Grapes dropping?

[Handy Andy]

My grapes are entering veraison, harvest in 4 to 6 weeks. yippee

I carried out a final spray last week against mildew, and used a leaf fertilizer.

I have noticed some clusters are dropping grapes to the floor whereas others are ok.

Was it a mistake to use a leaf fertilizer at this stage in the season?

The grapes do not appear to have been damaged by birds, although! I think some finches are taking an interest in my vines, might they be knocking them off?

The weather here is relatively mild and we have had no heavy rain or wind recently.

 

[Handy Andy]

Um

 

[Rice_Guy]

* I have one variety which will drop grapes, most of my Edelweiss has been replaced by Briana which holds better. ? what variety ?
* fertilizer a month out shouldn’t cause grapes to drop, I don’t encourage vegetative growth/ fertilize when I see fruit. The books say fruit has more flavor if it is stressed instead of watery/ luxuriant growth
* some of the chemicals will cause fruit drop however I will guess you spray with common stuff as Sevin or Captan which don’t seem to
* moisture stress can cause drop, most grape varieties resist stress

 

[balatonwine]

I have noticed some clusters are dropping grapes to the floor whereas others are ok.

Some causes:

1) Weather (which you said you did not have)
2) Birds
3) Insect damage (vines are self dropping berries that may contain internally growing young insects)
4) Varietal behavior

 

[Handy Andy]

Thanks all for the replies