Hail Protection Netting in Vineyards.

Hail protection netting costs and insurance savings

Anti-hail netting in vineyards is a specialized protection system and an indispensable tool for safeguarding production.

A crop protected by hail netting assures consistency in marketable products, both in quality and in quantity. Besides the possibility of planning the work, producing more homogeneous fruit maintains constant costs and prices. Hail protection netting should be included as a part of production costs. Generally speaking, a hail netting structure gets amortized over 20 years at a 5% rate. It is also necessary to take into account the annual management costs of the hail netting, of beginning and ending the season.  The costs of a hail protection system are of low volatility from year to year.

However, anti-hail netting makes insurance cost savings possible and often can turn out to be beneficial when the difference between the two alternative expenditure items is calculated.

In zones of intense hail, hail netting becomes a forced choice. Hail netting in vineyards, known as a proactive defense, has as its objective safeguarding the crop. Also, it has the advantage of being a fixed cost during the life of the structure, whereas insurance costs vary from year to year.

There are three methods for dealing with the threat of hail damage:  hail canons, cloud seeding, and netting.

There is not very much sound science behind hail canons or evidence that they work (the loud boom supposedly disrupts the hail-forming process in the cloud), but there is good science behind cloud seeding. 

Choosing to install hail protection netting, results in being more beneficial for safeguarding the crop and has the additional advantage of being a constant figure for cost and not changing over time.

A crop protected by anti-hail netting assures consistency in marketable product, both in quality and in quantity.
A crop protected by anti-hail netting assures consistency in marketable product, both in quality and in quality.

A support structure for anti-hail netting in vineyards

The netting can easily be hung on structures or placed directly on crops. For cash flow projections for a hail netting structure, a minimalist support structure should be considered. The structure becomes more important in the case of high-density installations. 

When a support structure is required, posts and anchors are a part of it. The basic elements of a support structure for hail netting include:

  • Anchors
  • Poles/posts
  • Cables and ropes
  • Shields for the poles

ANCHORS should be placed all around the perimeter and should be capable of guaranteeing the stability of the structure. In addition to being able to withstand the forces of strong winds, they also need to be able to withstand the forces of the weight of hail on the netting.

For this reason, the correct positioning of the buried straps is a distance of at least 2.5 – 3 meters (~ 9 feet) from the post being braced. 

It is not necessary to put in the posts slightly slanted inwards toward the row, but doing it this way allows some space to be recovered alongside the posts away from the row. 

POSTS. The type of post best suited for supporting hail protection netting is a concrete post. It is recommended that it be planted at a depth of 80 centimeters ( ~30 inches). Since this type of structure does not discharge the hail onto the ground and needs to be capable of bearing its weight, it is critical that post spacing in the row is more than 8 meters (~26 feet).

CABLES AND ROPES are used to shore up the anti-hail netting lengthwise and crosswise against a possible hail storm. It is recommended that cables are sheathed in plastic to avoid direct contact with the netting, which might cause tears and damage the fabric. This is a key aspect in assuring the longevity of the netting.

Anti-Hail Netting
A crop protected by anti-hail netting assures consistency in marketable product, both in quality and in quantity.

SHIELDS FOR THE POLES. A post shield not only serves for protecting and preserving the net but also for securely fastening the top part of the post to the crosswise cables. 

Hail netting in vineyards

The GRANITA® hail protection netting has great durability of being able to sustain 500 kilos (~1,100 pounds) per meter.

When there is a chance of snow, the netting should be rolled up onto the tops of the posts and left in a roll. Once there is no chance of snow, it gets unrolled again. This is an annual chore but is indispensable for the protection of the structure of the crop. 

Black hail netting is the most used color because it has a useful expectancy of 15 years. 

MOUNTING PLATES. The accessories for an anti-hail netting system consist of mounting plates that get used for fastening the netting. They need to be sturdy and able to be installed quickly.