Is it Worth Protecting Grapes with Bird Netting?
Why is bird control in grapes an issue?
Grapes with Bird Netting is another option to protect your vineyards from Birds. It have be estimate that birds eat approximately 10% of the grape harvest in British Columbia, Canada each year. The losses vary significantly from year to year and also between locations and varieties (red grapes are the most vulnerable).
Large flocks of birds are capable of consuming a large part of the crop, which represents thousands of dollars per acre in lost income.
Birds are more problematic in smaller vineyards and in those vineyards that are surround by trees.
Why bird barrier netting?
Visual and noise-making devices frighten birds and initially scare most birds away from the crop when used correctly; however, birds can become accustomed to these deterrents and the devices become less effective.
Neighbors living close by will not become accustomed to noise making devices, will find them annoying, and will not be happy about them.
Correctly installed bird barrier netting (also known as anti-bird netting or simply bird netting) provides much more protection because, instead of attempting to scare off the birds, it constitutes a physical barrier so that the grapes are inaccessible to birds.
With visual and acoustical devices there are degrees of protection. With bird netting, there is complete protection for the entire vineyard and netting does not bother the neighbors.
Making the best financial decision regarding netting
This informative guide will aid growers in evaluating the financial costs and benefits of using GUACAMALLAS® anti-bird netting for their vineyard using the single-row drape netting method, also known as the envelope system.
Other factors, such as the suitability of the nets for the operation of the farm in general and the impact of noise-making devices on relations with the neighbors.
Should be take into consideration when making a decision about covering up your grapes with bird barrier net.
Let the following steps guide you while filling out the worksheets at the end of this article with information for your specific farm.
The final step will show you if it is worthwhile installing anti-bird netting to protect your grapes.
Step #1
Capital costs
How much money will it take to install netting per acre (or hectare)?
This is the starting point for making a decision about single-row drape netting. This method does not use permanent supports; therefore, the only start-up investment costs are the plastic netting itself and the necessary accessories and/or equipment to spread it out.
It is possible to apply and then, immediately prior to harvest, retrieve the netting entirely by hand; however, to facilitate the task, speed up the process , and reduce labor, there are devices and equipment available ranging from simple to sophisticated and priced accordingly.
Remember, the netting will need to be wide enough to cover both sides of the row.
Suppliers such as HORTOMALLAS®® can help you calculate the exact amount of netting needed.
Divide the cost of equipment for applying and retrieving the netting by the number of acres or hectares of your vineyard to obtain the the equipment cost per acre or hectare.

Step #2
Annual depreciation and interest costs
What is the annual cost of the investment?
These are the costs to be considered when calculating the annual cost of investment.
In this step take the cost of buying the netting and equipment and spread it out over its expected useful life.
The annual depreciation amount is an estimation of the annual loss in value of the netting and equipment as it wears out. The simplest way of estimating this cost is to divide the value of the installed netting by the number of years of expected useful life.
Do the same for the equipment. For the worksheet these costs need to be per acre or per hectare.
The cost of interest is the interest pay on the money borrow for the nets or the interest income that can be realize from a different investment (for example another project, bonds, or money market certificate).
Annual interest costs vary, but an arbitrary rate of 6%, for the sake of illustration, is use as an example in the worksheet for Steps #1 and #2.
For your information (last column), use the interest rate for your loan, if you borrowed money, or the rate of return for an appropriate investment.
Interest is usually calculate using the average value of the investment during its useful life. In other words, at the midpoint between the beginning value when new and the value when completely depreciated.
Step #3
Annual costs
What will the annual cost be of using the netting?
These are the costs for spreading out and then, immediately prior to harvest, retrieving the bird netting each year and for any repair and maintenance. The example column in the worksheet assumes 2 hours per acre for spreading out and 4 hours per acre for retrieving the netting.
For your information, use the appropriate number of hours for the equipment (if any) that you will be using and the hourly rate for labor for your farm.
Calculate maintenance costs by using a percentage of the investment cost. Generally, 3% is use for investments such as anti-bird netting. Unexpected costs always come up. Plan for these costs with a contingency fund of 5%.
Step #4
Risk
How much more is need for uncertainty about the future?
There is nothing for sure about agriculture. Prices and yields of grapes change, annual markets shift, and growing conditions vary. In addition there can be unforeseen damage to the netting.
But payments must still be made. Keep these risks in mind and make sure that payments can still be made even in the case of a setback.
Budget for risk as a percentage of expected costs. This can be as low as 5% for a low-risk investment or as high as 50% for a high-risk investment and a large debt.
Step #5
Total annual cost of the netting
What is the total annual cost for the bird barrier netting?
Add up the costs from Steps #2, 3, and 4 to get the total cost.
Remember to consider cash flow. If you take out a loan for nets, be sure to see how loan payments will affect your operation. Be sure you have enough funds and a line of credit available so that you do not find yourself in a cash flow crunch.
If the project yields a long-term net benefit, financing the project with your own resources, will eliminate any obligation for making loan payments.
Step #6
Added annual returns
Will there be more income from the bird netting?
Consider the value of the extra grapes harvested from a crop protected by netting and the additional costs for harvesting and selling the grapes. Study the following two tables.
Table 1 shows the grapes saved by one acre of anti-bird netting. The first column shows different yields per acre, without any bird damage by using netting, and the other columns show the amount that would have been lost per acre at different percentages of bird damage, without netting.
This is the amount saved by using bird barrier netting. You need to estimate your average annual level of bird damage.
Table 2 gives the additional gross annual yields, by using netting, for different amounts of grapes saved at different prices. Prices for grapes vary, but, as an example, a price range is used from $900 to $1,400 CAD per ton.
Cash Flow Problems?
- If you will provide the labor yourself, omit a part of the labor cost when calculating the annual cost for nets (see the second worksheet).
- If you are currently using other devices to protect your grape crop, subtract this cost from from the annual cost for nets. This could be as much as $200 CAD/acre/year.

