Rate of application of zinc sulfate: Mildly rosetted trees—apply 5 pounds zinc sulfate (36 percent) annually for 2 to 3 years. Severely rosetted trees—apply 5 to 10 pounds zinc sulfate (36 percent) annually until rosette symptoms disappear. Time and method of application: Apply zinc sulfate to the soil around trees in late February or early March. Broadcast zinc sulfate under the tree from the trunk to several feet beyond the limb canopy. Disking, harrowing, or any operation that mixes the zinc sulfate with the soil, is desirable to prevent washing away and surface soil fixing of zinc. LICHENS Lichens commonly are found growing on the branches and trunks of pecan trees, especially in humid areas and river bottom orchards having poor air drainage. Lichens are nonparasitic to the pecan tree, but merely attach themselves to the bark surfaces. Lichens grow equally well on rocks, fence posts, bricks and other objects. There are several types of lichens that occur on pecan trees, none of which are damaging except perhaps in appearance to the trees in cases of extremely heavy infestations, Figure 5. [Illustration: Figure 5. Lichens commonly found on the bark of pecan trees. Left, a fan-shaped type. Right, an erect-branched type.] _Control._—The occurrence of lichens in trees regularly sprayed with copper-containing fungicides is rare. ARTICULARIA LEAF MOLD Articularia leaf mold caused by the fungus _Articularia quercina_ (PK) Hoehn is a disease of minor occurrence and importance. The disease occurs most commonly following rainy periods and in areas of high relative humidity in the leaves of trees of poor vigor. The fungus produces on the lower surfaces of the leaves a conspicuous growth of white tufts which contain masses of spores, Figure 6. [Illustration: Figure 6. Articularia leaf mold fungus, showing white tufts on lower leaf surfaces of pecan leaflets.] _Control._—Articularia leaf mold does not occur in trees or in orchards which have been sprayed for disease control. A single application of fungicide such as zineb at 2 pounds per 100 gallons of water when the disease is first detected is usually sufficient to control Articularia leaf mold disease. PINK MOLD Pink mold, _Cephalothecium roseum_ Corda, usually occurs on nuts infected with the scab fungus. The pink mold fungus apparently enters the nuts through scab lesions on the shucks and continues to produce masses of pink spores on shuck surfaces until late fall. The fungus sometimes invades the kernel of thin-shelled pecan varieties causing “pink rot” which is characterized by an oily appearance of the nut shell and a rancid odor. _Control._—Pink mold rarely occurs on the shucks of nuts in the absence of scab disease. In areas where scab disease control is regularly practiced pink mold is not a problem. SPANISH AND BALL MOSS