This is the problem:
Extended periods of dry weather conditions mean that vineyards often show show damage symptoms from salt (sodium and chloride). As soil moisture reduces vines pull water harder from the soil (plants create a negative pressure from the leaves to the roots - pulling harder means a higher negative pressure).
As the vines pull harder they take up more salt with the water. Eventually the concentration in the leaves becomes toxic and the leaves 'burn.' Sodium and Chloride levels in the developing fruit also increase which can have a detrimental effect on wine quality. Look for leaves that are small, curled downwards and browned at the edges on most shoots of the vine (below).
Do you have a solution?
Yes, we can craft a strategy using some or all of these below, how many of these are practical in your situation? We think the strategies in bold text are practical in almost all situations.
• Schedule irrigation applications to ensure adequate leaching of salts.
• Mound soils with limited drainage or shallow depth.
• Increase soil organic matter both inseason, using humic acid, and post harvest by suing compost. Organic matter helps buffer soil salinity by binding to sodium.
• In the long term replace own-rooted vines with saline-resistant rootstocks to minimise the effects of salinity.
• Mulch the under-vine row to reduce surface evaporation and minimise surface salinity.
• Shandy saline water with a less saline source of water (recycled water mixed with bore water etc).
• Reduce the amount of saline water applied to the vines i.e. Partial Rootzone Drying (PRD).
• Take water, soil and tissue tests. Monitor salinity to help make management decisions.
