The first steps in reducing problems is the initial soil preparation, nutrient supplies and watering. Petioles may become light red in color. Leaves are smaller' dark olive green and have a dull appearance. They can fade to a dull orange. There is a tendency for the leaves to curl downward and the leaf petioles to become darker red.
Brown spots develop interveinally on the under surface of the leaves.
The first symptoms are downward curling of the leaf, associated with a bronzing of the interveinal tissue. The interveinal tissue becomes a paler green and eventually dies, giving rise to interveinal scorch. In the final stages the leaves wither to an ashy-gray color and fall. There may be a marginal scorch on the older leaves. Your best defense is to check your plants daily or even twice daily, morning and evening, especially in the early stages of growth.