Anthracnose..harvest or scrap?

[Rob Kneeland]

I was out of the country until Jul 1. I planned on accepting that there'd be no harvest this year, would prune the vines back and get on it next year. But I returned to a messy, but heavy crop on my 35 Marquette vines. Unfortunately, with no spraying and a humid June, I have anthracnose pretty badly. I'd say that 90% of the grapes are blemished. I've started sulphur spraying 2x per month but I fear it is too late.

Should I go ahead and harvest anyway? Not sure what impact the fungus would have on the wine.

I will prune back this winter and do a lime sulphur dormant spray. And will safely dispose of the cuttings.

I would always get anthracnose on my cucumbers so I guess it is everywhere on my property.

Thanks
Rob

 

[Hazelemere]

fermenting on the skins will probably give you dreck.

If you press them and then treat the fermenting juice with bentonite you may get something okay i.e. keep the mildew bitterness out of the wine

 

[Rice_Guy]

i.e. keep the mildew bitterness out of the wine

Is this a thing?
I have been listening to the local winery saying that bitter comes from the oils that create Lambrusco / foxy flavors. Their answer has been to pick early while it is high acid.

 

[Hazelemere]

Is this a thing?
I have been listening to the local winery saying that bitter comes from the oils that create Lambrusco / foxy flavors. Their answer has been to pick early while it is high acid.

yes its a thing

https://www.awri.com.au/wp-content/uploads/2015/09/managing-powdery-mildew-in-the-winery.pdf

 

[Hazelemere]

Powdery Mildew spray - best one I've seen and I'll explain why in a minute:

~2/3 cup of powdred sulphur e.g. Kumulus S
~2/3 cup of potassium bicarbonate
~ 1 cup of insecticidal soap (e.g. anything containing the potassium salts of fatty acids - e.g. Later's Trounce)

2 gallons of water.

1. de-leaf near any cluster
2. spray the fruit clusters first , soaking them
3. then spray the leaves and canes
4. spray the fruit again

Try to spray when you have no rain the forecast for 48 hours

Why this cocktail works:

1. mildew repels water because it is hydrophobic (hates water)
2. insecticidal soap wets mildew because is semi-hydrophobic on one part of its molecule i.e. the fatty acid part.
3. mildew hates potassium bicarbonate because it kills mildew spores.
4. potassium bicarbonate can stick to mildew spores if it has a semi-hydrophobic carrier like insecticidal soap.
5. sulphur can stick to mildew spores to kill them if it has a semi-hydrophobic carrier like insecticidal soap.

 

[Rob Kneeland]

I only sprayed sulphur once and this late in the season they look pretty good considering what they looked like earlier!! I will go ahead and harvest per usual. Seems like I am only at 15 brix. Looks like another 2 weeks or so. Probably 2x last year's crop.