Table 2. Break-even Point and Annual Added Gross Return with Netting ($/acre)

Step #7
Break-even point
Will the netting pay for itself?
The break-even point is the point where the added annual cost of the nets is as much as the added annual gross return of the nets. Nets are worth the investment if the added returns are greater than the annual cost of the nets.

In the example being used, it is worthwhile using anti-bird netting if the added annual gross return is in the unshaded area of Table 2. The added netting cost per acre in Table #2 comes from the example in column 6 of the last worksheet.
Will anti-bird netting pay for itself on your farm?
After working all the way through all of the worksheets, filling in your information, you will have your answer in the final column (#8) of the last worksheet.
W o r k s h e e t s
Steps #1 and #2. Capital Costs, Annual Depreciation, and Interest Costs
Steps #3, #4, and #5. Total Annual Cost of the Netting
Step #6. Added Annual Return
* The costs of the nets were relevant for British Columbia, Canada in 2002 and were based on a block of 10 acres using the envelope system (single-row draping). For smaller areas, irregularly shaped areas, and broken terrain the cost would be more.
** Equipment costs are estimated to be $1,200 CAD or $120/acre for a 10 acre vineyard
*** 20% loss on 4.0 tons/acre yield. Based on Table #1.
Leave a comment
Why is bird control in grapes an issue?
Grapes with Bird Netting is another option to protect your vineyards from Birds. It have be estimate that birds eat approximately 10% of the grape harvest in British Columbia, Canada each year. The losses vary significantly from year to year and also between locations and varieties (red grapes are the most vulnerable).
Large flocks of birds are capable of consuming a large part of the crop, which represents thousands of dollars per acre in lost income.
Birds are more problematic in smaller vineyards and in those vineyards that are surround by trees.
Why bird barrier netting?
Visual and noise-making devices frighten birds and initially scare most birds away from the crop when used correctly; however, birds can become accustomed to these deterrents and the devices become less effective.
Neighbors living close by will not become accustomed to noise making devices, will find them annoying, and will not be happy about them.
Correctly installed bird barrier netting (also known as anti-bird netting or simply bird netting) provides much more protection because, instead of attempting to scare off the birds, it constitutes a physical barrier so that the grapes are inaccessible to birds.
With visual and acoustical devices there are degrees of protection. With bird netting, there is complete protection for the entire vineyard and netting does not bother the neighbors.
Making the best financial decision regarding netting
This informative guide will aid growers in evaluating the financial costs and benefits of using GUACAMALLAS® anti-bird netting for their vineyard using the single-row drape netting method, also known as the envelope system.
Other factors, such as the suitability of the nets for the operation of the farm in general and the impact of noise-making devices on relations with the neighbors.
Should be take into consideration when making a decision about covering up your grapes with bird barrier net.
Let the following steps guide you while filling out the worksheets at the end of this article with information for your specific farm.
The final step will show you if it is worthwhile installing anti-bird netting to protect your grapes.
Step #1
Capital costs
How much money will it take to install netting per acre (or hectare)?
This is the starting point for making a decision about single-row drape netting. This method does not use permanent supports; therefore, the only start-up investment costs are the plastic netting itself and the necessary accessories and/or equipment to spread it out.
It is possible to apply and then, immediately prior to harvest, retrieve the netting entirely by hand; however, to facilitate the task, speed up the process , and reduce labor, there are devices and equipment available ranging from simple to sophisticated and priced accordingly.
Remember, the netting will need to be wide enough to cover both sides of the row.
Suppliers such as HORTOMALLAS®® can help you calculate the exact amount of netting needed.
Divide the cost of equipment for applying and retrieving the netting by the number of acres or hectares of your vineyard to obtain the the equipment cost per acre or hectare.

