Impact of covered structures on PsaV in kiwifruit vines

Abstract

Trials have been established in three Bay of Plenty kiwifruit orchards to determine the impact of blockscale breathableplastic covers on the progression of PsaV (Pseudomonas syringae pv actinidiae) in preinfected established vines and in newly grafted uninfected plants On each orchard there were three replicated covered areas each spanning four rows and five bays with the uncovered control areas adjacent Two sites with established previously infected vines showed little or no reduction in the expression of disease relative to that observed in vines in uncovered control areas No major progression of disease was observed in one of these orchards In the second there was widespread expression of PsaV symptoms postgirdling irrespective of whether they were covered or not In the third orchard uninfected grafted vines planted under the canopies of mature infected vines remained relatively disease free compared with similar vines not under cover where numerous leaf spots and secondary symptoms were observed The trials will continue to be monitored