PNRSV). Trees in Block A were 18% infected by PNRSV at year 5 and 60% by year 7, at which time 1% also had PDV. Block B was 100% infected by PNRSV and 9% with PDV by year 5, increasing to 15% by year 7. Between years 5 and 7, salable yield reduced by 18% as a result of PNRSV-infection. Dual infection was likely to have reduced average salable yield by 32% (9.6 t/ha) and gross returns by $4,805/ha.