It is important to keep in mind that not all leaf scorch is fungal leaf scorch. Mites, nutritional disorders and dry weather all cause various kinds of pecan leaf scorch. If leaf scorch appears, it is important to determine the exact cause so that corrective measures, when available, can be taken. Brown spot only attacks mature leaves. It is not found before June or July.
Infections appear as reddish brown, more or less circular spots.
These spots cross over the leaflet veins. Some spots may show grayish concentric rings at the margin. As the spots age, they become irregular in shape. Brown spot is more common in areas of high rainfall and low fertility. Under these conditions brown spot can cause severe leaf drop in unsprayed orchards.