316 FLORIDA STATE HORTICULTURAL SOCIETY, 1960 than most varieties. They are good for cook many people like the flavor of other varieties ing. better, the Oliver is propagated at present more than any other variety in Dade County. It has The variety, Gold Nugget is said to be a an orange colored flesh and ripens in mid- synonym of Thales. However, the Gold Nugget at the Sub-Tropical Experiment Station is season. different from both Tanaka and Thales. The Among new varieties at the Sub-Tropical tree is much more upright and the fruit is Experiment Station, Fletcher and Red Royal larger, rounder and later in ripening. The fruit may show some promise. Both varieties have is tart when fully colored, and the tree is a shy very deep orange flesh though it is not a true bearer. This variety cannot be recommend red. These will need further evaluation before ed for South Florida conditions. they can be compared with other varieties. A so-called seedless variety has also been ob The Oliver variety which was described by tained but it has not yet produced a crop. Mrs. Krome in 1936 remains one of our choicest varieties. It bears heavily and the fruit REFERENCE 1. Krome, Mrs. I. 1936. Loquats. Fla. State Hort. Soc. is good to eat out of hand or cooked. Although Proc. 49: 143-145.

SPECIES OF SUSCEPTIBLE TO THE FIG MOSAIC VIRUS

Harry C. Burnett , including those in the genus Ficus and additional ones from other genera, have State Board of Florida been inoculated with buds infected with fig mosaic. One plant in the genus Cudrania and Winter Haven seven of Ficus have been found to be In April, 1958, several hundred fig , susceptible to this virus. The degree of mot Ficus carica L., from Italy, grown under post tling ranged from slight to severe, depend entry permit, and several hundred fig plants ing upon the response by the individual plants. from California were found in Florida, and all The following species have been found suscep were infected with the fig mosaic virus. The tible: Fiscus lucescens, (F. wightiana), F. disease was successfully transmitted from af jacquinifolia, F. rubiginosa (F. australis), fected to healthy fig plants by budding. F. retusa, (F. nitida), F. mallatocarpa, F. Studies were initiated to determine possible glomerata, an unidentified species of Ficus, susceptibility of other moraceous plants grow and Cudrania tricuspidata. ing in Florida to this vims disease. All the species listed above are new hosts Condit and Home (1) first reported fig for this virus, with the possible exception of mosaic from California in 1933, and later from F. rubiginosa (F. australis), although it was Texas in 1941 (2). Pittman, in 1935, (5) re reported from New Zealand as a suspected corded the presence of this disease in England, host by Ti and Procter in 1944. (4). Cudrania Puerto Rico, Kwangtung and Nanking, China, tricuspidata also is a new host, and is the first and New South Wales, Australia, and Ti and plant outside of the genus Ficus found to be Procter (4) in New Zealand in 1944. It was susceptible to this disease. reported from Georgia by Garren (3) in 1947. Eleven other moraceous plants have been Condit and Home (1) first described the inoculated by budding from virus-infected viral disease on Ficus carica and reported that plants. To date, none of them have shown any it occurred on practically all varieties of fig symptoms suggestive of this disease. Currently, wherever grown in California. They named they are under test to see if they are symptom- Ficus altissima, F. krishna and F. tsida as spe less carriers of the virus. Those inoculated cific hosts. (2). Li and Procter (4) suspected plants which show no symptoms after from F. retusa, F. repens, F. australis and F. macro- six to fifteen months are as follows: Morus phylla of showing symptoms of the disease, ruha, Humulus americanus, Ficus lyrata (F. but transmission from diseased to healthy pandurata), F. religiosa, F. elastica, F. aurea, plants of these varieties was not demonstrated. F. quercifolia, F. calophylloides, F. kirstingii, Since1958, virus-free plants in the family F. radulina and F. vogelii. BURNETT: FIG MOSAIC VIRUS 317

Symptoms green color of the affected areas contrasting Condit and Home (1) described the symp sharply with the normal green color of the toms of mosiac virus in fig, Ficus carica, as foliage. The borders of mosaic spots are, how follows: 'Tig mosaic manifests itself both on ever, usually indefinite, their light color blend the leaves and on the fruit. On the leaves the ing gradually with the dark green of healthy mosaic spots are sharply delineated, the light tissue. In some leaves, the spots are more or

