Large garden plots and multi-acre agricultural growers require effective bird control coverage to deter flocking birds.
The best pest bird control product for gardens or large agriculture areas is a audio bird deterrent system that incorporates a variety of species specific alarm / distress sounds in a random pattern so the birds cannot become accustomed to the same sound / same speaker syndrome. The Bird Wailer and Bird Squawker are excellent examples of this type of bird deterrent system. Both are extremely effective at modifying bird behavior from large and small areas.
All bird scare products work best when used in combination with each other as they increase the birds fear and flight response to the perceived predator threat.
Blog - Solving bird problems at Blueberry farms: http://solvingbirdproblems.blogspot.com/2015/07/stop-damage-to-blueberry-crops-using.html