Nets are to stop birds eating the grapes. It depends on your area and year.
Silver eyes do the most damage. The Silver eye is a fairly small bird of around 12 cm. This Native Australian bird is predominately an olive green colour the underparts of this Australian bird are a yellow-green. The Silver eye is quite indicative of its name; this is due to a silver coloured ring that surrounds the eye of this little bird.
Apparently the French love to eat small birds? They hang them upside down in their chimneys and eat them off the bone. As a pest to us I could see a great export opportunity!
For us we don't net because we have heaps of flowering blossom on the gum trees which is their main food source. They have red or white flowers and surround our property as part of the road verge vegetation. Who would have thought that would be so valuable.
But is some years the blossom is knocked off or the trees don’t blossom as well and this can cause problems. In 2005 we had a tail end of a cyclone come through and drop 7 inches of rain in one day. This knocked the entire blossom off and after a few rainy days the birds were starving! Then it was a race against the birds. We got the harvester in to harvest the fruit which was in good condition. However the harvester got bogged because the ground was so wet and couldn’t continue.
I was like ‘Now what?’
The harvester contractor said we better start hand picking. We had to handpick all our reds which are two thirds of the vineyard. We started at 6am and picked til 6pm and then crush whatever we had til midnight, find a few hours’ sleep before we started again. We did this for 4 days straight and we left two blocks of Shiraz which was damage too much by the birds. It wasn’t my most enjoyable vintage!
Now our biggest pest at the moment is Kangaroos. With increased blue gum plantations around us they have increased in number. They love our tasty grapes and do quite a bit of damage. Every night we would have 10+ roos in the vineyard all 100kg + each. We are now improving and perimeter fence and making it a little higher to deter the roos. But they can still enter via the front gate!