Figure 1. The initial lesions of this leaf spot disease are pin point water-soaked appearing spots. As the spot expands, the center becomes gray with water-soaked edges As the lesions continue to expand, a yellow halo may be observed. Coalescing of expanding lesions are observed until large areas of blighted tissue result. Photo by M. L. Elliott.
Figure 4. A leaf affected by both Graphiola leaf spot and Stigmina leaf spot. Signs of Graphiola phoenicis are the small back bodies (sori), many with filaments emerging from the sori. Stigmina palmivora symptoms are the large brown spots with dark edges and darker but flat centers. In some cases, a G. phoenicis sorus is superimposed upon the S. palmivora leaf spot. Photo by M. L. Elliott.
Figure 3. Leaf spot that begins as a black spot with distinct yellow halo. As the lesion expands or lesions coalesce, the affected area becomes a leaf blight and the center becomes a gray color. Photo by T. K. Broschat.
Figure 6. A leaf spot symptomatic leaf segment of the leaf in Figure 1 was placed under high humidity. The result was growth of the fungus from some of the spots. Note fungal growth is only associated with the leaf spot symptom and not with the healthy green leaf tissue. Photo by M. L. Elliott.
Figure 5. Spots are initially black with no halos. As the spot expands, the center becomes tan and is outlined by a brown to brownish-black edge, but no yellow halo. The leaflet in the lower-left corner has large areas of necrotic tissue. The leaf spot is superimposed on iron deficiency symptoms. Photo by M. L. Elliott.
Figure 1. Cocos nucifera in various stages of lethal yellowing disease development. Healthy palms are in the background. Palm in foreground is in early to mid-stages of the disease. Palm on the left has died but dead leaves are still attached to the trunk. Trunks without canopies died previously from LY. Photo by N. A. Harrison, University of Florida.
Figure 6. Spear leaf of this Phoenix sylvestris has collapsed and is hanging down out of the canopy on the right side of the trunk. Very few of the oldest leaves have discolored. Photo by M. L. Elliott.
Figure 5. Leaves of a Phoenix canariensis with lethal yellowing do not turn yellow, but are various shades of reddish-brown to dark brown or gray. The spear leaf had died on this palm weeks prior to when this photo was taken. Photo by N. A. Harrison., University of Florida
Figure 1. Magnesium deficiency symptoms on Phoenix roebelenii. Note the broad yellow bands along the outer margins of the leaves, but distinctly green central portions of the leaves. Photo by T.K. Broschat.
Figure 2. Magnesium and potassium deficiency symptoms on Phoenix canariensis. The broad yellow-banded mid canopy leaves show Mg deficiency, while the oldest leaves show leaflet tip necrosis (K deficiency). Photo by T.K. Broschat.
Figure 4. Magnesium-deficient older leaf of Livistona rotundifolia showing broad yellow band around entire leaf as well as a yellow band along margins of single leaf segments in upper left. Photo by T.K. Broschat.
Figure 2. Large, dark lesions have formed near or on the leaf base of all the rachides of this Phoenix roebelenii canopy. These lesions often continue to expand, and the fungus will infect the spear leaf and the apical meristem causing a bud and crown rot. Photo by T. K. Broschat.
Figure 1. This Phoenix canariensis leaf has green leaflets on one side of the rachis and necrotic leaflets on the opposite side. There is a reddish-brown stripe on the rachis that corresponds to the necrotic leaflets. Photo by M. L. Elliott.
Figure 4. A single Washingtonia robusta leaf where a quarter of the leaf blade is still green, but the remaining leaf segments are necrotic. The petiole has a reddish-brown stripe on the same side where the necrotic leaf segments are located. Photo by M. L. Elliott.
Figure 5. This Livistona chinensis leaf has a reddish-brown stripe on only one side of the petiole due to petiole blight. Part of the leaf blade is necrotic and the other portion is still green. Photo by M. L. Elliott.
Figure 10. Late stage potassium deficiency in coconut palm (Cocos nucifera) showing chlorotic, necrotic new leaves and tapered trunk. This palm died shortly after this photo was taken. Photo by T.K. Broschat