By Kevin Martin
Commodity pressures continue to slam the bulk juice industry. Bulk wine grapes are also facing significant economic pressure. All of this underlines the goals of efficient vineyard as the project participants see technology as one path toward an increase in efficiency that will increase the sustainability of our challenging and competitive marketplace.
This past growing season presented ideal conditions for the economic analysis of variable rate technology. As our experience with sensors has grown, we believe variable crop load management may be the easiest tool to mechanize and commercialize in bulk juice vineyards. The Lake Erie region experienced a significant drought in 2016. This drought impacted vine size at specific sites and on specific soils. For the region and individual growers, it increased crop load variability.
For growers that did not take an active role in crop load management this really showed up in brix accumulation at harvest. Some late season Concords did not reach 15.0 brix and were likely sold for less than $100 per ton. Other early season Concords reached 18.0 brix and were likely sold for $280 per ton. Furthermore, there was also a breakdown of the relationship between brix and yield. The stress created by the drought was highly variable and its impact spilled over into 2017. Some blocks successfully accumulated brix to command premium prices with high yields. Other blocks did not accumulate more than 15.5 brix, despite having modest yields.
It’s not that the region suddenly defied the laws of viticulture, it’s that the drought impacted the vine size side of the crop load equation. This is where the rubber meets the road for the value of sensor technology. Growers will fully admit these patterns were unexpected, not historical and not entirely observed or understood until harvest.
Sensor technology provides that data to growers. By understanding crop load cooperating grower, Betts Farm LLC, was able to use variable rate controllers to follow a sensor based prescription map to increase uniformity in their crop load. It was easy to observe their brix accumulating much faster than the industry average. This was particularly impressive on blocks that experienced stress in 2016.
This is where the efficient vineyard team will hit the books. The conditions on Betts farm in 2017 gave us a number of opportunities to improve the technology and help adoption. On the economic side of things, we will be comparing yields and brix to control blocks. We will also be taking a look at pruning weights to get an estimate of how management strategies’ in 2017 may impact potential revenue in 2018. Finally, we continue to make the case that the largest benefit of a balanced crop load is consistently higher average production because of return crop potential. The 2017 harvest will give us most of the information we need to analyze the performance of this technology in 2016, when Betts Farm began variable rate thinning. One year ago, results were very promising and the impact on the 2017 potential crop was clear. We can now verify how that potential crop turned into actual crop and actual dollars.