Step #2
Annual depreciation and interest costs
What is the annual cost of the investment?
These are the costs to be considered when calculating the annual cost of investment.
In this step take the cost of buying the netting and equipment and spread it out over its expected useful life.
The annual depreciation amount is an estimation of the annual loss in value of the netting and equipment as it wears out. The simplest way of estimating this cost is to divide the value of the installed netting by the number of years of expected useful life.
Do the same for the equipment. For the worksheet these costs need to be per acre or per hectare.
The cost of interest is the interest pay on the money borrow for the nets or the interest income that can be realize from a different investment (for example another project, bonds, or money market certificate).
Annual interest costs vary, but an arbitrary rate of 6%, for the sake of illustration, is use as an example in the worksheet for Steps #1 and #2.
For your information (last column), use the interest rate for your loan, if you borrowed money, or the rate of return for an appropriate investment.
Interest is usually calculate using the average value of the investment during its useful life. In other words, at the midpoint between the beginning value when new and the value when completely depreciated.
Step #3
Annual costs
What will the annual cost be of using the netting?
These are the costs for spreading out and then, immediately prior to harvest, retrieving the bird netting each year and for any repair and maintenance. The example column in the worksheet assumes 2 hours per acre for spreading out and 4 hours per acre for retrieving the netting.
For your information, use the appropriate number of hours for the equipment (if any) that you will be using and the hourly rate for labor for your farm.
Calculate maintenance costs by using a percentage of the investment cost. Generally, 3% is use for investments such as anti-bird netting. Unexpected costs always come up. Plan for these costs with a contingency fund of 5%.
Step #4
Risk
How much more is need for uncertainty about the future?
There is nothing for sure about agriculture. Prices and yields of grapes change, annual markets shift, and growing conditions vary. In addition there can be unforeseen damage to the netting.
But payments must still be made. Keep these risks in mind and make sure that payments can still be made even in the case of a setback.
Budget for risk as a percentage of expected costs. This can be as low as 5% for a low-risk investment or as high as 50% for a high-risk investment and a large debt.
Step #5
Total annual cost of the netting
What is the total annual cost for the bird barrier netting?
Add up the costs from Steps #2, 3, and 4 to get the total cost.
Remember to consider cash flow. If you take out a loan for nets, be sure to see how loan payments will affect your operation. Be sure you have enough funds and a line of credit available so that you do not find yourself in a cash flow crunch.
If the project yields a long-term net benefit, financing the project with your own resources, will eliminate any obligation for making loan payments.
Step #6
Added annual returns
Will there be more income from the bird netting?
Consider the value of the extra grapes harvested from a crop protected by netting and the additional costs for harvesting and selling the grapes. Study the following two tables.
Table 1 shows the grapes saved by one acre of anti-bird netting. The first column shows different yields per acre, without any bird damage by using netting, and the other columns show the amount that would have been lost per acre at different percentages of bird damage, without netting.
This is the amount saved by using bird barrier netting. You need to estimate your average annual level of bird damage.
Table 2 gives the additional gross annual yields, by using netting, for different amounts of grapes saved at different prices. Prices for grapes vary, but, as an example, a price range is used from $900 to $1,400 CAD per ton.
Cash Flow Problems?
- If you will provide the labor yourself, omit a part of the labor cost when calculating the annual cost for nets (see the second worksheet).
- If you are currently using other devices to protect your grape crop, subtract this cost from from the annual cost for nets. This could be as much as $200 CAD/acre/year.

Table 2. Break-even Point and Annual Added Gross Return with Netting ($/acre)

Step #7
Break-even point
Will the netting pay for itself?
The break-even point is the point where the added annual cost of the nets is as much as the added annual gross return of the nets. Nets are worth the investment if the added returns are greater than the annual cost of the nets.

In the example being used, it is worthwhile using anti-bird netting if the added annual gross return is in the unshaded area of Table 2. The added netting cost per acre in Table #2 comes from the example in column 6 of the last worksheet.
Will anti-bird netting pay for itself on your farm?
After working all the way through all of the worksheets, filling in your information, you will have your answer in the final column (#8) of the last worksheet.
W o r k s h e e t s
Steps #1 and #2. Capital Costs, Annual Depreciation, and Interest Costs
Steps #3, #4, and #5. Total Annual Cost of the Netting
Step #6. Added Annual Return
* The costs of the nets were relevant for British Columbia, Canada in 2002 and were based on a block of 10 acres using the envelope system (single-row draping). For smaller areas, irregularly shaped areas, and broken terrain the cost would be more.
** Equipment costs are estimated to be $1,200 CAD or $120/acre for a 10 acre vineyard
*** 20% loss on 4.0 tons/acre yield. Based on Table #1.
Leave a comment