Cold climate grapes: Determining an appropriate training system for improved yield

Cold climate grapes: Determining an appropriate training system for improved yield

Summary

The purpose of my project has been to study the feasibility of increasing yield and quality of cold climate hybrid wine grapes through matching training systems with the vigor type of the varieties grown. This utilizes hybrid wine grape varieties well suited to the Northeast. My goal is to collect useful data to be shared with others through in field meetings, flyers and posting to an online forum and my vineyard website www.hipvineyard.com .

There are four training systems implemented for each of four grape varieties with three replications of each. There are two single fruiting wire systems (either cane or cordon pruned) and two split systems with two fruiting wires. By demonstrating these, other area vineyards have been and will be exposed to the differing systems they might not otherwise be familiar with, especially the Scott-Henry and the Modified Geneva Double Curtain of my own design. They have be able to visualize the planning and training processes that went into the systems used in the trial project. The four training systems are: Top Wire (High Wire) Cordon – TWC, Vertical Shoot Positioned (Mid Wire Cordon) – VSP, Modified Geneva Double Curtain – MGDC and Scott-Henry.  

The project year began with an in field pruning demonstration meeting attended by 17 individual growers and interested parties. I covered the basics of the trial vineyard layout and pruning basics for each of the training systems. Another field demonstration was held in August to show how the vines had progressed through the summer which was attended mainly by Extension personnel from the northeast US and Canada and a few indiviual growers. A final meeting was held post harvest to recap the season and had the best attendance with a great mix of growers and Extension personnel.

Objectives/Performance Targets

It was determined that our target number of 5 buds per foot of canopy would be used so all vines were dormant pruned to that number when  possible. As a result of heavy production in 2013 and a late harvest that year many of the shoots did not harden off well on the two red varieties, Marquette and Mn1200. As a result they were pruned back to a viable bud and in many cases that meant to the cordon. Because of that the bud count was low and later affected the yield quite a bit.  A decision was made to not make a bud count post pruning since we could not tell at that point which buds would add to the crop. During the growing season all the vines were monitored for proper growth and development during the growing season by myself and my assistant Richard Lamoy, Jr.. Each repetition was trained to its appropriate training system but otherwise were handled the same way. Leaf pulling was be done by me and my field assistant to open the canopy up and help reduce fungal pressure and needed sprays, thus having less environmental impact. 

The time needed to implement the different training systems was roughly logged for the various operations needed for the particular system. The ripeness was monitored by a combination of brix (to measure soluble solids), pH, and TA (total acidity). Samples of 50 grape berries were collected from each repetition of each variety (12 rows x 4 varieties= 48 samples) every week to 10 days beginning September 1 through picking in late September and early October. This provided 4 sample collection periods. The 50 grape samples were collected in zip lock type bags, crushed and used for samples. Prior to crushing, the samples were weighed to provide average grape berry weight. 

Maximizing return and quality demands that results of any testing be available quickly so on-farm testing was used. Electronic testers were used for measuring the pH and TA (acids) at the vineyard. Brix (soluble solids/sugars) were measured with a refractometer. The testing on the samples was performed by Richard Lamoy, Sr.. When optimal ripeness and quality were reached, the grapes were harvested by variety and all grapes weighed and recorded on a per vine basis along with a cluster count. This weight and cluster count information is useful in determining the number of retained buds at subsequent dormant pruning. This process is also very useful in putting values to the yields and quality obtained for comparative and analytical purposes. 

By measuring and recording results for each variety trained to the four different systems, the best training system or systems can be determined for each grape type. This assumes that there will be a “best method or system” for each type, such as low vigor white wine grape. This may or may not be the case and is what this training system trial has been trying to determine.

Accomplishments/Milestones

The results of the trial have been mixed this year. The winter of 2013-2014 was very cold and open at the trial vineyard with lows greater than -20F several times. That on top of very high yield and late harvest in 2013 led to a lot of shoot dieback and death on both the Marquette and Mn 1200 vines.  As previously stated that lead to low bud counts on those two varieties and held back yield on those varieties. 

Both the St. Pepin and Petite Amie had hardened off well in 2013 so the canopy on those varieties was full and they yielded as would normally be expected. This complicates trying to analyze the results for the trial this year. It also shows that there are other factors that come into play when making a decision on which training system to use.  I will get into much greater detail as I continue analyzing the data as I prepare the final report.

Impacts and Contributions/Outcomes

Collaborators: