Question about bagging grapes.

[Masbustelo]

Does anyone have any experience with using bags to protect the grapes from birds? I see that 100 years ago it was being experimented with, and I see that Japanese sources are selling them. I see some are using mesh bags and muslin as well. Would it protect against disease or increase it?

 

[Masbustelo]

Here is a video. [ame]https://www.youtube.com/watch?v=9hsdH688_Es[/ame]

 

[salcoco]

it certainly would reduce the air flow. reduce air flow increase fungicidal disease? it also depends on how many grapes you are wanting to protect. I always found that netting was the best preventive from bird poaching grapes. If you only have a few plants many nurseries have garden bird netting available. if a vineyard you need a commercial source of vineyard supplies.

 

[Masbustelo]

Salcoco Logic would certainly support your observation but subjective evidence doesn't. In grape production in other parts of the world it seems it (bagging) is common practice. I've been trying to find a technical study and haven't located one. The evidence I have come up with is that it increases quality, decreases disease pressure and is less expensive for the small producer than netting.[ame]https://www.youtube.com/watch?v=Jyyq7hHbH3o[/ame] It seems to be common practice in Japan which has both high land costs and high labor costs.

 

[Johny99]

So, sunlight into wine and WSU research is focused on getting sunlight onto the clusters. So, bagging seems counter productive from that perspective. On the other hand, in Napa some talk about using shade cloth to reduce raisening.

As for Japan, they are incredibly fussy about table fruit quality- visually. Around here, apples for export to Japan are commonly bagged. Nothing to do with taste, it is all about being blemish free. So, I wonder where bagging is done is it wine grapes or table grapes? For wine grapes, blemishes don't matter, we squish them anyway, but the lovely constituents that are developed as the grapes ripen are what we are after.

That said, netting is cheap and so are bread clips and twist ties. I'm of the opinion it takes less labor to net a vine or a row than to bag each cluster.

 

[Masbustelo]

All of the above said it appears that no one has done a serious academic study to provide test controlled data on this subject. Hence and alas it's all conjecture.

 

[treesaver]

I have thought very seriosly about it. I have lost the majority of my grapes here several years due to wasps and flies. I have posted f this in the past. I have enough vines now though, that it would be very labor intensive. By doing that, I would be able to let the fruit hang and get the brix where I want it. Still kicking the can around!

 

[user 36973]

All of the above said it appears that no one has done a serious academic study to provide test controlled data on this subject. Hence and alas it's all conjecture.

Sounds like you are signing yourself up for a project this year!

 

[Masbustelo]

If one were to overlook labor costs I wonder if best practice is to bag? The comments I have seen indicate longer hang time, better control of pH and TA regarding harvest time and higher quality of fruit.

 

[treesaver]

If I can locate some bags that fit.....the right size for the job, I'm going to give it a go. Maybe on a small scale to get my feet wet! I have been considering doing this for several years....I'll let you know how it goes! If nothing else, it would be worth it just to keep the spiders out of the bunches. There is always a ton of them to deal with. More protein!

 

[salcoco]

possibly a query to one of the universities or Geneva would provide some insight. Does anyone have a contact?

 

[Masbustelo]

Treesaver look for waxed bakery bags. I am in my second year so only have a few to bag.

 

[treesaver]

Masbustelo, I spent the noonhour lokking at bags, and found some regular old hardware bags for like 13.00 bucks for 250, and you have to buy two bunches for a total of 500. Had almost pulled the pin on them, and read your post. I haven't the fogiest were to find bakery bags, and there are no bakerys around here. 500 would definately get my feet wet, but I haven't a clue ss to how many it will take. Outside of counting bunches!

I would think a regular brown sack would last 2-3 months and do the job. The gguy in the first clip was talking about organza bags....said they were cheap, he only had a half dozen bunches on his vines that I could see. Of course it's cheap if you don't need thousands!

Thanks for the thought, I'll look into bakery bags and see if that will work. Lee

Ha, the virtual ink wasn't dry yet, looked in the U-Line catalogue, and bang, there they are! They have Glassine bags, #S-11592 that is 4 1/2 X 3 1/4 X 9 3/4 for 52 buck for a thousand. That would keep it in budget!

 

[Masbustelo]

Treesaver I think the organza bags would let in water with it's associated problems. What I have seen with the bags is they make a 1.5 inch slit on each side, remove the leaf nearest the bunch, and then bring the bag over the vine and use a small stapler on each side. https://www.staples.com/Rapid-K1-Cl...apler-50-Sheet-Capacity-Chrome/product_504548 What variety of grapes are you growing?

 

[treesaver]

Masbustelo, I have about fifty norton and about thirty frontenac, as well as about 60 concord with a few cataba thrown in. I don't care as much about the concord, but would really like to try the bags on the frontenac and norton. I might add, that there are some one and two leaf vines in the frontenac and the norton, but at least 2/3 of the vines are three to eight years old. I've been rooting cuttings for about twelve years and expanding them. The concord was planted first, and now another twentysix verona. I'm 70 years old and love to work, but I might have to hire some help.....pay them in wine!

 

[Masbustelo]

I"m thinking one advantage to the bags would be that you could use sulfur as late as you wanted.

 

[Treeman]

I tried bags 2 yrs ago on a few vines and they worked well for a few weeks longer hang time than unprotected the previous year. Then squirrels, raccoons, or birds must have had enough and wiped out my 20 or so bunches of ripe grapes in one weekend when I was away. Nothing but ripped up bags and a few grapes left.

 

[Masbustelo]

I suspect raccoons are the next big challenge. Im trying to figure out an electric wire configuration. Im in the city and I can get a permit to trap them. I had one before and the wildlife official said I was supposed to drown them. I'm a little squeamish and not hard hearted enough to do it. But open to change.

 

[treesaver]

***** are something I know about! I've been a trapper all my life, and they are plentiful, especially since this last downturn of the fur market. The only way to discourage a **** is an electric fence. The problem with electric fences, is if a blade of grass grows up to the wire unnoticed, it can ground out the whole fence, and the ***** will keep coming back to a food source for as long as it is there. The best way is to trap them....in live traps, and kill them. I nderstand your sympathies, but it comes down to you or them. All the farmers hate ***** for all the same reasons, they will just destroy anything that is food to them! I would take them out of town and use a twenty two for dispatch, cause finding deep enough water in town, might be hard to do....it would have to cover the trap completely by several inches. Good luck, to protect your grapes, you will have to harden your heart!

 

[treesaver]

The first wire needs to be 5-6 inches off the ground. The next, about 10 and the next about 8 inches higher. Make sure they cannot climb up on something or a tree that hangs over the fence, they can avoid the fence, they will be on your grapes! They can get pretty creative.