The Effects of Hot Water Treatment, Hydration and Order of Nursery Operations on Cuttings of Vitis vinifera Cultivars

Abstract

Hot water treatment (HWT) is an effective control for endogenous pathogens, including Phaeomoniella
chlamydospora, in grapevine propagating material. However sporadic unexplained failures of HWT material do
occur. In order to determine the most reliable HWT protocols the effects of HWT at 50°C for 30 min., order of HWT
and storage (store/HWT and HWT/store), and 3 hydration times (0, 4 and 6 h) on root and shoot development and
final condition in dormant cuttings of Cabernet Sauvignon and Chardonnay were evaluated. After incubation callus,
root and shoot development were assessed. Cuttings were potted into cardboard plant bands, grown to marketable
size in a protected environment, and assessed as “A” grade, “B” grade or dead. Callus development in Chardonnay
was affected by an interaction between HWT protocols and hydration times. Callus was least developed in cuttings
hydrated for 15 h and stored before HWT. Callus development in all other treatments was greater (P