|Seyve Villard 5-276 "Seyval"|
This page describes a method of bird net application which--
* eliminates the need for removal of the
netting before harvest
* permits the pickers to access the fruit
as they progress
* extends the life of your netting
about 10 fold
* reduces the amount of netting you
will need by 33% to 50%.
Two other images may be seen by clicking on the Seyval image. A return button is available.
1. Bird net installed over the row at about 9-10 brix (the point of ripening when birds start to take an interest) will have a lot (too many) shoots growing through it when its time to take it off. If you don't carefully cut the shoots before you uninstall, you will end up with perilous rips in the net.
2. Bird net attached to mother earth is an automatic invitation for birds and other creatures to find their way underneath the edge of the netting. Unfortunately, not all industrious creatures find the gaps. After the birds scoot under the net, snakes hear/sense the birds struggling inside the enclosure. Snakes interweave themselves in the net until they can't go forward or backward. Cutting the net to remove a live snake, or cutting a dead snake that has been in the sun for a couple of days are equally objectionable tasks.
3. Grass, especially crab grass will grip earth anchored bird net and render whatever residue of the net you have left on the ground a tattered mess when you pull it up.
In order to avoid all of these annoyances, don't install your bird net over the row and don't anchor it to the ground. Cover the fruit zone only, below the canopy and well clear of the ground. Visualize your bird net as a shower curtain. It is suspended from a rod and closed at the bottom.
To accomplish this task, you will have to create bird net curtains that slightly exceed the distance between your line posts (in our case 26 foot lengths). The width of these curtains will be one third of the width of 14' netting (56") or one quarter of 17' (51"). This is how you achieve the 50% to 100% bonus in the amount of netting available for fruit protection and a 33% to 50% reduction in the amount you will have to purchase. Each of these small curtains may be easily installed/uninstalled by one person.
You will need the 12 Wire Trellis (see page posted in Vineyard Planning and Renovation) or something similar. You will also need three installation fixtures; a spreader stick, wire anchor pins, and a loop of twine with a hook on the end.
You will need the 12 wire trellis described in the Vineyard Planning and Renovation section or some variation thereof. The top and bottom, narrow aperture curtain wires and the spreader stick wires are essential to this netting method.
Your goal is to arrange the fruiting zone in a 3 to 3.5 foot area to accommodate net curtains of 51" to 56" which cover the angle between the top and bottom curtain wires and the tip of the spreader stick. Keep in mind, however, that the fruit zone should begin about 40" above grade to facilitate easy picking. So the spreader stick wires stick should be about 56"above grade.
The trunks pass through the bottom double curtain wires. If the 1.5" aperture seems small, remember that these are non-weight bearing wires and are flexible. Your objective will be to keep them as close as possible. When the bird net is installed, the anchor pin at each vine (one on each side of the row), may be removed from the wire and woven through the two skirts of netting below the wire on each side of a large trunk, thus closing the area around the trunk and the space between the vine and its neighbor.
All annual growth passes through the 1.5" aperture in the top curtain wires. This may be accomplished with management activity that is not burdensome. Remember, all annual growth has already passed through the wider area between the spreader stick wires, so the vines have been partially trained and are easily tucked between the curtain wires. Certain varieties of grapes with rambling growth habits will require more work, but the varieties with vertical growth habits are a piece of cake.
At the same time you are tucking, you may pull off emerging laterals, or "suckers" in the elbow between leaf stem and shoot. This action will reduce the amount of growth which must pass through the top curtain wires to a manageable level. Your objective is to fill the top aperture with annual growth to shut out the birds, but not permit excessive and unnecessary growth in the fruit zone area. If some growth is outside the curtain wires at veraison, fasten it to the wire and install the netting around it. Late season growth (e.g. laterals that you overlooked, will be growing through the net at picking time, but these should be about one per 50 feet of row. Where the gap between the top curtain wires remains empty and open because of a missing vine, the gap may be easily closed after you install the net curtains by weaving the pins through both curtains as described above for trunks.
Spreader sticks, as crudely illustrated on the graphics page, are a 24-28 inch piece of 3/4" X 3/4" furring strip with a shorter piece of the same stock suspended on a light bolt underneath to serve as a clamp when inserted over the two permanent catch wires in the center of the fruit zone. Tennis balls on the end of the stick are ideal for keeping the stick from threading the net. The Sticks are necessary because, without them, the net would be in such close proximity to the fruit that a bird could grasp the net and have a feast. The sticks should be installed about every eight feet in the row.
Anchor pins are U shaped pieces of wire six to nine inches in length which are woven through the net curtain, behind the net wire, and back through the net at both the top and the bottom of the curtain. We use one pin for each vine on both sides of the row. A six inch box staple is available commercially, and works fairly well, but be sure to buy them galvanized. On the down side, the box staple has a squared top which tends to get its shoulder into the net and is extracted with difficulty. A true U shape at the top avoids this problem.
The twine (or piece of monofilament) with hook is the item that is going to enable your pickers to open the net themselves without removing it during the harvest. When approaching a closed section of net, the picker pulls the anchor pins from the bottom of the net curtain. At each spreader stick, the picker finds a twine loop attached to the top curtain wire. The picker grabs the bottom of the curtain with one hand, raises it, brings the hooked end of the twine out and around the curtain bottom and hooks the top curtain wire. Three spreader sticks, three hooks and a 24 foot section of row is opened wearing a roll of netting resembling a raised venetian blind. Depending on your picker, from pulling the first pin to opening the section takes 1.5 to 2 minutes. If there is a picker on the other side of the row, he/she may work independently
Hooks for the twine loops? Without them, opening the net will take much more time. Ours are homemade from aluminum wire. What's on the market? Drapery hooks? Fish hooks with tip cut off. Any other ideas?
Tennis balls. You'll be surprised how many you get just by putting the word out to your tennis player friends. Better idea? Let us hear it.
After harvest, the net curtains should be removed from the vineyard as soon a possible. Store in a cool dark place. Good outdoor storage is provided by open head plastic drums stored in the shade.
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