We’re entering 2023, and if you’re keen on creating New Year’s resolutions each year, then you should also be creating resolutions for your vines to ensure they grow healthier and live longer.
These resolutions are for growers of all experience levels, and I am confident they will be easier to keep than the fitness goals we all set and then ditch each new year.
Resolution #1: Understand the pH of your Spray Water
- The pH and hardness of your water can drastically affect how well your spray products work. Water pH impacts spray efficacy in all categories, whether it’s a fungicide, insecticide, or herbicide.
- Too high of a pH in your spray water can cause a reaction known as alkaline hydrolysis resulting in the degradation of the spray product you add to your tank. On the other hand, excessively low pH or acidic water can also render some spray products less effective or even result in burns on your leaves.
- The pH of your spray water should be tested at the source from your well. If using products to condition or change the pH of the spray water, always test the water again after making adjustments to be sure you hit your target before adding the spray product to the water.
- Test the pH and the hardness of your spray water several times over the course of the season since the water chemistry can change throughout the season. Most products function best at a range of about 5.5 to 6.5 pH. Be sure to read the label of all products and conditioners thoroughly and remember that the label is the law!
Resolution #2: Irrigation Distribution Uniformity
- Uniform water distribution is absolutely critical if you’re injecting any nutrients or any labeled product into your irrigation system. If the vines on the far end of your irrigation lines are getting less water and less fertilizer, they will stray further and further away from the status quo. This results in vine decline, uniformity problems, and yield issues. Without uniformity, your vines will grow unevenly impacting your yield and crop uniformity and costing you potential revenue from low-producing areas of your vineyard.
- Distribution uniformity (DU) is expressed as a percentage of complete or 100% uniformity. Ideally, your percentage in your vineyard should be above 85%. Anything below 70% is considered poor uniformity.
- To measure, use a handheld pressure gauge and check the pressure near the entry point of the well water or the inlet manifold. Test it again someplace in the middle of the line halfway downstream and then test it far downstream near the end of the line because that’s where pressure issues are usually picked up. For the second part of testing, run your irrigation and capture water under a series of emitters at various distances from the well source using 16 to 28 measuring points at each location.
- The most common factors affecting DU are clogs or roots in the lines, changes in pressure caused by pipe friction, spacing of emitters or lack of pressure-compensated emitters, or poorly adjusted pressure regulators.
Resolution #3: Monitor Your Soil Moisture
- Installing irrigation is only half the solution to ensuring your vines have adequate water. To effectively irrigate, you need to monitor your soil moisture throughout the season. This helps you understand if you’re applying too much or too little water, both of which are important for real-time decision-making throughout the season.
- The use of soil moisture probes with multiple depth sensors will help you understand when you need to irrigate and how long the irrigation set should be to get to the proper depth for your root zone. Probes will also help you understand the impact of a rain event and whether or not you need to keep watering after that rain event to create a full irrigation set, and how long after the rain until you need to start irrigating again.
- Soil moisture probes also help you ensure that anything you apply via your irrigation system reaches the depth needed for maximum root uptake so that you do not miss the root zone by being too shallow with irrigation or by irrigating too long and pushing well past the root zone.
- Most modern sensor systems can monitor soil moisture remotely. So if you’re away from the vineyard, or if you’re a vineyard manager trying to keep track of workers and whether or not they’re doing their job with irrigation, those remote sensors will help you make sure the job is getting done.
Resolution #4: Nutrient Sample at Bloom and Verasion
- If your vines are at least three years old, you need to be tissue sampling every season at bloom and veraison. If you don’t sample, you are really just guessing about critical fertilization decisions which usually means you either are wasting money by adding nutrients that aren’t needed or your vine health and the quality of your fruit is suffering because of missing or imbalanced nutrients.
- Sampling at bloom gives you the insights needed to be able to address nutrient issues prior to veraison and harvest to improve the quality and uniformity of your grapes.
- Sampling at versaion gives you a brief window to intervene prior to harvest on some issues and shows you what your vines need post-harvest to give you good production for the next season. Consider veraison sampling to be the annual check-up of vine health in your vineyard.
- The optimum time for bloom nutrients sampling is when your earliest variety is at approximately 25% to 50% bloom, so be sure to get this on your calendar near your historical dates. Veraison sampling should start when the earliest red variety on your site is about 25% to 50% through color change or veraison, or roughly around the point of berry softening for white grapes.
Resolution #5: Prune for Vineyard Longevity
- The longevity of a vineyard depends on how you prune and where you make cuts on your vines each year. Avoid large diameter cuts, especially close to an area that is conducting nutrients and water to other areas of the plant. Making large diameter cuts close to trunks or cordons will also cut the circulation out of the vine and this could be an entry point for diseases and for cracking and freezing.
- You can also position pruning shears in a way that reduces unnecessary dieback on 2-year-old or older wood when it becomes necessary to renew spur positions and remove older fruiting canes.
- For new growers, training young vines in a stepwise fashion reduces the vines’ propensity to over-crop. This also ensures adequate and well-spaced positions for future spurs or canes.
If you want to learn more about how to be a better grape grower, check out www.vineyardundergroundpodcast.com/vu009.