Thank you for all your responses.
Here is more information:
Growing outdoors on a plot that has been well tended for over a decade with compost, feather meal, blood meal, mulch. Grew either peas or corn on it. Organic methods.
Watered overhead for a while but not for the last month. Now us...
Growing outdoors in Michigan
Durban Poison and White Widow
Plants growing very well, some are over 9 feet tall
The attached photos show my concern - dark purple color on the leaves starts at the end of branches. When rubbed, the coloring does not smug so I doubt it is a fungus or mold (but I...