Developing and assessing different cordon establishment techniques for long-term vineyard management

Aim: The aim of this research is to quantify the impacts of different cordon establishment techniques on vine health and longevity. It is hypothesised that wrapping developing cordon arms tightly around the cordon wire will cause a constriction of the vascular system, becoming worse over time and disrupting the flow of water and nutrients.

Methods and Results: Training methods including wrapping the cordon tightly around the cordon wire, securing the cordon on top of the wire, and weaving the cordon through a plastic clip system, among others were applied to Cabernet Sauvignon and Shiraz grapevines at two commercial growing sites. At one site a length adjustment was performed on canes selected as permanent cordon arms based on their apparent vigour. Areas of assessment include measurements of vegetative growth, canopy architecture, and yield components, as well as physiological measurements including non-structural carbohydrate status and the microscopic examination of xylem morphology. Susceptibility to fungal trunk diseases is also being investigated. Early results indicate a significantly lower concentration of sugar, starch, and total non-structural carbohydrates in cane samples collected from the distal portion of arms woven through the plastic clip system after one growing season. Additionally, measurements of circumference and pruning weight of the intermediate sections of the cordons were significantly greater in vines which received length adjustments than those that didn’t receive adjustments.

Conclusions: 

Measurements of non-structural carbohydrate status suggest that the use of the plastic clip system may be beneficial in promoting the translocation of carbohydrates from the distal portion of the arm to perennial structures for overwintering. The increase in vegetative growth observed in the vines which received length adjustments suggests that this method may be beneficial in encouraging the growth of more numerous, healthy spur positions.

Significance and Impact of the Study: Suitable vineyard management strategies are needed to minimise the occurrence of cordon decline and dead arm symptoms. Understanding the potential benefits of adopting cordon establishment techniques which avoid constriction of the vines’ vasculature will provide vineyard managers with a strategy aimed at improving vineyard health and longevity.