Ministry of Agriculture & Lands
Tree Fruit and Grape Industry News, July 1999
Using Propane Cannons
Propane cannons are a popular tool used to scare birds and protect crops including grapes, cherries and apples. Guidelines have been provided under the Farm Practices Protection Right to Farm Act (FPPA) in the Wildlife Damage Control Farm Practice. The basic guidelines include:
- Using noise devices only when required for the protection of specific crops and only when a problem is evident.
- Operating noise devices only between 6:00 a.m. and 8:00 p.m. local time.
- Using no more than one noise device per two hectares of crop land at any one time.
- Where possible, aiming directional sound-producing devices away from neighbours.
- Maintaining propane exploders properly to avoid continuing noise when exploders are shut off.
- Locating noise devices as far away from neighbours as
possible. - Erecting a noise barrier if feasible.
Of the various noise-making devices used for crop protection, propane cannons cause the most complaints by neighbours. Some of the more common complaints are:
- Cannons operating during "off" hours of 8 p.m. to 6 a.m.
- Cannons located too close to a neighbouring residence.
- Cannon noise too frequent.
Cannons going off at night is due to equipment malfunction or operator error. Batteries used to operate the cannon timer clock should be replaced as the battery power becomes low. The clock may also require periodic calibration to ensure it is keeping proper time. If the owner lives within hearing range of the cannon, then when the cannon is operating outside of the allowable time frame, the cannons should be fixed or turned off until the timer can be fixed. In those situations where the owner plans to be away from the property where the cannon is operating, arrangements should be made with a local person who can turn the cannon off if it malfunctions. Alternatively or in addition, communicate with neighbours to inform them of who should be telephoned to turn the cannon off. Provide a telephone number that will not ring busy due to heavy use. Eliminating or reducing this problem is probably the easiest complaint to deal with while maintaining cannon effectiveness.
Cannons that are located close to neighbouring residences are loud. Although the FPPA guidelines do not contain specific reference to a distance, the Environmental Guidelines for Tree Fruit and Grape Producers suggest not using a rotating cannon within 100 m of a neighbouring residence. Directing the cannon away from the neighbouring residence and using noise buffers (such as hay or straw bales) are suggested measures to be used if the cannon is located within 100 m of an occupied dwelling. Specific recommendations for a noise barrier are not available at this point. Buffers may have to be fairly thick and dense to be effective. In some cases it may be possible to locate cannons such that an uninhabited building (such as a barn) is between the neighbouring residence and the cannon. The barn may act as an effective noise barrier.
The frequency of cannon explosions is another complaint. Most cannons have an operator adjustment that controls the explosions per hour. Operators should generally start the cannons off at a low frequency early in the harvest season and increase the frequency as the harvest season progresses. Start the cannons when birds first start to feed on the ripening fruit. If the birds become used to eating the fruit, then it is much more difficult to scare them away. Starting later will require more noise and will likely be less effective.
In some circumstances of lower feeding during the middle part of the day, it may be possible to have the cannons shut off with the timer clock. This will not only reduce the noise but may delay the birds from growing accustomed to the noise. Time the harvest so that the cannons could be off for the weekend, during or following the harvest. Of course, grapes and tree fruit crops must be picked when they are ready and the timing of the harvest is more complicated during mid season when multiple varieties are harvested.
The propane cannon is designed to produce a loud noise to surprise, startle and scare the birds away. The double and triple shot cannons are more effective than single shot cannons in scaring birds away.The two or three shots are caused by the same "trigger" and are spaced by the time it takes the cannon barrel to fill with propane and be ignited.
Cannons have also been elevated on tripods so that they are above the plant canopy and therefore protect a larger area. The cannons are mounted on swivels in such a way that the explosive force rotates the cannon between explosions. By changing the direction the cannons fire in, the random effect is enhanced without having to move the cannon from location to location as often.
Some growers have found that letting their neighbours know about their farming operation and why they follow certain practices increases their neighbours' understanding of why cannons are used. Neighbours who understand the issues are more likely to be accepting of crop protection practices. Farmers who take the time to communicate with their neighbours are more likely to be able to deal with concerns before they grow to the point where they are difficult to resolve.
Cannons should be used wisely, integrated with several other bird scaring techniques, moved every two to three days, and use a low frequency early in the season increasing with increasing bird pressure.
Bert van Dalfsen, PEng,
Mechanization Engineer, BCMAFF, Abbotsford
