Training Technique May Have an Effect on Permanent Cordon Longevity

Background and goals A trial was set up at two vineyard sites to quantify the effects of different permanent cordon training techniques on indicators of vine health and productivity. One treatment involved wrapping developing cordon arms tightly around the cordon wire, a practice common in some winegrowing regions.

Methods and key findings Results suggest that the constriction applied by the tight wrapping may have had a negative effect on vegetative growth. These include reduced circumferences of tightly wrapped cordons in the later seasons of the trial at one site, as well as lower distal pruning weights. Other measurements, including plant area index, do not indicate that there was a reduction in the vegetative growth of tightly wrapped cordons and suggest that cordons trained around two parallel cordon wires in a loose, s-shaped bend suffered from the greatest reduction in plant tissue area. Measurements of fertility, carbohydrate status, grape chemistry, and yield components did not indicate major differences between the applied training methods.

Conclusions and significance One of the purported benefits of tightly wrapping arms around the cordon wire is minimization of the risk of mechanical damage by means of increased canopy stability. In contrast, in one year of this trial, more mechanical damage was observed in tightly wrapped cordons than other training methods, suggesting that the method was unsuccessful in mitigating this risk. It is likely that the differences observed between the applied treatments would continue to become more pronounced with further observation because cordon constriction is a condition that becomes progressively worse over time.