Hot Water Treatment, Trunk Diseases and Other Critical Factors in the Production of High-Quality Grapevine Planting Material

Abstract

This review describes the critical factors on which successful grapevine propagation depends and discusses
the steps that can be taken to improve the quality of planting material available to growers. Spasmodic
occurrences of young vine decline and the failure of planting material have plagued the wine industry since the
1990s. The syndrome now described as Petri disease has been identified as the probable cause of many of the
failures, but hot water treatment (HWT) of dormant cuttings (50°C/30 min), for the control of Phaeomoniella
chlamydospora and other endogenous pathogens, has also been implicated in the losses. HWT is known to cause a
temporary switch to fermentative respiration and early retarded growth in treated material, particularly in Pinot
Noir, but the effects of HWT on dormant vine tissue are not yet fully understood. Poor nursery hygiene and poor
storage and handling practices during propagation and planting have also been implicated in vine failure. Demand
for planting material has exceeded supply and there has been little incentive for nurseries to improve their standards.
The quality of planting material could be significantly improved by changing nursery practices, particularly by
discontinuing the practice of soaking cuttings in water, treated or untreated, and by improving general standards of
nursery hygiene and the management of cool rooms. There is a need to develop a set of universal quality standards
for cuttings and rooted vines. Growers also need to be made aware of the characteristics and benefits of high quality
planting material.