The purpose of this project is to reduce bud damage in vineyards by providing a targeted heat source to the fruiting buds during extremely cold weather. The vines will be pruned and tied to the heat tape and covered with tube insulation. A thermometer probe inside the tubing will ensure that the heat tape maintains an internal temperature of 0 degrees F. In the spring, the insulation will be removed and the vine will resume its normal growing conditions.
The ability to guarantee a crop of fruit despite variable cold temperatures is of paramount importance for fruit growers situated in the northeast, and this has become more challenging in recent years. Climate change has modified the pattern of the polar vortex, causing both extreme colds and significant variability in temperatures. These factors have caused significant winter damage to the fruit buds over the past 3 years, causing yield losses, and financial losses for fruit growers. Additionally, in some cases, extreme temperature variability has caused fruit buds to deaclimate earlier in the dormant season, making the fruit buds vulnerable, and creating the opportunity for any cold temperatures to destroy the bud tissue.
We would like to explore a sustainable, automated solution to protect the fruit buds that involves using a combination of electrical heat wire and insulation along the fruit-zone of the vine to create a precisely targeted area of warmth to directly where the buds are located. While fruit growers have attempted to manage risk from extreme colds in several ways, each of these methods has specific weaknesses. We believe that it is imperative to find a more sustainable, automated solution that will effectively protect the fruit.
Our proposal is to install electrical heat wire and insulation along the fruit zone of the vine to create a targeted zone of heat. The temperature inside the insulation will be monitored with a digital thermostat, and the system will be activated and provide heat when the temperature drops below a threshold. The insulation will be used to contain the warmth within the fruit-zone. Additionally, in the spring, when the insulation is removed for the growing season, the heat wire alone may be sufficient enough to provide protection from an early frost. While our pilot is targeted to grape vines, we envision that this system could also be used for other trellised fruit, including apples, pears, and stone fruit.
Our objective is to use the system described above to automatically warm the fruiting zone when temperatures are below a threshold to ensure that the primary buds survive and provide a full yield of fruit, as compared to a control.
Installation of equipment (12/1/17 through 12/14/17):
- Cane Prune Vines (normal vineyard process)
- Install Heat Cable on Fruiting Wire. Unroll heat cable and attach to fruiting wire using the cable ties. Attach thermostat to the heat cable using 14 gauge extension cord. Connect thermostat to an appropriate power outlet (240v) and adjust settings for operation at 0 degrees F.
- Heat Cable: Briskheat Self-Regulating Heating Cable SLCAB10240BP
- Thermostat for Heat Cable: TC4X-2 Digital On/Off Thermostat
- Cable Ties to attach heat cable to fruiting wire
- Extension cord (cut to desired connection length)
- Tie Canes to Fruiting Wire (normal vineyard activity)
- Install Insulation. Make a small incision in insulation tube and wrap it around the fruiting cane/heat cable/fruit wire for the length of the row.
- Armaflex COIL 5/8″ ID x 1/2″ Wall
- Install Data Loggers. Attach data loggers on end posts to measure and log temperature differences throughout the season.
- HOBO MX2303 – Dual Probe (Air vs Inside Insulation)
- HOBO MX2304 – Single Probe (used to measure temperature inside insulation at end of row to validate full length of heat run)
At this point, the current temperatures have not hit our trigger point of below 0 degrees F. Thus, we do not have results that would satisfy this requirement.
I did find significant cost savings on the material by sourcing directly from the manufacturer.
As pointed out above, we are still awaiting temperatures to drop below our targeted value of 0 degrees F.
Education & Outreach Activities and Participation Summary
Because this is project was not implemented until December of 2017, the observations and results will most likely be available in the Spring of 2018.
Thus far, there are no results of the project because we are awaiting bud break on the vines in the Spring of 2018.
There is nothing to report at this time because the project is awaiting colder temperatures and bud counts thereafter.
At this point in time, one of the more challenging aspects of this project is waiting for the weather to produce conditions that would lead to bud damage. It appears as though we may have some conditions this season that would result in some minimal bud loss, but we will not know until the spring. I look forward to providing more thorough results hopefully in the summer of 2018.