Fig. 1. Symptoms of fig mosaic on Fieus eariea. (State Plant Board Photograph by Jerry Messec.) 318 FLORIDA STATE HORTICULTURAL SOCIETY, 1960 less uniform size, small and densely scattered This species gives the most pronounced over the surface. In other cases, they are of response of any of the plants tested. It is various sizes, of indefinite outline, and ap superior to F. carica in symptom-expression pearing as irregular patches of light green, and is now used as an indicator plant for the diffused widely throughout the blade of the fig mosaic virus. Leaf symptoms may be de leaf with no relation whatever to the position scribed as the same as those on F. carica, but of the leaf veins. Mosaic spots often are bor more accentuated. The leaves of this plant are dered by a rust-colored band, evidently caused normally a deeper green than those of the com by the death of epidermal or subepidermal mon fig. There is, therefore, a greater contrast cells. Seldom does the mosaic bring about an between the yellow or yellow-green mosaic actual necrosis or dying out of whole areas of pattern and the dark green background. Mo leaf tissue. saic-infected leaves are generally smaller to much smaller than normal ones, and there may "One manifestation of fig mosaic, which ap be extreme twisting, puckering and distortion. pears to be systemic, is the malformation of What appears to be a shock reaction results leaves. In some cases, certain twigs bear none after a plant is inoculated. Leaves are twisted but malformed leaves. In other cases, both and distorted, and may be reduced in size as malformed and normal leaves are found on the much as 90% of that of a normal leaf. Even same twig. Malformed leaves show an infinite tually, or within six to ten months, new leaves variety of shapes and sizes. become larger until they approach the size "The appearance of mosaic spots on the of normal leaves. At this time, they still con fruit is very similar to that on the leaves. The tinue to show the typical mosaic symptoms premature dropping of figs appears at times characteristic of this species. The earliest symp to be due to the presence of these mosaic spots toms show on the second flush of growth, on the surface of the fruit and on adjacent which is usually from four to six weeks after leaves." inoculation. Figure 2C shows symptoms on Leaf symptoms on infected fig plants grow F. lucescens. ing in Florida correspond to those described by Symptoms on an Unidentified Condit and Home (1). The premature drop Species of Ficus ping of figs, however, has not been observed on the limited number of plants under obser A mosaic pattern appears on leaves within vation, although a yellow streaking and spot six weeks after inoculation. This pattern is ting has been noted on a small percentage of distinct and loses little intensity, even after fruit. This symptom has been noted throughout twelve months. All or part of a leaf may show the whole growing season, but is more pro symptoms, but not all leaves on a given plant, nounced or evident in the spring of the year. or even on a given twig, show symptoms. The Occasionally, all or almost all the leaves show leaves that do show symptoms are reduced to at least some of the mosaic pattern, but usual about three-fourths the size of a normal leaf, ly it is limited to leaves on one or several and may be slightly deformed. Often, the limbs. Often, small twigs occurring on the mosaic pattern extends from one or both sides main trunk and near the ground level will show of the midrib and may cover the entire leaf, or symptoms while the balance of the tree will be only a part of it. When only a part of the leaf symptomless. See Figure 1 for symptoms on is involved, it is not uncommon to find small Ficus carica. circular to irregular yellow blotches scattered at or near the leaf margin. The mosaic pat The response to the virus by the eight new terns and blotches may have narrow rust- host plants listed above are so varied that a colored borders, similar to those described on description of the symptoms of each seems fig by Condit and Home (1). See Figure 2A desirable. for symptoms on Ficus sp.

Symptoms on Ficus lucescens (F. wightiana) Symptoms on Ficus rubiginosa Plants of Ficus lucescens were donated by First symptoms appear six to eight weeks Dr. Murray Gaskins of the United States after inoculation as a typical mosaic pattern Plant Introduction Garden, Miami, Florida, with leaf distortion and reduced leaf size, as where they are listed as PI 249537. noted on F. lucescens. Some of the leaves are BURNETT: FIG MOSAIC VIRUS 319

Fig. 2. Symptoms of fig mosaic on various hosts. A. on Fiscus sp.; B. on Fiscus retosa (F. nitida); C. on Ficus luces- cens; and D. on Cudrania tricuspidata. (State Plant Board Photographs by Jerry Messec.) only one-tenth normal size and extremely dis few of the leaves show symptoms. Figure 2B torted. Infected plants become stunted, new shows symptoms on Ficus retusa. growth lacks vigor, and almost all leaves show some marks of the virus, either as a mosaic Symptoms on Ficus jacquinifolia pattern or as distortion, or both. Symptoms on this species are less conspic uous than any so far described. The whole leaf This species also was donated by the United is not involved as in other species, but scatter States Plant Introduction Center at Miami, ed areas of mosaic patches may be seen any and is listed as PI 90711. where along the leaf. The virus causes a slight reduction in the size of the leaf, but very little Symptoms on Ficus retusa (F. nitida) distortion. The over-all symptoms are ob This is one of the most common species of scure, and with only a casual observation, an Ficus in Central and Southern Florida. Symp infected plant may easily be overlooked. toms are not as striking as on the above men First symptoms show up in six weeks after tioned plants. Nevertheless, the mosaic pattern inoculation, as with other species tested. and the slightly smaller and distorted leaves are conspicuous, though less pronounced as in Symptoms on some other species. Infected plants of this Ficus mallatocarpa and F. glomerata species tend to have a lighter green than nor Four seedlings of F. mallatocarpa were se mal appearance, which tends to give less con cured from the U. S. Plant Introduction Gar trast with the yellow-green mosaic pattern. dens and are listed by them as PI 244611. Generally, the leaves showing symptoms are The symptoms of infection expressed in slightly smaller than those not showing symp these two species are described together since toms. Some dwarfing has been noted, especial their responses to the virus are practically ly on branches where a considerable number identical. The plants seem to be symptomless, of leaves show infection. However, branches but in some cases one twig, or only one leaf are quite vigorous when none, or only a very on an entire plant may show symptoms which, 320 FLORIDA STATE HORTICULTURAL SOCIETY, 1960 when noted, are expressed as a mosaic mot oped clearly visible symptoms. These symp tling of the entire leaf or as a leaf only half toms again became weaker in the succeeding the normal size. Some inoculated plants may flushes of growth. Figure 2D shows typical show no symptoms. Yet, when buds are taken symptoms on Cudrania tricuspidata. from these symptomless plants and placed on Studies of other moraceous plants, particu healthy F. carica or F. lucescens plants, the larly those grown in Florida, are being con- typical fig mosaic symptoms appear. tinued-

