Benefit of Fungicide Treatment after Trunk Renewal of Vines with Different Types of Esca Necrosis

Abstract

Vines cv. Trebbiano d’Abruzzo grown in three vineyards located in Teramo Province, Abruzzi, Italy, severely
affected by esca proper, were subjected to trunk renewal and thereafter treated with triazoles and fosetyl Al
fungicides, applied either by trunk injection via syringe, or by ground injection via injector pole. Trunk renewal, by
cutting the trunk, made it possible to determine the extent and type of wood deterioration on the residual trunk
portion, where it was found that rotted and discoloured wood often still remained. Fungicide treatment was begun in
1995, when trunk renewal was performed, and was continued until 1998; after this the vines continued to be monitored
for a further 4 years until 2002. In 2002, vines that had received trunk injections after trunk renewal were in
better vegetative condition than vines without such injections, with full yield and lower mortality. Cyproconazole was
particularly effective when trunk injected, but was not effective when injected into the ground. A possible explanation
for this is given. Moreover the effect that the severity of the wood necrosis observed at the time of trunk renewal
had on treatment effectiveness was evaluated. The current lack of similar trials and studies in other vineyards
makes standardisation of control methods difficult; any positive effects may have been due to concurrent factors such
as cultivar vigour, or peculiar environmental or cultural conditions.