Vineyard bird control without netting - is it possible
Do you net your vineyard? Is it worth the time, cost and inconvenience? Are there alternatives that can be used effectively? These are compelling questions. Most winegrowers use bird netting of some form, simply because they need to or because it has been their main means of bird control, for many years. But, with the cost of labour for netting installation increasing, many growers are looking for more sustainable and efficient alternatives to deter birds.
The advantages of bird netting
Effective in most situations: Quality bird nets installed correctly, can be an effective bird deterrent. They provide a physical barrier between the birds and the fruit, mostly preventing bird access and the resulting damage.
A guarantee (of a sort): Once bird netting is installed, it significantly lowers the risk of bird damage in the vineyard until later in the season when the nets are removed.
The disadvantages of bird netting in a vineyard
Cost: Aside from the cost of the bird nets themselves, the number of man hours required per hectare of vineyard, largely contributes to the high cost of bird netting. With labour costs increasing and in some areas a vast shortage of labour, netting an entire vineyard comes with a substantial cost to the grower.
On average, netting a vineyard costs approximately $1250.00 per hectare per year, this includes the cost of the netting over a 10 year life span (although some nets only last for 3 - 5 years) along with the cost of labour to install and remove the nets, each season.
Timing: Bird netting takes time to install and remove. Also, in some areas as vineyard labour is in high demand and short supply, growers have to book this weeks or even months in advance. Inconveniences, that restrict both movements in the vineyard and the ability to harvest at the optimum time.
Canopy restrictions: Bird netting restricts canopy access and management. It also reduces the ability for late spray applications and management of diseases.
Storage: Netting is bulky and takes up space in storage for most of the year, when not in use.
Sustainability: NZ vineyards are recognised world-wide as having practices that are both sustainable and environmentally friendly. But does bird netting contribute to this?
Recycling: Little, if any, bird netting can be effectively recycled once it is decommissioned by a vineyard, contributing to the environmental damage caused by waste plastics.
Not completely effective: Bird netting often does not provide complete protection for grapes. Especially as the netting ages and has tears and holes that allow bird access. Hungry birds will take advantage of the smallest of holes that allow access to the grapes. With over-row net, particularly those covering multiple rows, if birds find a point of access it can become (as one grower put it) a large bird aviary. Large flocks of birds can also perch on and weigh down, side net, giving them access to the fruit. Light colour netting particularly, makes it easy for birds to see the contrasting grapes behind, if they can find a way through, they'll find it!
Harvest time: Prior to harvest bird nets have to be removed, exposing the grapes at the time when they are the most attractive to the birds!
If bird netting isn't so great, are there alternatives and what are they? In the past, alternative methods for deterring birds without netting, have been limited, particularly in high bird pressure areas. Options from the simple scarecrow to gas gun bangers, whilst deterring birds to some degree, haven't necessarily had the effectiveness to allow them to replace netting completely. Bird deterrents have more been used as a supplement to netting, to help deter birds from the area in general. Other methods including shooting and use of quad bikes are costly, labour intensive and unsustainable. But now, technology is changing bird control. Advances in technology, as in many industries, is changing the way growers can solve their bird problems. Are there alternatives to netting and what are they? Read more in our article - technology is changing bird control.