Symptoms on Cudrania tricuspidata LITERATURE CITED Cudrania tricuspidata was the only mora- 1. Condit, I. J. and W. T. Home. 1933. A mosaic of fig in California. Phytopathology 23:887-896. ceous plant outside the genus Ficus which 2. Condit, I. J. and W. T. Home. 1941. Further notes on fig mosaic. Phytopathology 31:561-565. proved susceptible to this virus. The first 3. Garren, Kenneth H. 1947. Fig mosaic in Georgia. symptoms showed within six weeks after ino Plant Disease Reporter 31:300-301. 4. Li, Tai-Yung and C. H. Procter. 1944. A virus culation as yellow blotches, often but not al disease of fig in New Zealand. The New Zealand Jour, of Sci. and Technology 26:88-90. ways associated with the midrib or main 5. Pittman, H. A. 1935. Fig leaf mottle. W. Australian veins. The outer periphery of the blotches be Dept. Agric. Jour. 12:196. came yellow-green and finally blended into the ACKNOWLEDGEMENTS normal green of the leaf. Although there was The author is indebted to Mr. Charles Bickner, Plant Inspector, State Plant Board of Florida, who first found the no noticeable reduction in leaf size, some dis fig mosaic in Florida and submitted it to the Winter Haven Laboratory. Appreciation is due Dr. Murray Gaskins, U. S. tortion did occur, especially if the blotches Plant Introduction Garden, Miami, Florida, for many of were confined to one side of the leaf. Symp the Ficus species which he supplied for use in these studies; to Mr. Erdman West, Mycologist, West Florida Agricultural toms of infection decreased as new growth Experiment Station, Gainesville, Florida, for identification of the species of Cudrania; and to Mr. Stanley N. Brooks, progressed, until only a scattered leaf was Research Agronomist, USDA, Corvallis, Oregon, who sup noticeably affected. When older plants were plied hop cuttings used in these studies; and to Mr. Jerry Messec, State Plant Board Photographer, for the pictures with cut back, the new growth that followed devel which this paper is illustrated.

PROGRESS IN THE DEVELOPMENT OF GRAPE VARIETIES

FOR FLORIDA

L. H. Stover dred acres of Concord, Ives, Worden, and Niagara were grown in the vicinity of Orlando. Florida Agricultural Experiment Stations The ultimate failure of these grape plantings Watermelon and Grape Investigations influenced the United States Department of Laboratory Agriculture to establish an experiment in 1899 at Earlton, Florida, designed to ascertain why Leesburg standard cultivated varieties of grapes sicken Cultivated grapes were introduced into ed and died at a relatively early age. Baron Florida at various times since the earliest von Luttichau conducted the work and within days of colonization (1). Spanish, French, a few years reported that attacks of various and English settlers endeavored to establish fungi were responsible. In the meantime in Vitis vinifera L. varieties so that they might terest in commercial viticulture in Florida dis duplicate the wines of their homeland. With appeared almost entirely. the possible exception of the Key Grape on About 1920 the Texas "Post-Oak" hybrid the Florida Keys, all plantings of pure V. grapes (2) developed by Colonel T. V. Mun- vinifera grapes in Florida followed the same son from Vitis lincecumii Buckley were intro general pattern of decline and failure. duced and quickly aroused interest in the At the close of the Civil War settlers at possibilities of commercial grape culture, par tempted to establish in Florida the Vitis ticularly in the central ridge area. Over a labrusca L. varieties of northeastern America. period of about five years some 5000 acres These vineyards at various locations thrived were planted to the Munson hybrids. Superior briefly. Between 1885 and 1895 several hun- among these were Extra, Carman, R. W. Mun son, Bailey, and Armalaga. About 1923 the Florida Agricultural Experiment Station Journal Series No. variety Florida Beacon, which later was found 1167