Yellowing in older leaves that show an inverted V pattern near the base of the leaves
White patches on stems or pink or brown raised dome like structures on leaves and stalks about 3-5mm
Black sooty growth covering any part of the leaf, stem or branch of plants. Caused by the presences of sap sucking insects on the plants such as aphids, scale and mealybugs.
Thrips suck the sap, leaving a white mottled appearance on leaves. Other symptoms are browning on petals and fruit, and flower drop.