This protocol is offered as a guideline for managers of rootstock mother vine blocks, and as a potential research framework for those wishing to reduce Grapevine Trunk Diseases (GTDs) infection in rootstock mother vines and cuttings. Latent GTDs infection in rootstock cuttings is a major source of GTDs contamination in grafted nursery vines and subsequently in new vineyards. The many pruning cuts made at the crown predispose mother vines to infection transmitted to the new shoots via the xylem connection. Direct penetration by epiphytic inoculum on the bark of the shoots/canes can also occur. Older mother vine blocks are typically heavily infected, particularly if not trellised and pruning wounds are not protected. However, availability of effective pruning wound treatments is limited in many countries. The spread of GTDs inocula can be reduced by avoiding sprinkler and flood irrigation, by trellising mother vines, and by spraying fungicides after shoot trimming. Regular trunk renewal also aids in reducing inoculum spread. During harvest, cuttings should not contact the soil. Cuts should be made just below a bud to retain a long internode on the mother vine, and pruning debris should be removed promptly and destroyed. Secateurs should be disinfested regularly and cuttings dipped in a registered fungicide for a maximum of 30 min. Soaking for longer than 30 min is detrimental to the cuttings, increases fungal populations in the basal wounds and softens the bark, favouring penetration by GTDs inoculum. The common practice of dormant bench grafting in nurseries is known to produce more GTDs-symptomatic vines than field chip budding, and likely reasons will be discussed. Improved management for rootstock mother vines is thus more important where dormant cuttings are bench grafted. Here GTDs epidemiology in source blocks is summarised and best practice protocols for mother vine management and pre-grafting stages of propagation suggested.
A protocol proposal for the management of grape vine rootstock mother vines to reduce latent GTDs infection in cuttings
S DI MARCO;
2017
Abstract
This protocol is offered as a guideline for managers of rootstock mother vine blocks, and as a potential research framework for those wishing to reduce Grapevine Trunk Diseases (GTDs) infection in rootstock mother vines and cuttings. Latent GTDs infection in rootstock cuttings is a major source of GTDs contamination in grafted nursery vines and subsequently in new vineyards. The many pruning cuts made at the crown predispose mother vines to infection transmitted to the new shoots via the xylem connection. Direct penetration by epiphytic inoculum on the bark of the shoots/canes can also occur. Older mother vine blocks are typically heavily infected, particularly if not trellised and pruning wounds are not protected. However, availability of effective pruning wound treatments is limited in many countries. The spread of GTDs inocula can be reduced by avoiding sprinkler and flood irrigation, by trellising mother vines, and by spraying fungicides after shoot trimming. Regular trunk renewal also aids in reducing inoculum spread. During harvest, cuttings should not contact the soil. Cuts should be made just below a bud to retain a long internode on the mother vine, and pruning debris should be removed promptly and destroyed. Secateurs should be disinfested regularly and cuttings dipped in a registered fungicide for a maximum of 30 min. Soaking for longer than 30 min is detrimental to the cuttings, increases fungal populations in the basal wounds and softens the bark, favouring penetration by GTDs inoculum. The common practice of dormant bench grafting in nurseries is known to produce more GTDs-symptomatic vines than field chip budding, and likely reasons will be discussed. Improved management for rootstock mother vines is thus more important where dormant cuttings are bench grafted. Here GTDs epidemiology in source blocks is summarised and best practice protocols for mother vine management and pre-grafting stages of propagation suggested.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
