The first time I saw the fall colors out in the vineyard, I made an assumption. White grape leaves turn yellow and red grape leaves turn red. I was wrong. But I've never figured out what's right. Does the leaf color have to do with the variety of grape? How does that explain varying color in parcels that are planted with the same variety of grape? Is leaf color based on weather, pollen, or some other factor? Is it totally random?
Bits of orange and red among the golds and yellows.
I must admit that I've done zero research on this vital issue of our time. The whys and wherefores of grape leaf colors continue to elude me. But they're pretty.
Maybe I’ll do some reading, between unpacking boxes and flattening paper, on the colors of grape leaves. Maybe I‘ll leave it to you.
ReplyDeleteYellow leaves contain xanthophyll, orange leaves contain carotene, and red leaves contain anthocyanin.
ReplyDeleteIn red grape varieties, leaves turn red between veins starting from the edges, and as deficiency gets severe, they turn purple. In white grape varieties, deficient leaves turn chlorotic (pale yellow or white), due to insufficient chlorophyll.(From "Good Fruit Grower")
From AI synopsis:
Grape leaves can turn different colors for a number of reasons, including nutrient deficiencies, the season, and viruses:
Nutrient deficiencies: Grape leaves can turn different colors depending on which nutrient is deficient:
Magnesium or zinc deficiency: Leaves turn yellow, but the veins remain green.
Phosphorus deficiency: Leaves turn red, but the veins remain green.
Potassium deficiency: Red grape leaves turn red between the veins starting from the edges, and as deficiency gets severe, they turn purple. White grape varieties deficient leaves turn chlorotic (pale yellow or white).
Who cares? Grapes don't matter until they become wine :-)
ReplyDelete