Nets & Sprays

[meridaen]

So this is the first year that my vines are going to be giving me something to work with come February. We don’t have a lot of things that ruin your crop down here, but we do have powdery mildew and we do have birds. Lots of them.

The nets will have to come out from Christmas onwards, but I have a couple of basic questions as I haven’t done all this before on my own, and I’m a bit confused about a few things.

1. Do nets increase your susceptibility to PM, given the cuts down on air circulation? I realise that the berries are mostly immune to it after verasion, but I imagine it could still be an issue.

2. Which leads me onto this one, how do you spray if you have the nets on? Surely you can’t just leave the canopy for a month or I would imagine you’re setting yourself up for another big fight the following growing season.

I live near Heathcote (Victoria) and things are pretty dry and hot most years, but word is we’ll have our fourth wet summer in a row, so it’ll be another long fight. Just a couple of things that have been on my mind even though it’s bearly budburst here.

 

[David Engel]

Unless your birds eat green grapes or grapes that are still hard and haven't started to turn, nets are necessary at THAT time when the birds just seem to know the snacks are ready. I just lost 90% of my Pinot Noir because I didn't put nets up soon enough. Can't comment on spray, we don't spray (too small a vineyard).

 

[richinsd]

1. nets go up when the grapes start to get sweet. nothing seems to bother them before they are sweet. verasion is our trigger for the reds. with whites you should test ours are usually sweet before the reds hit version.

2. you can absolutely spray through nets. depending on weather I end up spraying 2-4 times with nets on. we have bee netting (vs. bird netting). as long as you thin leaves/canopy to allow circulation around the fruit you should be fine. the nets will cause the shoots to bunch up in some places and you'll lose some leaves because of it....but the part of the shoot above the net is usually fine. do not go a month without spraying.

 

[meridaen]

Is that with VSP though @richinsd ? I just have a sprawl as the sun is ridiculous down here, so I’ll be throwing a net over the whole show. Good to know that I can spray with the nets on. I live on the edge of a protected wetlands so the birds are plentiful and moving on sans netting will result in zero grapes.

 

[Snafflebit]

You have an interesting problem. I also net over a sprawling canopy, but I stop spraying after I net. My nets are rarely on longer than a month. I cannot imagine that nets slow down air flow enough to create a powdery mildew issue. I guess also a lot of this depends on what you are spraying. Sulfur probably should not be sprayed so close to harvest. The other non-organic sprays, I don’t know, like copper based need to be close to the infection. Using systemic fungicides, you could hit the canopy and be alright.

 

[richinsd]

yes i have VSP. but i don't think that will make a difference in whether the spray gets through the net. whether you can actually hit your clusters???? i have no experience with the sprawl. for PM i alternate between rally/quintec/oil. no sulfur any more. i don't think the systemics actually travel all that far so still need good coverage. it's been hard to find any good data on my theory though.

 

[meridaen]

I’m still researching as to what I’m going to end up using post lag-phase, but certainly not Sulfur. I’m trying to stay away from systemics but I’ll probably move in that direction.

 

[AvaSullivan]

How is everything going?

 

[meridaen]

We’ve only just started the journey, my Sangiovese is about 6-7 leaves, Riesling 2-3, Antão Vaz about the same. Won’t be breaking the nets out until around Christmas Day or not long after.

 

[Obbnw]

Is that with VSP though @richinsd ? I just have a sprawl as the sun is ridiculous down here, so I’ll be throwing a net over the whole show. Good to know that I can spray with the nets on. I live on the edge of a protected wetlands so the birds are plentiful and moving on sans netting will result in zero grapes.

The birds found my grapes this year and I had to put up emergency netting.

The netting did negatively impact ripening and increased disease pressure. In places where the netting confined and bent leaves, ripening slowed down and powdery mildew increased. In areas where the netting didn't confine the grapes I didn't notice delayed ripening or increased powdery mildew.

my lesson is that I need to revise my pruning to reduce sprawl in areas where I need to anchor the netting.

I stopped spraying before I netted but do think spaying would not have been effective in the areas I confined/bunched.

Otherwise the netting worked great. A few birds trapped themselves in the netting the first couple of days but then they all disappeared.

 

[meridaen]

Good to hear, I’m interested to see how it goes.