Putting your vines to bed for winter | Vine Talk
By Scott Mathew, Syngenta Technical Services Lead
With the focus at this time of year on winemaking, it’s easy to overlook vines and vine health. It’s something that can come back to haunt you next spring if you’re not careful.
Inadequate water and nutrition at the end of the season can result in low carbohydrate storage, lack of stored nutrients and dry woody tissue. That can lead to winter injuries, uneven bud break, poor and/or uneven shoot growth and even inferior fruit set.
Ideally, to boost carbohydrate reserves you will want to have a healthy, photosynthesising canopy for as long as possible combined with good crop protection to ensure pests and diseases are not eating into next year’s crop yield.
Post-harvest vineyard clean-up and management is important as we prepare vines for dormancy and set up shoot and fruit growth next spring.
Pests and diseases
With post-harvest disease and pest management, keep an eye on the mildews and any mites that may arrive late in the season. This is particularly important for young vines as late season damage can predispose them to frost or cold damage in the winter.
In the post-harvest period it is important to limit the possibility of fungal infections and insect pressure by taking general clean-up measures, including keeping the surrounding areas free of weeds and tall grass and pruning to remove any mummified bunches. If you have high fungal pressure post-harvest, the economics of fungicide application are debatable. Consulting your local agronomist before you spray is a good idea.
After harvest the vines will continue to take up nutrients and minerals, photosynthesize and store carbohydrate reserves in the roots and trunks. It is an important time for nutrient uptake to supply the needs from bud-burst to flowering. Australian studies have revealed vegetative growth and yield is directly linked to the post-harvest nutrient management of the grapevines. The period between harvest and leaf fall is one of the best times for nitrogen uptake. Soil and tissue analysis will be the best guides for correct fertiliser rates.
Finally, don’t neglect post-harvest irrigation. The soil needs to be moist for the vine roots to extract nutrients and keep the leaves hydrated for photosynthesis for accumulation of plant reserves.
Syngenta is a sponsor of Australian and New Zealand Grapegrower & Winemaker. Vine Talk first appeared in the March 2019 edition (No. 662).